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Sample records for adriatic dense water

  1. A long and winding road: Skeletonema sp transport by Northern Adriatic Dense Waters to the Southern Adriatic Pit.

    NASA Astrophysics Data System (ADS)

    Marcello Falcieri, Francesco; Bernardy Aubry, Fabrizio; Barbariol, Francesco; Benetazzo, Alvise; Bergamasco, Andrea; Boldrin, Alfredo; Bonaldo, Davide; Carniel, Sandro; Finotto, Stefania; Sclavo, Mauro

    2015-04-01

    The semi enclosed Adriatic Sea is a sub basin of the Mediterranean Sea located in its northeastern part; it has a shallow northern part (average depth of 40 m) and a deep Southern Adriatic Pit (SAP) that reaches 1200m. The presence of a wide continental shelf exposed to strong heat and momentum fluxes during winter months makes the Northern Adriatic a formation site of dense waters, generally referred to as Northern Adriatic Dense Water (NAdDW). Once produced, it moves south as a quasi-geostrophically adjusted vein , flowing along the Italian coast and enters the SAP giving origin to descent and cascading dense shelf water bringing into the deep layers oxygen, nutrients and organic compound. In February 2012 a long and intense cold air outbreak, with strong Bora winds, interested the northern part of the Adriatic sea causing a drop in water temperature to less than 6 °C and an increase in density to values as high as 1030.2 kg/m3 (likely the maximum values since 1929). This resulted in a massive production of NAdDW. In order to study the behavior of the NAdDW vein, a rapid response 2 legs cruise (ODW2012) was organized in the southern Adriatic. During the cruise, along with physical and chemical measurements, water and phytoplankton samples were collected at different depths. Usual abundance and distribution with a general decrease in phytoplankton abundance from the surface to the bottom were found in all stations with one exception. The bottom sample of a station located roughly 40 km at 120 m depth in front of Gargano showed a significantly high dominance (40%) of the small diatom Skeletonema sp whose flowering is typical in the surface waters of the northern Adriatic in late winter. The physical parameters of the water column showed signs of the passage of the dense water vein (lower temperature and higher dissolved oxygen concentrations) hence it was hypothesized that those diatoms were actively transported by the NAdDW near-bottom stream. A further

  2. Dense water generation on a shelf: the case of the Adriatic Sea

    NASA Astrophysics Data System (ADS)

    Vilibić, Ivica; Supić, Nastjenjka

    2005-12-01

    The paper overviews recent and past studies of preconditioning, generation and spreading of North Adriatic Dense Water (NAdDW), by analysing both transient episodes and climatological data. The importance of wind stress, heat and water fluxes, and particularly river discharges during the preconditioning and generative period is emphasized, as well as the advection of saline levantine intermediate water from the southeast. After the generation, NAdDW affects deep and bottom layers of the middle and south Adriatic Sea, flowing as a dense current and mixing with the adjacent waters; it can be traced even in the Otranto Strait, contributing to the formation of deep water in the Eastern Mediterranean. Objective shortcomings and the projections in NAdDW investigations are also discussed, due to their high importance in the circulation of the Adriatic Sea, which may relate other similar basins around the world.

  3. Observations on a bottom vein of dense water in the southern Adriatic and Ionian seas

    NASA Astrophysics Data System (ADS)

    Bignami, Francesco; Salusti, Ettore; Schiarini, Silvia

    1990-05-01

    We discuss the motion and spreading of a bottom vein of very dense marine water, which originates (σ ≥ 29.4) in winter through cooling and evaporation processes resulting from the violet Bora wind blowing over the shallow North Adriatic Sea into the deepest layers of the southern Adriatic and Ionian seas (eastern Mediterranean basin). Our analysis is focused on the peculiar physical processes that control this bottom flow. We first describe the vein motion in the southern Adriatic Sea in which this current follows approximately the isobaths (in partial accordance with the conservation of potential vorticity) and the main mixing process of dense water with Levantine Intermediate Water occurring in an offshore-oriented canyon near Bari. This canyon causes a deepening and flattening of the original vein of dense water, such that downstream the water can be observed only on the Otranto Sill (at depths of ≈ 800 m with σ ≈ 29.25). The subsequent flow in the Ionian Sea follows approximately the 900-m isobath in the Gulf of Taranto and along the Calabrian and east Sicilian coasts, in agreement with the results of Smith's and Killworth's theoretical models of steady motion of density driven currents over a regular slope, in a rotating system, for stratified fluids.

  4. Dense water formation and BiOS-induced variability in the Adriatic Sea simulated using an ocean regional circulation model

    NASA Astrophysics Data System (ADS)

    Dunić, Natalija; Vilibić, Ivica; Šepić, Jadranka; Somot, Samuel; Sevault, Florence

    2016-08-01

    A performance analysis of the NEMOMED8 ocean regional circulation model was undertaken for the Adriatic Sea during the period of 1961-2012, focusing on two mechanisms, dense water formation (DWF) and the Adriatic-Ionian Bimodal Oscillating System (BiOS), which drive interannual and decadal variability in the basin. The model was verified based on sea surface temperature and sea surface height satellite measurements and long-term in situ observations from several key areas. The model qualitatively reproduces basin-scale processes: thermohaline-driven cyclonic circulation and freshwater surface outflow along the western Adriatic coast, dense water dynamics, and the inflow of Ionian and Levantine waters to the Adriatic. Positive temperature and salinity biases are reported; the latter are particularly large along the eastern part of the basin, presumably because of the inappropriate introduction of eastern Adriatic rivers into the model. The highest warm temperature biases in the vertical direction were found in dense-water-collecting depressions in the Adriatic, indicating either an inappropriate quantification of DWF processes or temperature overestimation of modelled dense water. The decadal variability in the thermohaline properties is reproduced better than interannual variability, which is considerably underestimated. The DWF rates are qualitatively well reproduced by the model, being larger when preconditioned by higher basin-wide salinities. Anticyclonic circulation in the northern Ionian Sea was modelled only during the Eastern Mediterranean Transient. No other reversals of circulation that could be linked to BiOS-driven changes were modelled.

  5. Po River plume and Northern Adriatic Dense Waters: a modeling and statistical approach.

    NASA Astrophysics Data System (ADS)

    Marcello Falcieri, Francesco; Benetazzo, Alvise; Sclavo, Mauro; Carniel, Sandro; Bergamasco, Andrea; Bonaldo, Davide; Barbariol, Francesco; Russo, Aniello

    2014-05-01

    The semi enclosed Adriatic Sea, located in the North-Eastern part of the Mediterranean Sea, is a small regional sea strongly influenced by riverine inputs. In its northern shallow sub-basin both the physical and biogeochemical features are strongly influenced by the Po River (together with some other minor ones) through its freshwater plume, by buoyancy changes and nutrients and sediments loads. The major outcomes of this interaction are on primary production, on the rising of hypoxic and anoxic bottom water conditions, on the formation of strong salinity gradients (that influence the water column structure and both coastal and basinwide circulation) and on the formation processes of the Northern Adriatic Dense Water (NAdDW). The NAdDW is a dense water mass that is formed during winter in the shallow Northern Adriatic under buoyancy loss conditions; it then travels southwardly along the Italian coasts reaching the Southern Adriatic after a few months. The NAdDW formation process is mostly locally wind driven but it has been proved that freshwater discharges play an important preconditioning role, starting since the summer previous to the formation period. To investigate the relationship between the Po plume (as a preconditioning factor) and the subsequent dense water formation, the results obtained by a numerical simulation with the Regional Ocean Modelling System (ROMS) have been statistically analyzed. The model has been implemented over the whole basin with a 2 km regular grid, and surface fluxes computed through a bulk fluxes formulation using an high resolution meteorological model (COSMO I7). The only open boundary (the Otranto Strait) is imposed from an operational Mediterranean model (MFS) and main rivers discharges are introduced as a freshwater mass fluxes measured by river gauges closest to the rivers' mouths. The model was run for 8 years, from 2003 to 2010. The Po plume was analysed with a 2x3 Self-Organizing Map (SOM) and two major antithetic patterns

  6. Modelling the formation of dense water in the northern Adriatic: Sensitivity studies

    NASA Astrophysics Data System (ADS)

    Vilibić, Ivica; Mihanović, Hrvoje; Janeković, Ivica; Šepić, Jadranka

    2016-05-01

    This study aims to document the effects of imposing different river runoff forcing and tidal forcing to the dense water formation (DWF) rates and dynamics in a semi-enclosed sea. An extreme DWF episode that occurred in the winter of 2012 in the shallow northern Adriatic Sea during a prolonged cold bora wind outbreak event has been reproduced using a one-way coupled atmosphere-ocean modelling system comprised of the atmospheric Aladin/HR mesoscale model and ocean ROMS model. Three different river runoff forcing and tides/no tides scenarios were imposed on the model. The introduction of tides and river climatology instead of real rivers did not substantially change the modelled DWF transports and volumes, whereas the simulation using the old Raicich climatology resulted in a substantial freshening of the entire Adriatic that reduced or prevented the DWF at sites in the northern and northeastern Adriatic. The necessity of using an up-to-date river runoff climatology to properly reproduce the DWF in semi-enclosed seas is emphasised.

  7. Observations of a vein of very dense marine water in the southern Adriatic Sea

    NASA Astrophysics Data System (ADS)

    Zoccolotti, L.; Salusti, E.

    1987-06-01

    A bottom vein of dense water has been observed in the course of hydrological measurements carried out in three different periods—November 1980, February 1981 and June 1983—on the southern boundary of the shelf of the Adriatic Sea. The basin is renowned for cold, dense marine water generated in its northern portion by the Bora. Characteristic values of temperature, salinity and density of the central part of this vein of dense water are as follows: T ⋍ 13.70°C, S ⋍ 38.65‰ and σ 1 ⋍ 29.09 in November 1980; T ⋍ 12.4°C, S ⋍ 38.6‰, σ 1 ⋍ 29.3 in February 1981; and T ⋍ 12.52°C, S ⋍ 38.47‰ and σ 1 ⋍ 29.00 in June 1983. This water flows into the Southern Adriatic Trough, where it mixes with the Levantine type water. It follows the Italian shelf break at a depth of 100-300 m, gradually deepening until it reaches S. Maria di Leuca. The resulting water flows into the Ionian Sea through the Otranto Channel (740 m deep). An early hypothesis of Pollak is that this mixed water provides the main source of the abyssal water of the eastern Mediterranean Sea. A theoretical analysis, based on the classical steady model of Smith and a recent study by Shaw and Csanady, has allowed the fluxes to be estimated as 0.6-0.8 10 5 m 3 s -1 at the moment of maximum flux.

  8. Dense water formation in the Southern Adriatic Sea and spreading into the Ionian Sea in the period 1997 1999

    NASA Astrophysics Data System (ADS)

    Manca, B. B.; Kovaĉević, V.; Gaĉić, M.; Viezzoli, D.

    2002-06-01

    Hydrographic and current measurements conducted during the period from March 1997 to March 1999 in the Southern Adriatic and in the Otranto Strait provide clues to the mechanisms of dense water formation and its spreading in the Ionian Sea. The hydrographic surveys covered the successive phases of preconditioning, convection, vertical mixing and spreading. The sub-basin scale cyclonic circulation, the presence of highly saline and dense water in the intermediate layer and winter outbreaks of cold and dry continental air are verified as necessary prerequisites to open-ocean deep convection. However, in two winters, surface cooling and surface buoyancy fluxes were not of sufficient intensity, and the convective mixing reached only intermediate depth of ˜400 m in 1998 and ˜700 m in 1999. The ventilated convective cell in the centre of the gyre had density of ˜29.16 kg m -3, which was lower than the typical density ( σθ˜29.24 kg m -3) of the water that resides in the bottom layer of the southern basin (Adriatic Deep Water-ADW). In addition, dense waters from the northern shelf region contributed in filling up the Southern Adriatic deep reservoir. During more severe winter in 1999, two concomitant processes were observed: convection in the centre of the gyre and advection along the shelf of much denser waters ( σθ˜29.34 kg m -3), which, originating from the Northern Adriatic (NAdDW), sunk at the shelf-break and mixed with the resident bottom water in the Southern Adriatic. Finally, the fate of the ADW and its spreading into the Ionian has been investigated. Transport rates in the bottom layer across the Strait of Otranto have been estimated from long-term current-meter measurements and are related to the intensity of the ADW formation during the study period (1997-1999). Sub-inertial flow fluctuations reach as much as 1 Sv and occur during post-convection, presumably as a consequence of violent mixing processes and spreading. At longer time-scales (seasonal and

  9. Spring 2009 Water Mass Distribution, Mixing and Transport in the Southern Adriatic after a Low Production of Winter Dense Waters

    DTIC Science & Technology

    2013-05-21

    anomalies and circulation patterns, the EMT was a major climatic event in the 1990s that caused a shift in EMDW origin from cooler and fresher Adriatic...Levantine Water (MLIW) (Wust, 1961; Malanotte-Rizzoli and Hecht, 1988), coming from the Ionian sea, through Otranto Strait and circulating in the...deeper southern basin (Fig. 1). Hydrographic data and direct measurements suggest that the permanent cyclonic circulation (Southern Adriatic Gyre) of MLIW

  10. Adriatic water masses, their rates of formation and transport through the Otranto Strait

    NASA Astrophysics Data System (ADS)

    Vilibić, Ivica; Orlić, Mirko

    2002-08-01

    The paper examines dense water formation in the South Adriatic by analysing temperature, salinity and dissolved oxygen data collected during six along-Adriatic cruises carried out from the Jabuka Pit to the Otranto Strait. The least-squares tracer analysis method is applied to distinguish the fractions of the four characteristic deep, dense water masses of the Adriatic Sea. Two types of dense water generation are considered: (1) shelf type occurring during cold and dry winters in the North Adriatic and resulting in the North Adriatic dense water (NAdDW) which partially transforms to the Middle Adriatic dense water (MAdDW) on its way along the Italian shelf to the Bari Canyon, where it interacts with topography, violently mixes and sinks; and (2) deep-convection type occurring in the centre of the South Adriatic Pit, generating dense water which reaches down to 800 m, fills the bottom and enters the Ionian Sea through the Otranto Strait. Both processes are visible in the July 1976 data, as the previous winter was cold (February) and relatively dry over the whole Adriatic basin. Both types of processes can influence the bottom layer of the Otranto Strait, where the fraction of shelf-type dense water generated in the North and Middle Adriatic was occasionally observed along with the fraction of water generated by deep convection in the South Adriatic. During the non-generative period, the cyclonic South Adriatic Gyre moved more to the northwest in general, as the Levantine intermediate water (LIW) occupied southeastern part of the South Adriatic Pit. However, such behaviour was not observed in January 1980, when LIW filled much of the Adriatic, thus diminishing density gradients in the South Adriatic. By applying a simple box model of water masses, it is estimated that the decay time of the Adriatic water masses equals 26 months, whereas transport of the Adriatic deep water (ADW) in the Otranto Strait amounted to 0.34 Sv during summer 1975. In the winter 1974/75 the

  11. Dense low-salinity outflow from the Adriatic Sea under mild (2001) and strong (1999) winter conditions

    NASA Astrophysics Data System (ADS)

    Sellschopp, Jürgen; ÁLvarez, Alberto

    2003-09-01

    Quasi-synoptic temperature, salinity, and oxygen measurements in the Adriatic and northern Ionian Seas (Mediterranean Sea) during two different winter conditions are presented. In addition to the confirmation of previous knowledge about deepwater formation in the eastern Mediterranean, measurements give more insight into processes in the Adriatic Sea in winter and, especially, into the fate of the dense low-salinity water masses transported by the West Adriatic Current (WAC) and its spreading into the Ionian Sea. A mild winter season without dense water production in the shallow areas of the Adriatic Sea was encountered during a cruise in February 2001. Dense water outflow, restricted to the deeper parts of the Strait of Otranto, was nevertheless present during that mild winter and also in previous records of a cruise in autumn 1999. Thus, even in times of no deepwater production in the southern Adriatic Sea, observations reveal a continuous flow of Adriatic Deep Water (ADW) through the Strait of Otranto and downslope in the northern Ionian Sea. Strong winter conditions are represented by a cruise carried out in February 1999. At that time, cold and fresh water with density higher than that of south ADW was observed on the Italian shelf. The dense coastal current is continued around Cape Santa Maria di Leuca at the heel of the Italian boot. In the Gulf of Taranto, where the width of the shelf rapidly decreases, dense coastal water is released to depth and transformed by intrusion and mixing with ambient water. Plumes and patches with horizontal extensions smaller than distances of a station grid are resolved by towed measurements in the 200 m upper layer with a multisensor chain. Products of coastal water transformation may be found at any depth on the western slopes of the Ionian Sea. The new observations of dense water carried by the WAC and plunging down to the level of neutral buoyancy in the Gulf of Taranto seem to confirm the hypothesis that the WAC could be

  12. Least-squares tracer analysis of water masses in the South Adriatic (1967 1990)

    NASA Astrophysics Data System (ADS)

    Vilibić, Ivica; Orlić, Mirko

    2001-10-01

    The paper deals mainly with the temperature and salinity data collected during 30 cruises along the South Adriatic hydrographic section Bari-Dubrovnik but also uses data collected along the sections Palagruža Sill, Brindisi-Bar and Otranto between 1967 and 1990, most of which have never been described before. The analysis reveals the fractions of Middle Adriatic Deep Water (MADW), South Adriatic Deep Water (SADW) and Modified Levantine Intermediate Water (MLIW) computed by least-squares tracer analysis. The major feature found by analysis of the time series is the shift of water properties in the early 1980s, giving an increase in density (about 0.1 kg m -3 on average), due to exceptionally cold and dry winters over the whole Mediterranean. At the section Bari-Dubrovnik the fraction of SADW is the highest and the fractions of MADW and MLIW are the lowest during winter, because of the deep convection occurring in the South Adriatic Pit in winter, usually reaching the depth of about 600-800 m. Subsurface southeastward outflow of dense water usually occurs during spring, 4 months after the weakening of the Po River discharge and 2 months after the high surface buoyancy losses in the North Adriatic, respectively. Surface buoyancy losses occurring 6 and 8 months prior to the appearance of the subsurface outflow are in general favourable events for generation of dense water in the North Adriatic. The increase of MADW fraction at the bottom of the South Adriatic Pit lags for up to 2 years behind dense water formation in the North Adriatic. The case study of November 1989 reveals the renewal of bottom water in the South Adriatic Pit due to intrusion of MLIW, whereas in April 1987 strong mixing and sinking of extremely dense water, originating in the North Adriatic, was observed in the area of the Bari Canyon on the Italian shelf break. Near-bottom outflow of the Adriatic deep water towards the Ionian Sea was observed in the Otranto Strait in both cases. The case study of

  13. West Adriatic Coastal Water Excursions into the East Adriatic

    DTIC Science & Technology

    2009-01-15

    all of the Adriatic SYNOP stations, even during the beginning of June. All of this implies the possibility of stronger or weaker ocean transport and...which is computed as accumulated turbulent transport of momentum towards the surface, follows the wind pattern, being the strongest over the Jabuka Pit...its speed, and suppress instabilities. Cessation of the winds caused relaxation of the WAC, reduced transport , and the develop- ment of eddies and

  14. The role of water mass dynamics in controlling bacterial abundance and production in the middle Adriatic Sea.

    PubMed

    Solić, M; Krstulović, N; Vilibić, I; Kuspilić, G; Sestanović, S; Santić, D; Ordulj, M

    2008-06-01

    Month-to-month fluctuations in the abundance of bacteria and heterotrophic nanoflagellates (HNF) and bacterial production, as well as various chemical (nutrients, oxygen) and physical (salinity, temperature) parameters were analysed at a station located in the open middle Adriatic Sea during one decade (1997-2006). Being influenced by both coastal waters and open Adriatic circulation in the surface layer, and by the deep Adriatic water masses in the deep layers (100 m), this station is quite suitable for detecting the environmental changes occurring in the open Adriatic Sea with respect to the circulation of its water masses and their long-term changes and anomalies. Multivariate methods were used to identify seasonal and inter-annual changes of the investigated parameters, associating observed changes to the changes in Adriatic water masses and circulation regimes. The analyses showed that bacterial abundance and production were controlled by different water mass dynamics during 1997-2001 compared to 2002-2006 period, particularly noticeable in different seasonal patterns of biological parameters. The interplay between North Adriatic Dense Water (NAdDW) and Levantine Intermediate Water (LIW) resulted in a change in the available nutrients (NAdDW is poor in orthophosphates), and as a consequence different bacterial abundance and production. A few periods were examined in detail, such as 2004, when LIW inflow was particularly strong and was accompanied by an increase of bacterial and HNF abundances, as well as of bacterial production.

  15. An eddy resolving numerical study of the general circulation and deep-water formation in the Adriatic Sea

    NASA Astrophysics Data System (ADS)

    Mantziafou, A.; Lascaratos, A.

    2004-07-01

    General circulation and deep-water formation (DWF) processes in the Adriatic basin in a climatological year were numerically simulated in a high-resolution (1/20th of a degree) implementation of the Princeton Ocean Model (POM). The "perpetual" year atmospheric data were computed from the ECMWF Reanalysis data (1°×1°) covering the period 1979-1994. The model reproduces the main basin features of the general circulation, water mass distribution and their seasonal variability. The Adriatic Deep Water exiting through the Otranto Strait is produced with two different mechanisms inside the basin: (a) by open ocean deep convection over the Southern Adriatic Pit and Middle Adriatic Pit (b) on the continental shelf of the Northern and Middle Adriatic. The estimated contributions of both mechanisms suggest that 82% of the Adriatic Deep Water is formed inside the Southern Adriatic Pit, while all the higher density water in this water mass comes from the northern regions. The role of mesoscale eddies at the periphery of the dense-water chimney in the Southern Adriatic Pit was examined and their contribution to the lateral buoyancy flux, during the convection process, found to be small. The DWF rate at Otranto Strait is 0.28 Sv with σθ over 29.15. The sensitivity of the DWF processes to interannual variability of the buoyancy forcing and river runoff was assessed with a number of process-study numerical experiments. In these experiments the effect of an imposed "extreme" buoyancy forcing during 1 year, on the DWF rates, was to modify them during the specific year, but the effects were still present in the following normal climatological year. This shows that the DWF rates and their mass characteristics at a specific year depend not only on the atmospheric conditions prevailing that specific year but on the previous year's as well, thus leading to the concept of a "memory" of the basin.

  16. The Mediterranean deep-water kelp Laminaria rodriguezii is an endangered species in the Adriatic Sea.

    PubMed

    Žuljević, Ante; Peters, Akira F; Nikolić, Vedran; Antolić, Boris; Despalatović, Marija; Cvitković, Ivan; Isajlović, Igor; Mihanović, Hrvoje; Matijević, Slavica; Shewring, Dawn M; Canese, Simonepietro; Katsaros, Christos; Küpper, Frithjof C

    Deep-water kelps are little-known large brown algae occurring close to the lower limit of photosynthetic life in the sea. This study compares historical and recent records of the deep-water Mediterranean kelp Laminaria rodriguezii in the Adriatic Sea. Historical records include data from herbarium collections and trawling fishery expeditions in the mid-twentieth century, while recent data comprise records of the last 17 years from MEDITS expeditions, ROV surveys of historical kelp locations, benthic surveys and records by fishermen. Altogether, these findings demonstrate that the Adriatic population of L. rodriguezii has suffered a decline of more than 85 % of its historical range and is now present only around the small offshore island of Palagruža. Bottom trawling activities are presumably responsible for the disappearance elsewhere. We propose to classify L. rodriguezii as "Endangered" in the Adriatic Sea under IUCN criteria B1ab(i,iii,iv), ver 3.1. Oceanographic characteristics of the habitat suggest that besides high water transparency, presence of North Adriatic Dense Water with both strong currents and stable low temperatures of around 14 °C are essential oceanographic factors for the development of L. rodriguezii in the Central Adriatic. The origin of cold water thus differs from that at upwelling sites permitting populations of tropical deep-water kelps. The phylogenetic position of L. rodriguezii is so far unknown. DNA sequences from nuclear and cytoplasmic markers of two thalli from Croatia and the western Mediterranean confirmed that L. rodriguezii is a member of the Laminariaceae and most closely related to L. ochroleuca, L. pallida and the Brazilian deep-water kelp L. abyssalis.

  17. Tracking Bottom Waters in the Southern Adriatic Sea Applying Seismic Oceanography Techniques

    DTIC Science & Technology

    2011-10-05

    profile so the weak thermohaline reflections can be visualized 3. The Adriatic context The general circulation of the Adriatic Sea is characterized by...Reflectivity Thermohaline structures Southern Adriatic Sea ABSTRACT We present the first results from the seismic oceanography (SO) cruise ADRIASE1SMIC...where we successfully imaged thermohaline fine structures in the shallow water environment (50-150 m) of the southern Adriatic Sea during March

  18. Simulating the formation and fate of dense water in a midlatitude marginal sea during normal and warm winter conditions

    NASA Astrophysics Data System (ADS)

    Querin, Stefano; Cossarini, Gianpiero; Solidoro, Cosimo

    2013-02-01

    Dense shelf water production and the deep convection process in the Adriatic Sea are investigated, considering two case studies: the first is representative of the present climatic situation, whereas the second may be expected in a scenario characterized by mild winter conditions over the basin. Dense water production and spreading are studied using a high-resolution implementation of the Massachusetts Institute of Technology general circulation model that is initialized and forced with realistic conditions. This paper provides qualitative and quantitative information on mass transport, dense water pathways, thermohaline structures, and the mixing properties of the basin. In the northern Adriatic shelf, seawater temperature is the key element for winter dense water production because it contributes more relevantly than salinity in determining density. In the southern Adriatic Sea, a small amount of dense water that cascades directly into the pit can be formed on the narrow western shelf only during cold winter conditions. Moreover, open ocean deepwater formation occurs in the middle of the southern basin. In late winter and spring, although only when winter conditions have been sufficiently cold, northern Adriatic dense shelf water forms a subsurface stream of which the densest part rapidly sinks in the southern pit along the shelf break, whereas its lighter part flows southward and reaches the Otranto Strait. The frequent occurrence of mild winter conditions could lead to lower dense water production, with a reduced dense water flow from the Adriatic Sea to the Ionian Sea and a potential great impact on the eastern Mediterranean thermohaline circulation.

  19. Coflexip installs flexible water line in Adriatic Sea

    SciTech Connect

    Not Available

    1990-07-01

    This paper reports on the design, manufacture, transport and installation of a submarine pipe line network. The network would transport potable water from Yugoslavia's Dubroynil and Peljesac peninsula to the islands of Elafiti and Mljet, popular resort areas in the Adriatic Sea. The pipe line network consists of five separate 8-in. ID flexible lines, each 10 mi long. The pipe is made of thermoplastic tubing, a steel carcass and double crossword armor. The tubing is suitable for potable water service.

  20. The effect of strong and mild winters on the exchange between the Adriatic Sea and the Eastern Mediterranean

    NASA Astrophysics Data System (ADS)

    Sellschopp, J.; Alvarez, A.

    2003-04-01

    The Adriatic Sea has played an important role in the ventilation of the deep layers of the Eastern Mediterranean Sea also after Cretan Sea Overflow Water became dominant in Eastern Mediterranean Deep Water generation. A residual bottom current of Adriatic Deep Water is continuously leaving through the Strait of Otranto. Deep water generation and dense water transport inside the Adriatic Sea depends on the amount of cooling during the specific winter season. In a cold winter, a considerable part of Adriatic dense water flow (Sigma-0 > 29.2 kg m^-3) into the Ionian Sea is provided by the West Adriatic Current on the Italian shelf.

  1. Variability of water mass properties in the last two decades in the South Adriatic Sea with emphasis on the period 2006-2009

    NASA Astrophysics Data System (ADS)

    Cardin, Vanessa; Bensi, Manuel; Pacciaroni, Massimo

    2011-06-01

    Spatially averaged temperature and salinity profiles from individual cruises between 1990 and 2009 were analysed to outline the temporal evolution of water mass properties in the deep convection site in the South Adriatic Pit (SAP). The long-term variability in thermohaline conditions has been explained and related to a close feedback mechanism between the Ionian and the Adriatic Sea. Prominent influences of the Eastern Mediterranean Transient are manifested in changes in the vertical temperature and salinity patterns in the South Adriatic, and the whole studied period was divided into three stages according to the main thermohaline characteristics: 1990-1995, 1995-2004 and the last period from 2005 onwards. Particular attention was given to data collected during 2006-2009, which permitted us to situate the actual thermohaline properties in the context of the decadal variability. This last period was characterised by a very low production of dense water in the northern basin during 2007, while from winter 2008 high production of North Adriatic Deep Water (NAdDW) and Adriatic Deep Water (AdDW) in the northern and southern basins, respectively, was observed. Finally, we used the Optimum Multiparameter Analysis (OMP) to identify the percentages of the different water masses contained in the SAP, and this highlighted some differences between two recent periods studied (2007 and 2008) and the production of dense waters.

  2. Saw-tooth modulation of the deep-water thermohaline properties in the southern Adriatic Sea

    NASA Astrophysics Data System (ADS)

    Querin, Stefano; Bensi, Manuel; Cardin, Vanessa; Solidoro, Cosimo; Bacer, Sara; Mariotti, Laura; Stel, Fulvio; Malačič, Vlado

    2016-07-01

    In this study, we investigate the dynamics of the bottom layer of the southern Adriatic Sea (eastern Mediterranean basin) by merging experimental measurements and numerical simulations. We hypothesize that the recently observed continuous density decrease over time, which was basically related to a temperature increase, and the following sudden density rise, which was caused by the intrusion of very dense water masses (cold but relatively fresh), constitute one cycle of a general "saw-tooth" pattern: the alternation of long-lasting and almost linear density decreases (mixing phases) and sudden density increases (dense water intrusion phases). The model results, which provide a basin-scale view of the process, corroborate this theory because they satisfactorily reproduced the observed oceanographic features. We describe the almost linear density decrease in terms of local mixing fostered by the advection of flow instabilities that originate from the large-scale quasi-permanent cyclonic circulation. Conversely, diffusive processes play a minor role in determining the bottom layer thermohaline variability. The interpretation of the experimental findings, supported by the numerical simulations, suggests that similar dynamics might be observed in other basins characterized by similar bathymetric and hydrodynamic features.

  3. Estimation of the Adriatic Sea water turnover time using fallout 90Sr as a radioactive tracer

    NASA Astrophysics Data System (ADS)

    Franić, Zdenko

    2005-08-01

    Systematic, long-term measurements, starting in 1963, of 90Sr activity concentrations in sea water have been performed at four locations (cities of Rovinj, Rijeka, Split and Dubrovnik) along the Croatian coast of the Adriatic Sea. In addition, fallout samples were collected in the city of Zadar. 90Sr activity concentrations are in good correlation with the fallout activity, the coefficient of correlation being 0.72. After the nuclear moratorium on atmospheric nuclear bomb tests in 1960s, 90Sr activity concentrations in sea water exponentially dropped from 14.8 ± 2.4 Bq m -3 in 1963 to 2.0 ± 0.3 Bq m -3 in 2003. In the same period, the total annual 90Sr land surface deposit in Zadar fell by three orders of magnitude, from 713.3 Bq m -2 in 1963 to 0.4 Bq m -2 in 2003. Using strontium sea water and fallout data, a mathematical model was developed to describe the rate of change of 90Sr activity concentrations in the Adriatic Sea water and estimate its mean residence time in the Adriatic. By fitting the experimental data to a theoretically predicted curve, the mean residence time of 90Sr in the Adriatic Sea water was estimated to be approximately 3.4 ± 0.4 years, standard deviation being calculated by Monte Carlo simulations. As in physical oceanography 90Sr can be used as effective radioactive tracer of water mass transport, this value also reflects the upper limit for turnover time of the Adriatic Sea water. The turnover time of 3.4 years for the Adriatic Sea water is in reasonable agreement with the value which was estimated, by studying water flows through the Strait of Otranto, to be on the order of 1 year.

  4. Exploring the Shelf-slope Dynamics in the Adriatic Sea Using Numerical Models and Seismic Oceanography (SO)

    DTIC Science & Technology

    2013-06-02

    dynamics in the Adriatic Sea using numerical models and seismic oceanography (SO) Andrea Bergamasco, Francesco M. Falcieri, Jeffrey W. Book, Sandro...sandro.carniel@ismar.cnr.it Dense shelf waters are formed and spread in the Adriatic Sea during winter periods, which dynamics are usually...high-resolution numerical model (ROMS) results was performed in two restricted areas of the Adriatic Sea : off the Gargano promontory and off the Bari

  5. The Adriatic Sea modelling system: a nested approach

    NASA Astrophysics Data System (ADS)

    Zavatarelli, M.; Pinardi, N.

    2003-01-01

    A modelling system for the Adriatic Sea has been built within the framework of the Mediterranean Forecasting System Pilot Project. The modelling system consists of a hierarchy of three numerical models (whole Mediterranean Sea, whole Adriatic Sea, Northern Adriatic Basin) coupled among each other by simple one-way, off-line nesting techniques, to downscale the larger scale flow field to highly resolved coastal scale fields. Numerical simulations have been carried out under climatological surface forcing. Simulations were aimed to assess the effectiveness of the nesting techniques and the skill of the system to reproduce known features of the Adriatic Sea circulation phenomenology (main circulation features, dense water formation,flow at the Otranto Strait and coastal circulation characteristics over the northern Adriatic shelf), in view of the pre-operational use of the modelling system. This paper describes the modelling system setup, and discusses the simulation results for the whole Adriatic Sea and its northern basin, comparing the simulations with the observed climatological circulation characteristics. Results obtained with the northern Adriatic model are also compared with the corresponding simulations obtained with the coarser resolution Adriatic model.

  6. Using Self-Organising Maps to investigate long-term changes in deep Adriatic water patterns

    NASA Astrophysics Data System (ADS)

    Vilibić, Ivica; Mihanović, Hrvoje; Šepić, Jadranka; Matijević, Slavica

    2011-04-01

    The paper attempts to document long-term changes in deep Adriatic water patterns by applying the Self-Organising Maps (SOM) method to temperature, salinity, dissolved-oxygen content, orthophosphate and total inorganic nitrogen profiles sampled at a single deep station in the South Adriatic Pit (SAP) over a half century (1957-2009). Seasonality observed in upper layers has been removed by the least-squares fitting of the annual and semi-annual sinusoidal functions. The sensitivity of the SOM to various parameter combinations reveals the importance of temperature, salinity and dissolved oxygen for mapping different water patterns, while nutrients have less influence on quality and applicability of SOM solutions to the extraction of characteristic SAP water profiles. The quality of fit obtained for different combination of the measured parameters introduced to a SOM suggests that the incomplete combinations of input parameters increase an imperfection in the applicability of SOMs to the dataset. Two modes of long-term changes in the SAP obtained by the SOM analyses are discussed with respect to the processes that drive the variability in the area, e.g., the Adriatic-Ionian Bimodal Oscillation: where the first mode is characterised by rapid changes in the transition of SAP water masses, observed before 1980s (less adoptable by the SOMs), and the second mode is characterised by steady transitions (better adoptable by the SOMs), observed in the 1990s and the 2000s. The SOM method is found to have certain advantages when compared to other methods that have previously been used to distinguish the Adriatic water masses, as it does not depend on predefinition of water mass sources and allows for gaps in series.

  7. Effects of bora wind on physical and biogeochemical properties of stratified waters in the northern Adriatic

    NASA Astrophysics Data System (ADS)

    Boldrin, A.; Carniel, S.; Giani, M.; Marini, M.; Bernardi Aubry, F.; Campanelli, A.; Grilli, F.; Russo, A.

    2009-08-01

    Wind forcing plays a key role in controlling the water column structure and circulation in the northern Adriatic Sea. Through shipboard observations and numerical modeling, we have documented the changing of oceanographic features before, during, and after a sequence of cold northeasterly bora wind pulses that occurred during stratified conditions in late September 2002. High-resolution meteorological, hydrodynamic, and wave model outputs were related to in situ observations of hydrologic parameters, dissolved nutrients and oxygen, suspended matter biogeochemical properties, and phytoplankton. The bora intensified the southward flowing coastal current along the Italian coast, establishing a frontal system that typically exists in winter. The bora also caused complete vertical mixing to 20-25 m in the water column, an influx of warm salty water from the south along the Croatian coast, and increased resuspension and southward transport of bottom sediments for the combined effects of currents and waves. The effects on the bottom were limited to the western coastal belt, as in the deeper central part of the basin hypoxic conditions were present during the whole observing period. During the bora, the concentration of inorganic dissolved nutrients in the bottom water increased consistently with the release of nutrients from the sediments and with the mineralization processes. Resuspension of bottom layer sediment represents an important source of nutrients for the water column in this period. The higher level of nutrients was observed together with an increase in phytoplankton biomass, suggesting a potential trigger for the autumnal phytoplankton bloom in the northern Adriatic. Finally, bora events seem to be able to generate a relevant increase of nutrient export from the northern Adriatic through the intensified Adriatic western coastal current, so they could play a relevant role in the nutrient balance of the basin.

  8. Picoplankton community structure before, during and after convection event in the offshore waters of the Southern Adriatic Sea

    NASA Astrophysics Data System (ADS)

    Najdek, M.; Paliaga, P.; Šilović, T.; Batistić, M.; Garić, R.; Supić, N.; Ivančić, I.; Ljubimir, S.; Korlević, M.; Jasprica, N.; Hrustić, E.; Dupčić-Radić, I.; Blažina, M.; Orlić, S.

    2014-05-01

    This paper documents the picoplankton community's response to changes in oceanographic conditions in the period between October 2011 and September 2012 at two stations belonging to the South Adriatic Pit (SAP). The recorded data include the community's abundance, composition, prokaryotic production rates and bacterial metabolic capacity. The sampling period included an intense sea cooling with formation of exceptional, record-breaking dense water. We documented an especially intense winter convection episode that completely diluted the core of Levantine intermediate waters (LIW) in a large area encompassing the SAP's center and its margin. During this convection event the whole picoplankton community had significantly higher abundances with a recorded picoeukaryotic peak at the SAP margin. In the post-convection phase in March, prokaryotic heterotrophic production strongly increased in the entire SAP area (up to 50 times; 456.8 nM C day-1). An autotrophic biomass increase (up to 5 times; 4.86 μg L-1) and a disruption of a close correspondence between prokaryotic heterotrophic biomass production and cell replication rates were observed only in the center of the SAP, which was not under the influence of LIW. At the SAP's margin such an effect was attenuated by LIW, since the waters affected by LIW were characterized by decreased concentrations of dissolved inorganic nitrogen, decreased autotrophic biomasses, and by increased bacterial biomass production balanced with cell replication rates as well as by the domination of Synechococcus among autotrophic picoplankton. The metabolic capacity was lowest in spring when autotrophic biomass largely increased, while the highest levels found in the pre-convection phase (October 2011) suggest that the system was more oligotrophic before than after the convection event. Furthermore, we showed that metabolic capacity is a trait of bacterial community independent of environmental conditions and tightly linked to cell replication

  9. Scratching beneath the surface while coupling atmosphere, ocean and waves: Analysis of a dense water formation event

    NASA Astrophysics Data System (ADS)

    Carniel, Sandro; Benetazzo, Alvise; Bonaldo, Davide; Falcieri, Francesco M.; Miglietta, Mario Marcello; Ricchi, Antonio; Sclavo, Mauro

    2016-05-01

    Cold Air Outbreaks (CAOs) over shallow seas may lead to dense water formation episodes, enhancing water, heat, nutrient and sediment exchanges across the continental margin, with associated seabed reshaping. During winter 2012, a CAO episode characterised by exceptional intensity stroke the northern Adriatic Sea, one of the most effective cool engines driving the Mediterranean circulation, providing a paramount opportunity for an integrated investigation of dense shelf water dynamics. In the present study, we describe this event using a fully coupled modeling approach exploring the effects of mutual interactions among atmosphere, ocean currents and sea surface waves, usually not completely accounted for, in the resulting dense water formation. Whilst atmospheric fields appear to be marginally affected by coupled dynamics in the present case, implications for sea surface elevation and circulation are far from negligible. Measurements collected in the northern Adriatic Sea showed that a physically consistent description of energy exchanges between ocean and atmosphere provides an improved estimate of heat fluxes and of air and sea temperatures. In addition, the explicit inclusion of wave action within the modeling system further enhances the modulation of air-sea exchanges and the propagation of its effect along the water column, resulting in a different intensity of northern Adriatic gyres and in different water fluxes flowing through the formation basin. Through these main controls on the water volume involved in the densification process and on the intensity of momentum input and cooling, a coupled modeling strategy accounting for atmosphere-waves-currents interactions can turn out to be crucial for improving the quantification of thermohaline properties and energy content, newly formed dense water mass, and provide a better description of its migration pathways and rates of off-shelf descent.

  10. Water in dense molecular clouds

    NASA Technical Reports Server (NTRS)

    Wannier, P. G.; Kuiper, T. B. H.; Frerking, M. A.; Gulkis, S.; Pickett, H. M.; Wilson, W. J.; Pagani, L.; Lecacheux, A.; Encrenaz, P.

    1991-01-01

    The G.P. Kuiper Airborne Observatory (KAO) was used to make initial observations of the half-millimeter ground-state transition of water in seven giant molecular clouds and in two late-type stars. No significant detections were made, and the resulting upper limits are significantly below those expected from other, indirect observations and from several theoretical models. The implied interstellar H2O/CO abundance is less than 0.003 in the cores of three giant molecular clouds. This value is less than expected from cloud chemistry models and also than estimates based on HDO and H3O(+) observations.

  11. Accumulation of (210)Po in coastal waters (Gulf of Trieste, northern Adriatic Sea).

    PubMed

    Faganeli, Jadran; Falnoga, Ingrid; Benedik, Ljudmila; Jeran, Zvonka; Klun, Katja

    2016-07-20

    The total activity of (210)Po was determined by alpha-spectrometry in various samples (matrices) collected in the Gulf of Trieste (northern Adriatic Sea) where fresh water inflows, especially from the Isonzo River in the northern part, affect water quality. Observed (210)Po levels were: 1) 0.56-3.75 mBq/L in the dissolved phase (<0.45 μm) in the seawater column and local rivers, 2) 0.35-3.11 mBq/L (400-2300 Bq/kg, dry weight, dw) in suspended particulate matter (SPM, 0.45-20 μm) in the seawater column and local rivers, 3) 40 (Isonzo River) -158 Bq/kg (in a surface sediment cores collected in a NS transect in the gulf and sectioned to the depth of 20 cm) and 4) 239 (autumn) - 415 to 1800 (spring) Bq/kg (dw) in meso(zoo)plankton (>200 μm). In seawater and tributaries, up to 80% (mean 49%) of total (210)Po was found in particulate form. In sediments, slightly higher levels were encountered in the Isonzo prodelta and in the central (depocenter) part of the gulf. KD (L/kg) calculated between seawater and SPM, and seawater and sediment amounted to about 5 × 10(6) and 6 × 10(4), respectively. Lower autumn (210)Po levels can be a consequence of biological dilution by higher mesozooplankton biomass in the autumn compared to spring. Plankton fractionation revealed in general the highest levels in the >200 μm mesoplankton fraction (239-1800 Bq/kg) followed by 50-200 μm (388-996 Bq/kg) and 20-50 μm (318-810 Bq/kg) microplankton fractions. Obtained data show higher (210)Po levels in all matrices analyzed in the Gulf of Trieste compared to other Adriatic (central Adriatic) and western Mediterranean areas. The (210)Po/(210)Pb ratios in water, plankton and sediments were mostly below or around 1, while this ratio was much higher at higher trophic levels (up to about 50), reflecting a preferential bioaccumulation of (210)Po over (210)Pb. (210)Po accumulation between seawater and SPM and seawater and mesozooplankton amounted to 3.7 × 10(4) and 1.1

  12. Eutrophication in the northern Adriatic Sea: Pore water and sediment studies

    SciTech Connect

    Hammond, D.E.; Berelson, W.M. ); Giordani, P.; Langone, L.; Frignani, M.; Ravaioli, M. )

    1990-01-09

    The northern Adriatic Sea has been plagued by problems of eutrophication. This area is relatively shallow (maximum depth = 60m), becoming stratified during the summer months which inhibits oxygen transport to bottom waters. Anthropogenic nutrient loading in rivers entering the northern Adriatic (Po River being the largest) has increased nutrient input to this system and stimulated algal growth. Cores were collected for studies of pore water and solid phase chemistry at 6 stations in this region. [sup 210]Pb was used to constrain sediment accumulation rates and a range of 0-0.5 cm/yr was determined at different stations. Excess [sup 234]Th was only found in the upper 1-2 cm, suggesting that bioturbation is largely restricted to shallow depths. Pore water profiles show evidence of irrigation, and mean diffusive fluxes for oxygen, silica phosphate and ammonia are generally 20-90% of the fluxes obtained from benthic chamber measurements. This is consistent with previous work in this area in which studies of radon fluxes indicated that irrigation plays an important role in sediment-water exchange. Pore water profiles in the northern portion of the study area (near the Po River Delta) were markedly different than profiles in the south; sediments in the north are substantially more acidic and have high concentrations of dissolved iron and phosphate. From the alkalinity vs. TCO[sub 2] relationship in sediment pore waters it appears that differences in reactions involving the reduction of iron oxides and the exchange of magnesium for iron in clays are responsible for this regional difference in pore water properties. Sediments close to the Po apparently undergo more iron-magnesium exchange, while more distal sediments are limited in their ability to do so. Other pore water observations are limited in their ability to do so. Other pore water observations and trends regarding the shape of the silica profiles (which show shallow maxima) will be discussed.

  13. Climate change impacts on marine water quality: The case study of the Northern Adriatic sea.

    PubMed

    Rizzi, J; Torresan, S; Critto, A; Zabeo, A; Brigolin, D; Carniel, S; Pastres, R; Marcomini, A

    2016-01-30

    Climate change is posing additional pressures on coastal ecosystems due to variations in water biogeochemical and physico-chemical parameters (e.g., pH, salinity) leading to aquatic ecosystem degradation. With the main aim of analyzing the potential impacts of climate change on marine water quality, a Regional Risk Assessment methodology was developed and applied to coastal marine waters of the North Adriatic. It integrates the outputs of regional biogeochemical and physico-chemical models considering future climate change scenarios (i.e., years 2070 and 2100) with site-specific environmental and socio-economic indicators. Results showed that salinity and temperature will be the main drivers of changes, together with macronutrients, especially in the area of the Po' river delta. The final outputs are exposure, susceptibility and risk maps supporting the communication of the potential consequences of climate change on water quality to decision makers and stakeholders and provide a basis for the definition of adaptation and management strategies.

  14. Long-term climate variability of the Adriatic Sea thermohaline properties using an ensemble of regional ocean hindcast simulations

    NASA Astrophysics Data System (ADS)

    Dunic, Natalija; Vilibic, Ivica; Sepic, Jadranka; Sevault, Florence; Somot, Samuel; Waldman, Robin; Jorda, Gabriel

    2016-04-01

    The Adriatic Sea has a substantial impact on dynamical properties and thermohaline circulation of the Eastern Mediterranean, through a large freshwater input and dense water formation processes that drive the thermohaline circulation of the Adriatic-Ionian basin. Together with Bimodal Adriatic-Ionian Oscillation (BiOS), it represents the major driving process of interannual and decadal variations in thermohaline properties of the Adriatic Sea and Central/Eastern Mediterranean. Recent findings, extracted from the long-term observations, implicate a change in driving Adriatic climate processes, which might be important for future climate of the whole Eastern Mediterranean. The reproduction of these processes may be challenging for climate models, as occurring over limited areas and over daily timescales at the most. For that reason, an ensemble of NEMOMED regional ocean hindcast simulations with different spatial (10 and 6 km) and vertical (43 and 75 z-levels) resolutions, atmosphere (50 and 12 km resolution) and freshwater (from 8 to 43 river mouths in the basin) forcing have been analyzed, focusing on their representativeness for the Adriatic Sea dynamics. Furthermore, new Adriatic river climatology, developed recently within short-term oceanographic studies, has been imposed to the hindcast simulations with an aim to lower model biases. Half-centurial time series of temperature and salinity collected at the Palagruža Sill transect, and at the Jabuka and South Adriatic Pits known to be collectors of the Adriatic dense waters, were used for verification of models. The analyses focused on the reproduction of the Adriatic interannual and decadal variations, including their governing processes, dense water formation and BiOS for the 1980-2012 time period. Once becoming reliably reproduced, it will allow for an assessment of their importance and changes in future climate.

  15. Bathing water profile in the coastal belt of the province of Pescara (Italy, Central Adriatic Sea).

    PubMed

    Liberatore, Lolita; Murmura, Federica; Scarano, Antonio

    2015-06-15

    The quality of bathing water is fundamental, not only from an environmental point of view but also due to the economic importance of tourism. This paper examines the water profile in the coastal belt of the province of Pescara (Italy, Central Adriatic Sea) with reference to the microbiological parameters Escherichia coli and intestinal enterococci required by Directive 2006/07 of European Commission. The water quality of 15 coastal beaches was surveyed; data were produced from monitoring and controls made available by the Abruzzo Regional Environmental Prevention and Protection Agency (ARTA) and extracted and elaborated for the period of interest (2010-2013). Statistical analysis was used to confirm the aspects deduced from mean values of monitoring and control data for each stretch. The data highlight critical situations in various parts of the coast; these problems can be attributed to river pollution, mainly due to the malfunctioning of the treatment plants for urban wastewater.

  16. Tracking cold bottom water in the Gargano Peninsula and Bari Canyon regions of the Adriatic using seismic oceanography

    NASA Astrophysics Data System (ADS)

    Wood, Warren; Book, Jeffrey; Carniel, Sandro; Lindwall, Dennis; Bortoluzzi, Giovanni; Hobbs, Richard

    2010-05-01

    Tracking cold, dense bottom water from conventional ship sampling is difficult - equipment safety concerns result in incomplete sampling near the seafloor, and lateral variability can be significant. Mooring time series are poor at mapping dense water vein spatial extents and can even completely miss sampling narrow veins. The relatively new technique of seismic oceanography (SO) could potentially provide a new way of identifying and characterizing these bottom waters that is not as subject to the constraints and difficulties of present methods. Furthermore, combining SO with conventional sampling is particularly appealing for better characterization of the quick and small scales of dense water cascades and bottom trapped phenomenon.. There is a relationship between oceanic temperatures and the seismic data such that seismic images can be made to represent a quantitative measure of vertical temperature gradient through much of the water column and even very near the seafloor. The SO technique involves towing a low frequency, broadband (20-250 Hz) sound source (such as an air gun array) and a long, 600-1200 m, array of hydrophones. SO uses much lower frequencies than conventional Acoustical Oceanography (AO) techniques, and is affected by the acoustic impedance (product of sound speed and density) directly, not via proxy such as impurities or biota in the water. The sound pulses reflect off the (mostly temperature) contrasts in the water, and are recorded on the hydrophone array, creating an image of temperature gradient. Because the reflection coefficients are small, signal-enhancing techniques such as synthetic aperture (common midpoint binning) processing is required. The images generated using SO allow for the tracking of very thin (less than 10 m thick) bottom currents provided that the temperature contrast between the bottom, and overlying water is strong enough (0.3 to 1.2 degrees C, depending on acoustic noise levels) and abrupt enough (10-15 meters). The

  17. Dynamics and drivers for dense shelf water formation, migration and cascading

    NASA Astrophysics Data System (ADS)

    Bonaldo, Davide; Benetazzo, Alvise; Barbariol, Francesco; Bergamasco, Andrea; Boldrin, Alfredo; Marcello Falcieri, Francesco; Langone, Leonardo; Sclavo, Mauro; Trincardi, Fabio; Carniel, Sandro

    2015-04-01

    Dense Shelf Waters formation and their descent towards the deep ocean are generally accepted as one of the main factors driving large-scale thermohaline and biogeochemical fluxes from the continental shelf. With reference to a particularly intense event occurred in winter 2012 in the northern Adriatic Sea (namely Gulf of Venice), an epicontinental basin of the Mediterranean Sea, a set of high-resolution (1 km horizontal discretization) numerical experiments carried out by means of the COAWST (Coupled Ocean, Atmosphere Waves and Sediment Transport) modelling system allowed to explore the dynamics underlying such phenomena. The role of external factors (freshwater input, tides, and continental margin topography) was investigated as well as the mutual interactions involving atmosphere, waves and ocean circulation. The so-called North Adriatic Dense Water (NAdDW) forms in the Gulf of Venice as a consequence of the cooling and salinization of the sub-basin induced by cold air jets blowing from northeast across the Eastern Alps and Balkans. Partially recirculating in a double-gyre structure, newly formed water masses progressively leave the formation region flowing southeastwards leant on the Italian shelf. Along its path, significant fractions of NAdDW are intercepted by mid-Adriatic pits and by the continental shelf break off the Apulian coast. Whilst riverine freshwater input is crucial in preconditioning the NAdDW formation basin and controlling the intrusion of saltier waters from the south, atmosphere-wave-ocean dynamics drive the generation proper by governing air-sea heat and momentum exchanges and ocean circulation, with substantial effects on the modes of buoyancy extraction and on the extent of the water masses involved in this process. The trajectory of the dense stream leaving the northernmost basin tends to a geostrophic equilibrium determined by water mass momentum and density, which in turn reflect the interplay of the factors acting on the generation

  18. Mussels (Mytilus galloprovincialis) as a bio-indicator species in radioactivity monitoring of Eastern Adriatic coastal waters.

    PubMed

    Krmpotić, Matea; Rožmarić, Martina; Barišić, Delko

    2015-06-01

    Croatian Adriatic coastal waters are systematically monitored within the Mediterranean Mussel Watch Project using mussels (Mytilus galloprovincialis) as a bio-indicator species. The study includes determination of naturally occurring ((7)Be, (40)K, (232)Th, (226)Ra and (238)U), as well as anthropogenic (137)Cs radionuclides. Activity concentrations in dry weight of mussels' soft tissue along the Croatian Adriatic coast are presented, with spatial and seasonal variations given and discussed. Samples were collected in spring and autumn for the period between 2009 and 2013. Radionuclides were determined by gamma-ray spectrometry. Activity concentrations of (7)Be were the highest in spring periods, especially in the areas with significant fresh water discharges. Activity concentrations of (40)K did not vary significantly with season or location. (137)Cs activities were low, while (232)Th, (226)Ra and (238)U activities were mostly below the detection limit of performed gamma-spectrometric measurement.

  19. Picoplankton community structure before, during and after convection event in the offshore waters of the southern Adriatic Sea

    NASA Astrophysics Data System (ADS)

    Najdek, M.; Paliaga, P.; Šilović, T.; Batistić, M.; Garić, R.; Supić, N.; Ivančić, I.; Ljubimir, S.; Korlević, M.; Jasprica, N.; Hrustić, E.; Dupčić-Radić, I.; Blažina, M.; Orlić, S.

    2013-11-01

    This paper documents the picoplankton community's response to changes in oceanographic conditions in the period between October 2011 and September 2012 at two stations belonging to South Adriatic Pit (SAP). The recorded data include the community's abundance, composition, prokaryotic production rates and bacterial metabolic capacity. The aforementioned interval included an intense sea cooling with formation of exceptionally, record-breaking dense water. We documented an especially intense winter convection episode that completely diluted the core of Levantine intermediate waters (LIW) in a large area encompassing the SAP's center and its margin. During this convection event the whole picoplankton community had significantly higher abundances with a recorded picoeukaryotic peak at the SAP margin. In the post-convection phase in March prokaryotic heterotrophic production strongly increased in the entire SAP area (up to 50 times; 456.8 nM C day-1). The autotrophic biomass increase (up to 5 times; 4.86 μg L-1) and a disruption of a close correspondence between prokaryotic heterotrophic biomass production and cell replication rates were observed only in the center of the SAP, which was not under the influence of LIW. At the SAP's margin such an effect was attenuated by LIW, since the waters affected by LIW were characterized by decreased concentrations of dissolved inorganic nitrogen, decreased autotrophic biomasses and by increased bacterial biomass production balanced with cell replication rates as well as by the domination of Synechococcus among autotrophic picoplankton. Metabolic capacity was the lowest in spring when autotrophic biomass largely increased, while the highest levels found in the pre-convection phase (October 2011) suggests that the system was more oligotrophic before than after the convection event. Furthermore, we showed that metabolic capacity is a trait of bacterial community independent of environmental conditions and tightly linked to cell

  20. Diversity of rare and abundant bacteria in surface waters of the Southern Adriatic Sea.

    PubMed

    Quero, Grazia Marina; Luna, Gian Marco

    2014-10-01

    Bacteria are fundamental players in the functioning of the ocean, yet relatively little is known about the diversity of bacterioplankton assemblages and the factors shaping their spatial distribution. We investigated the diversity and community composition of bacterioplankton in surface waters of the Southern Adriatic sub-basin (SAd) in the Mediterranean Sea, across an environmental gradient from coastal to offshore stations. Bacterioplankton diversity was investigated using a whole-assemblage genetic fingerprinting technique (Automated Ribosomal Intergenic Spacer Analysis, ARISA) coupled with 16S rDNA amplicon pyrosequencing. The main physico-chemical variables showed clear differences between coastal and offshore stations, with the latter displaying generally higher temperature, salinity and oxygen content. Bacterioplankton richness was higher in coastal than offshore waters. Bacterial community composition (BCC) differed significantly between coastal and offshore waters, and appeared to be influenced by temperature (explaining up to 30% of variance) and by the trophic state. Pyrosequencing evidenced dominance of Alphaproteobacteria (SAR11 cluster), uncultured Gammaproteobacteria (Rhodobacteraceae) and Cyanobacteria (Synechococcus). Members of the Bacteroidetes phylum were also abundant, and accounted for 25% in the station characterized by the higher organic carbon availability. Bacterioplankton assemblages included a few dominant taxa and a very large proportion (85%) of rare (<0.1%) bacteria, the vast majority of which was unique to each sampling station. The first detailed census of bacterioplankton taxa in the SAd sub-basin, performed using next generation sequencing, indicates that assemblages are highly heterogeneous, spatially structured according to the environmental conditions, and comprise a large number of rare taxa. The high turnover diversity, particularly evident at the level of the rare taxa, suggests to direct future investigations toward larger

  1. Catalytic behaviour of dense hot water.

    PubMed

    Wu, Christine J; Fried, Laurence E; Yang, Lin H; Goldman, Nir; Bastea, Sorin

    2009-04-01

    Water is known to exhibit fascinating physical properties at high pressure and temperature. Its remarkable structural and phase complexities suggest the possibility of exotic chemical reactivity under extreme conditions, although this remains largely unstudied. Detonations of high explosives containing oxygen and hydrogen produce water at thousands of kelvin and tens of gigapascals, similar to conditions in the interiors of giant planets. These systems thus provide a unique means of elucidating the chemistry of 'extreme water'. Here, we show that water has an unexpected role in catalysing complex explosive reactions--contrary to the current view that it is simply a stable detonation product. Using first-principles atomistic simulations of the detonation of the high explosive pentaerythritol tetranitrate, we discovered that H(2)O (source), H (reducer) and OH (oxidizer) act as a dynamic team that transports oxygen between reaction centres. Our finding suggests that water may catalyse reactions in other explosives and in planetary interiors.

  2. Catalytic Behavior of Dense Hot Water

    SciTech Connect

    Wu, C J; Fried, L E; Yang, L H; Goldman, N; Bastea, S

    2008-06-05

    Water is known to exhibit fascinating physical properties at high pressures and temperatures. Its remarkable structural and phase complexity suggest the possibility of exotic chemical reactivity under extreme conditions, though this remains largely unstudied. Detonations of high explosives containing oxygen and hydrogen produce water at thousands of K and tens of GPa, similar to conditions of giant planetary interiors. These systems thus provide a unique means to elucidate the chemistry of 'extreme water'. Here we show that water plays an unexpected role in catalyzing complex explosive reactions - contrary to the current view that it is simply a stable detonation product. Using first-principles atomistic simulations of the detonation of high explosive pentaerythritol tetranitrate (PETN), we discovered that H{sub 2}O (source), H (reducer) and OH (oxidizer) act as a dynamic team that transports oxygen between reaction centers. Our finding suggests that water may catalyze reactions in other explosives and in planetary interiors.

  3. Effects of winter convection on the deep layer of the Southern Adriatic Sea in 2012

    NASA Astrophysics Data System (ADS)

    Bensi, M.; Cardin, V.; Rubino, A.; Notarstefano, G.; Poulain, P. M.

    2013-11-01

    We analyze aspects concerning the thermohaline changes observed in the near-bottom layer of the Southern Adriatic Pit (SAP), in the Eastern Mediterranean, after the arrival of abundant and exceptionally dense water (σθ > 30 kg m-3) produced in the shallow Northern Adriatic Sea during winter 2012. For this purpose, we use temperature (T), salinity (S), and current time series collected at the E2M3A deep-ocean observatory of the Southern Adriatic, and Conductivity-Temperature-Depth data obtained both in the Southern and Middle Adriatic from freely drifting profiling floats. The dense water produced in the Northern Adriatic arrived in the central and deepest part of the SAP as a series of individual pulses starting on 10 March 2012; while, a stronger and prolonged signal that significantly modified the local deep water stratification arrived after 10 April 2012. As a consequence, T and S suddenly decreased (≈0.15°C and ≈0.015), thus interrupting positive T and S bottom trends observed during the previous 5 years and producing a density increase of ≈0.02 kg m-3. Such variability has been rarely observed in the area. We ascribe its occurrence to the concomitance of exceptionally harsh and long-lasting Bora wind, scarce precipitation, and low river discharge over the Northern Adriatic during winter 2011/2012. Eventually, this newly formed AdDW reached the Strait of Otranto during July 2012. Its characteristics profoundly differed from those observed in the previous decade. Hence, a noticeable variability in structure and circulation of the abyssal layers of the Ionian basin is likely to occur in the near future.

  4. Investigating the circulation patterns of the northern Adriatic Sea with a very high resolution model.

    NASA Astrophysics Data System (ADS)

    Zavatarelli, M.; Mattia, G.; Lovato, T.

    2015-12-01

    The NEMO model was implemented on the northern Adriatic sea with an high resolution (horizontal resolution of 800 m and vertical resolution of 2 m). The model is off-line nested with a general circulation model of Mediterranean sea providing open boundary data. Hindcast simulations with high frequency atmospheric forcing and daily river runoff, were performed and analyzed in order to study the interannual variability of the circulation pattern and of the shelf dense water (Northern Adriatic dense Water, NADW) production in relation to the freshwater input and heat and wind forcing. Whenever possible, the results were validated against available observations. The simulations highlighted the large interannual variability of the circulation patterns. This is a contribution of the EU-FP7 Project "PERSEUS" (Policy oriented environmental research in the Southern European Seas)

  5. Radioactive contamination of cistern waters along the Croatian coast of the Adriatic Sea by [sup 90]Sr

    SciTech Connect

    Franic, Z.; Lokobauer, N.; Marovic, G. . Radiation Protection Unit)

    1999-07-01

    Measurements of radioactive contamination of water samples from cisterns collecting rainwater containing fission products from roofs and other surfaces have been carried out along the Croatian coast of the Adriatic sea since 1968. An exponential decline of radioactivity followed the nuclear moratorium. After the nuclear accident at Chernobyl, higher levels of [sup 137]Cs and [sup 90]Sr were detected again, with cistern waters being the only environmental samples in Croatia in which elevated [sup 90]Sr activities persisted for several years. For the pre-Chernobyl period, the observed mean residence time of [sup 90]Sr in cistern waters, estimated to be 6.2 [+-] 1.9 y, was similar to that calculated for fallout. Contrary, for the post-Chernobyl time, observed [sup 90]Sr mean residence time was calculated to be considerably shorter, reflecting the tropospheric mean residence time. The annual dose for the critical adult population received from [sup 90]Sr and [sup 137]Cs by drinking cistern water was estimated to be very small, in the 1990's less than few [micro]Sv y[sup [minus]1].

  6. Mercury speciation in the Adriatic Sea.

    PubMed

    Kotnik, Jože; Horvat, Milena; Ogrinc, Nives; Fajon, Vesna; Žagar, Dušan; Cossa, Daniel; Sprovieri, Francesca; Pirrone, Nicola

    2015-07-15

    Mercury and its speciation were studied in surface and deep waters of the Adriatic Sea. Several mercury species (i.e. DGM – dissolved gaseous Hg, RHg – reactive Hg, THg – total Hg, MeHg – monomethyl Hg and DMeHg – dimethylmercury) together with other water parameters were measured in coastal and open sea deep water profiles. THg concentrations in the water column, as well as in sediments and pore waters, were the highest in the northern, most polluted part of the Adriatic Sea as the consequence of Hg mining in Idrija and the heavy industry of northern Italy. Certain profiles in the South Adriatic Pit exhibit an increase of DGM just over the bottom due to its diffusion from sediment as a consequence of microbial and/or tectonic activity. Furthermore, a Hg mass balance for the Adriatic Sea was calculated based on measurements and literature data.

  7. Water-gas dynamics and coastal land subsidence over Chioggia Mare field, northern Adriatic Sea

    NASA Astrophysics Data System (ADS)

    Teatini, Pietro; Baú, Domenico; Gambolati, Giuseppe

    2000-09-01

    A major development programme comprising 15 gas fields of the northern Adriatic Sea has recently been submitted to the Ministry of the Environment, VIA Committee for the assessment of the environmental impact, by ENI-Agip, the Italian national oil company. One of the largest reservoirs is Chioggia Mare, located about 10 km offshore of the Venetian littoral, with a burial depth of 1000-1400 m. The planned gas production from this field is expected to impact the shoreline stability with a potential threat to the city of Venice, 25 km northwest of the center of Chioggia Mare. To evaluate the risk of anthropogenic land subsidence due to gas withdrawal, a numerical model was developed that predicts the compaction of both the gas-bearing formations and the lateral/bottom aquifer (water drive) during a 13-year producing and a 12-year post-production period, and the transference of the deep compaction to the ground surface. To address the uncertainty of a few important hydromechanical parameters, several scenarios are simulated and the most pessimistic predictions obtained. The modeling results show that at most 1 cm of land subsidence over 25 years may be expected at the city of Chioggia, whereas Venice is not subject to settlement. If aquifer drawdown is mediated by water injection, land subsidence is arrested 5 km offshore, with the Chioggia littoral zone experiencing a rebound of 0.6-0.7 cm. Résumé. Un important programme de développement portant sur 15 gisements de gaz du nord de l'Adriatique a été récemment soumis au Comité VIA pour l'évaluation de l'impact sur l'environnement du Ministère de l'Environnement, par la société ENI-Agip, la compagnie nationale pétrolière italienne. L'un des plus importants réservoirs est celui de Chioggia Mare, situé à environ 10 km au large du littoral vénitien, à une profondeur de 1000 à 1400 m. La production de gaz prévue pour ce gisement laisse envisager un impact sur la stabilité du trait de côte, avec une

  8. Blooms of the potentially toxic diatom Pseudo-nitzschia calliantha Lundholm, Moestrup & Hasle in coastal waters of the northern Adriatic Sea (Croatia)

    NASA Astrophysics Data System (ADS)

    Marić, Daniela; Ljubešić, Zrinka; Godrijan, Jelena; Viličić, Damir; Ujević, Ivana; Precali, Robert

    2011-05-01

    The genus Pseudo-nitzschia contains more than 30 species, though most of them are discernible only on the basis of ultrastructural or genetic differences. We present a taxonomic study of Pseudo-nitzschia calliantha Lundhum, Hasle & Moestrup in the coastal waters of the northern Adriatic Sea together with domoic acid (DA) measurements on natural and breeding populations of shellfish. Sampling carried out monthly at 13 stations during 2007 showed Pseudo-nitzschia species to be present with high abundances during the entire year, forming blooms in coastal waters (reaching abundances of up to 1.2 × 10 6 cells L -1) during the late summer/early autumn, when they contributed up to 70% of the whole phytoplankton community. Ultrastructural examination provided evidence that the observed blooms were formed by the potentially toxic species P. calliantha. After the P. calliantha bloom, DA was detected at 3 stations along the north-eastern Adriatic coast with concentrations ranging from 0.11 to 1.32 μg g -1 in shellfish tissue. The distribution patterns of the species were analyzed statistically in order to explain the relationships between environmental variables and population dynamics. We here report on a mass appearance of the potentially toxic P. calliantha in the coastal waters of the northern Adriatic.

  9. Topographic vorticity waves forced by Antarctic dense shelf water outflows

    NASA Astrophysics Data System (ADS)

    Marques, Gustavo M.; Padman, Laurie; Springer, Scott R.; Howard, Susan L.; Özgökmen, Tamay M.

    2014-02-01

    We use numerical simulations to investigate excitation of topographic vorticity waves (TVWs) along the Antarctic continental slope by outflows of dense shelf water through troughs. Idealized models show that wave frequency depends on the amount of stretching in the ambient fluid over the outflow and on background along-slope mean flow. Frequency is higher for steeper bottom slope, larger outflow density anomaly, and stronger westward mean flow. For weak stratification and weak westward along-slope flows typical of the Antarctic slope, wave energy propagates eastward, in the opposite direction from phase velocity. Our results are consistent with recent observations of TVWs in the southern Weddell Sea. In a realistic simulation of the Ross Sea, TVW properties are modulated on seasonal and shorter time scales as background ocean state varies. We expect these waves to affect mixing, cross-slope exchanges, and sea ice concentration in the vicinity of sources of dense water outflows.

  10. Thermohaline variability in the Adriatic and Northern Ionian Seas observed from the Argo floats during 2010-2014

    NASA Astrophysics Data System (ADS)

    Kovačević, Vedrana; Ursella, Laura; Gačić, Miroslav; Notarstefano, Giulio; Menna, Milena; Bensi, Manuel; Civitarese, Giuseppe; Poulain, Pierre-Marie

    2015-04-01

    The Adriatic Sea is the northernmost basin of the Eastern Mediterranean Sea (EMed). At its southern end, the basin communicates with the adjacent Ionian Sea through the 80 km wide and 850 m deep Strait of Otranto. Due to the river discharge in the north and due to the strong winter cooling, the Adriatic is both a dilution basin and the dense water formation region. The basin-wide circulation is cyclonic. The circulation is however, energetic also at smaller spatial and temporal scales, and several circulation cells and mesoscale features are regularly observed equally along the littoral and in the open sea. The North Adriatic Dense Water (NAdDW) formed during winter is the densest water of the whole Mediterranean Sea (up to 1060 kg/m3). It flows as a density driven bottom current from the northern shelf toward south, filling the deep layers of the middle and southern Adriatic pits. The deep open-sea area of the South Adriatic Pit (SAP, 1200 m) feels the influence of a water mass exchange through the Strait of Otranto. Specifically, it receives salty and warm surface and Levantine Intermediate Waters from the Ionian Sea. Through the open-sea winter convection that homogenizes and ventilates 400-800 m thick upper water column, this salty water contributes to the formation of the Adriatic Deep Water (AdDW, 1029.17-1029.20 kg/m3), which is not as dense as the NAdDW. Both dense waters eventually mix and spill across the sill ventilating the deep and bottom layers of the Ionian Sea, and driving the deep thermohaline cell of the EMed. Thermohaline properties of the Adriatic Sea vary at wide spatial and temporal scales, and this in turn affects the properties of its dense waters. The long-term scales are of a particular interest, as they are often associated with the biogeochemical and biotic variability such as intrusion of alien species into the Adriatic Sea and interconnection with the adjacent Ionian basin. Due to the extremely variable meteo- and climatic conditions

  11. Interannual variability of the Adriatic Sea circulation

    NASA Astrophysics Data System (ADS)

    Beg Paklar, Gordana; Sepic, Jadranka; Grbec, Branka; Dzoic, Tomislav; Kovac, Zarko; Ivatek-Sahdan, Stjepan

    2016-04-01

    The Regional Ocean Modeling System (ROMS) was implemented in order to reproduce interannual variability of the Adriatic Sea circulation. Simulations and model result analysis were performed for a three-year period from 1st January 2011 to 31st December 2013. ROMS model run was forced with realistic atmospheric fields obtained from meteorological model Aladin, climatological river discharges, tides and Mediterranean circulation imposed at the southern open boundary. Atmospheric forcing included momentum, heat and water fluxes calculated interactively from the Aladin surface fields during ROMS model simulations. Model results were compared with available CTD and ADCP measurements and discussed in the light of the climatological circulation and thermohaline properties of the Adriatic Sea and its coastal areas. Interannual variability in the Adriatic circulation is related to the prevailing atmospheric conditions, changes in the hydrological conditions and water mass exchange at the Otranto Strait. Basic features of the Adriatic circulation - basin-wide cyclonic circulation with several embedded smaller cyclonic gyres around main pits - are well reproduced by ROMS model. Modelled temperatures and salinities are within corresponding seasonal intervals, although measured profiles generally indicate stronger stratification than modelled ones. Summer circulation in 2011 with current reversal obtained along the eastern Adriatic coast was related to the sampling results of the early fish stages as well as to ARGO drifter movements. Simulated fields from the Adriatic scale model were used to prescribe the initial and open boundary conditions for the interannual simulation in the middle Adriatic coastal domain.

  12. Dynamical Crossover in Hot Dense Water: The Hydrogen Bond Role.

    PubMed

    Ranieri, Umbertoluca; Giura, Paola; Gorelli, Federico A; Santoro, Mario; Klotz, Stefan; Gillet, Philippe; Paolasini, Luigi; Koza, Michael Marek; Bove, Livia E

    2016-09-01

    We investigate the terahertz dynamics of liquid H2O as a function of pressure along the 450 K isotherm, by coupled quasielastic neutron scattering and inelastic X-ray scattering experiments. The pressure dependence of the single-molecule dynamics is anomalous in terms of both microscopic translation and rotation. In particular, the Stokes-Einstein-Debye equations are shown to be violated in hot water compressed to the GPa regime. The dynamics of the hydrogen bond network is only weakly affected by the pressure variation. The time scale of the structural relaxation driving the collective dynamics increases by a mere factor of 2 along the investigated isotherm, and the structural relaxation strength turns out to be almost pressure independent. Our results point at the persistence of the hydrogen bond network in hot dense water up to ice VII crystallization, thus questioning the long-standing perception that hydrogen bonds are broken in liquid water under the effect of compression.

  13. Eastern-Mediterranean ventilation variability during sapropel S1 formation, evaluated at two sites influenced by deep-water formation from Adriatic and Aegean Seas

    NASA Astrophysics Data System (ADS)

    Filippidi, A.; Triantaphyllou, M. V.; De Lange, G. J.

    2016-07-01

    Present-day bottom-water ventilation in the Eastern Mediterranean basin occurs through deep-water convection originating from the two marginal basins, i.e. Adriatic and Aegean Seas. In the paleo record, long periods of enhanced deep-water formation have been alternating with shorter periods of reduced deep-water formation. The latter is related mainly to low-latitude humid climate conditions and the enhanced deposition and preservation of organic-rich sediment units (sapropels). This study focuses on sedimentary archives of the most-recent sapropel S1, retrieved from two sites under the direct influence of the two deep-water formation areas. Restricted oxygen conditions have developed rapidly at the beginning of S1 deposition in the Adriatic site, but bottom-water conditions have not persistently remained anoxic during the full interval of sapropel deposition. In fact, the variability in intensity and persistence of sedimentary redox conditions at the two deep-water formation sites is shown to be related to brief episodes of climate cooling. In the Adriatic site, sapropel deposition appears to have been interrupted twice. The 8.2 ka event, only recovered at the Adria site, is characterized by gradually increasing suboxic to possibly intermittently oxic conditions and decreasing Corg fluxes, followed by an abrupt re-establishment of anoxic conditions. Another important event that disrupted sapropel S1 formation, has taken place at ca. 7.4 cal ka BP. The latter event has been recovered at both sites. In the Adriatic site it is followed by a period of sedimentary conditions that gradually change from suboxic to more permanently oxic, as deduced from the Mn/Al pattern. Using the same proxy for suboxic/oxic sedimentary redox conditions, we observe that conditions in the Aegean Sea site shift to more permanently oxic from the 7.4 ka event onwards. However, at both sites the accumulation and preservation of enhanced amounts of organic matter have continued under these

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

    NASA Astrophysics Data System (ADS)

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

    2017-01-01

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

  15. The performance of benthic indicators of ecological change in Adriatic coastal lagoons: throwing the baby with the water?

    PubMed

    Munari, C; Mistri, M

    2008-01-01

    The ecological quality of 127 stations from six Adriatic coastal lagoons was assessed using a suite of biotic indices: H', d, 1-lambda', Delta(*), Delta(+), W, AMBI, BOPA and FINE. The analysis indicated the difficulties in deriving and using the existing indices from benthic communities in highly variable environmental conditions in coastal lagoons. Different metrics rendered different results: the use of H' resulted in the classification of all stations as "Moderate/Poor/Bad", whereas BOPA classified the majority of the stations as "Good/High". Using Delta(+), most of the stations resulted as "Not anthropogenically impacted", while the W-statistics gave 82 stations as "Undisturbed" and 45 as "Moderately/Grossly disturbed". AMBI classified 55 stations as "High/Good" and 72 as "Moderate/Poor/Bad", whereas those were 32 and 95 with FINE, respectively. The latter, which was developed just for Italian coastal lagoons, was the most conservative among the indices studied. Yet, it showed the highest correlation with the species/abundance matrix. Using indices developed for coastal waters in lagoons can give the distorted indication that the water body is degraded, when it might be just a natural, low diversity, high abundance community, i.e. a lagoonal community. Moreover, the outcome of the use of a certain index has a financial dimension such that lagoons misclassified as being "poor status" will then require expensive remediation measures. For the lagoons studied, there is probably an adequate quality and quantity of benthic data available for making management decisions, but this study highlights the limits of the existing indices for lagoonal ecosystems. The challenge for the next future is to couple long term conservation of the natural environment with the highly productive activities carried out in lagoonal ecosystems.

  16. Adjacency effects in satellite radiometric products from coastal waters: a theoretical analysis for the northern Adriatic Sea.

    PubMed

    Bulgarelli, Barbara; Kiselev, Viatcheslav; Zibordi, Giuseppe

    2017-02-01

    Biases induced by land perturbations in satellite-derived water-leaving radiance are theoretically estimated for typical observation conditions in a coastal area of the northern Adriatic Sea hosting the Aqua Alta Oceanographic Tower (AAOT) validation site. Two different correction procedures are considered: not deriving (AC-1) or alternatively deriving (AC-2) the atmospheric properties from the remote sensing data. In both cases, biases due to adjacency effects largely increase by approaching the coast and with the satellite viewing angle. Conversely, the seasonal and spectral dependence of biases significantly differ between AC-1 and AC-2 schemes. For AC-1 schemes average biases are within ±5% throughout the transect at yellow-green wavelengths, but at the coast they can reach -21% and 34% at 412 and 670 nm, respectively, and exceed 100% at 865 nm. For AC-2 schemes, adjacency effects at those wavelengths from which atmospheric properties are inferred add significant perturbations. For the specific case of a correction scheme determining the atmospheric properties from the near-infrared region and by adopting a power-law spectral extrapolation of adjacency perturbations on the derived atmospheric radiance, average biases become all negative with values up to -60% and -74% at 412 and 670 nm at the coast, respectively. The seasonal trend of estimated biases at the AAOT is consistent with intra-annual variation of biases from match-ups between in situ and satellite products derived with SeaDAS from SeaWiFS and MODIS data. Nevertheless, estimated biases at blue wavelengths exceed systematic differences determined from match-up analysis. This may be explained by uncertainties and approximations in the simulation procedure, and by mechanisms of compensation introduced by the turbid water correction algorithm implemented in SeaDAS.

  17. The influence of the river inflow on the circulation and dynamics of the Adriatic and Northern Ionian Sea

    NASA Astrophysics Data System (ADS)

    Verri, Giorgia; Pinardi, Nadia; Oddo, Paolo; Ciliberti, Stefania; Coppini, Giovanni

    2014-05-01

    The aim of this study is to understand and to assess the effects of the river runoff on the circulation and dynamics of the Central Mediterranean Sea in particular regarding to the Adriatic Sea, which is known to be a dilution basin, and the Northern Ionian Sea. River mouths are sources of both momentum and buoyancy produced by the release of light fluid into a denser ambient. River inflow strongly affects the shelf area near estuaries called Regions Of Freshwater Influence, ROFIs, but it is often also a significant forcing of the large scale thermohaline circulation. The first objective is to understand how the riverine freshwater inflow affects the estuarine/antiestuarine character and the strength of the Adriatic general circulation in the meridional direction involving both the surface and the basin interior, called Meridional Overturning Circulation, MOC. A second objective is to assess how well-known processes of the Adriatic and Northern Ionian dynamics are conditioned by the river runoff (dense water formation processes, inflow/outflow boudary currents and Northern Ionian Spreading). In order to achieve our goal a three dimensional, finite difference model based on the Nucleus for European Modeling of the Ocean (NEMO) code has been implemented in the Central Mediterranean covering both the Adriatic and the Ionian Seas. Two twin experiments, respectively with and without the river inflow, have been performed spanning the period from the beginning of 1999 to the end of 2012. As far as it concerns the river runoff contribution, the model considers the estimate (via hydrological modeling and available observations) of the runoff of the major rivers flowing into the Adriatic and the Ionian Seas available from several datasets. River discharge consists of monthly climatologies for all rivers except Po, for which daily observed data have been adopted. All the rivers included in the model, 52 flowing into the Adriatic Sea and 15 into the Ionian Sea, have been

  18. Mass balance of trace metals in the Adriatic Sea

    NASA Astrophysics Data System (ADS)

    Tankéré, S. P. C.; Price, N. B.; Statham, P. J.

    2000-07-01

    A first order mass balance of six different trace metals (Mn, Fe, Pb, Zn, Cu, Ni) was presented for a 1-year period for the different compartments of the Adriatic Sea: compartment 1 (northern Adriatic Sea), compartment 2 (central Adriatic Sea and surface layer of the southern Adriatic Sea) and compartment 3 (deep water of the southern Adriatic Sea). The Adriatic Sea appeared to be a source of dissolved Cu, Mn and Fe for the Mediterranean Sea through the Strait of Otranto whereas for dissolved Zn and Pb the Adriatic Sea appeared to be a net sink. For dissolved Ni, inputs and outputs through the Strait of Otranto balanced each other. The residence times of all metals in compartment 1 were significantly shorter than that of water indicating significant removal. In compartments 2 and 3, residence times of Mn and Fe were relatively short suggesting removal from the water column whereas for the other metals their residence times were similar to that of water. Calculations of turnover times of metals with respect to different processes showed that in compartments 1 and 2, sedimentation was the main process that affected the content of the reservoirs whereas in compartment 3, the water flux exchanges played an important role for Zn, Cu and Ni. Most of the metals clearly undergo a very dynamic cycle of sedimentation/remobilization particularly in the Northern Adriatic Sea. In the northern Adriatic Sea, most of the Mn and Fe in deposited sediment were remobilized. This was related to diagenetic processes involving the utilisation and solubilisation of Mn and Fe oxides, which occur in the surface of the sediment in the northern Adriatic Sea. In the central Adriatic Sea, remobilization of Mn and Fe was less than in the northern Adriatic Sea, suggesting that diagenesis processes appear deeper in the sediment. Advective transport of sediment was a major source of metals for the deep basin. As much as 80% of the sediments in the South Adriatic Pit might be advected from the shelf

  19. CFD modeling of water spray interaction with dense gas plumes

    NASA Astrophysics Data System (ADS)

    Meroney, Robert N.

    2012-07-01

    Numerical calculations are performed to reproduce the transport and dispersion of the continuous release of dense gases over flat homogeneous surfaces with and without the mitigating influence of a downwind water curtain. Frequently such plumes are released as a result of a chemical manufacturing, storage or gas transportation accident resulting in a ground-level hazard due to gas flammability or toxicity. A field situation in which cold carbon dioxide was released upwind of water curtains (Moodie et al., 1981) was simulated using the open-source software FDS (Fire Dynamic Simulator) a full 3-d CFD model. Only water-spray enhancement of dispersion was considered; hence, no chemical removal or reactions were present or simulated. Wind-tunnel measurements for a 1:28.9 scale replication of the Moodie experiments are also compared with the 3-d CFD results. Concentration distributions, percent dilution and forced diffusion parameters were compared in scatter diagrams. Concentration field contours with and without active spray curtains are also presented.

  20. The Southern Adriatic Basin: A Key Area For The Climatic Monitoring of The Mediterranean Sea

    NASA Astrophysics Data System (ADS)

    Civitarese, G.; Gacic, M.; Saint, The

    The Southern Adriatic, the southernmost and deepest subbasin of the Adriatic Sea, is considered a major site of deep water formation and the origin of the semi-closed ther- mohaline cell in the Eastern Mediterranean. The dynamics of the area is dominated by the presence of a quasi-permanent cyclonic gyre that intensifies in the winter season creating the conditions for the production of dense and oxygenated waters that are exported to the rest of the Eastern Mediterranean through the Strait of Otranto. The at- mospheric forcing is transferred into the marine system by the winter convective water overturning, that is the key process generating new waters and triggering the biologi- cal pump. The other main forcing is the intermediate saline water advection across the Strait of Otranto, connecting the Adriatic Sea with the general basin-scale circulation of the Eastern Mediterranean. Both of them act in determining the occurrence and the magnitude of the convective events and the related biological processes. Due to the ac- tion of these forcing, the Southern Adriatic system is subject to a significant variability on temporal scale spanning from days to decades. Recent studies have demonstrated that the local thermal and haline surface forcing generates strong year-to-year varia- tions of the vertical convection and consequently of the primary production. On the other hand, the advective forcing changes the intermediate water thermohaline prop- erties as well as the nutrient content in the basin, again affecting both the vertical convection and the biological processes. The signals associated to these processes are particularly intense, and allow us to designate this relatively small basin as a suit- able field laboratory for the study of the relationships between ocean biogeochemical cycles and climate.

  1. Water conditions and geochemistry in northern Adriatic anoxia-prone areas and response of benthic faunas to oxygen deficiencies

    NASA Astrophysics Data System (ADS)

    Zuschin, Martin; Riedel, Bettina; Stachowitsch, Michael; Cermelj, Branko

    2010-05-01

    One predicted effect of global climate change, specifically global warming, is the increase in the temperatures and stratification of shallow coastal and estuarine systems. This, coupled with ongoing anthropogenic eutrophication, will exacerbate hypoxia and benthic mortalities, significantly damaging these critical marine ecosystems. These phenomena are particularly severe on sublitoral soft-bottoms such as the poorly sorted silty sands at the study site in the northern Adriatic Sea. We deployed a specially developed underwater chamber to artificially induce anoxia in situ. Our Experimental Anoxia Generating Unit (EAGU) is a large plexiglass chamber that combines a digital camera with oxygen/hydrogen sulphide/pH sensors along with flashes and battery packs. The unit can be deployed for up to five days to autonomously generate oxygen crises and quantify both physico-chemical parameters and benthic responses. The system is initially positioned in an "open" configuration (open-sided aluminium frame) over the benthic fauna ("control" experiment). After 24 h the EAGU is switched to its "closed" configuration (plexiglass enclosure) and repositioned over the same assemblage. In this contribution, we focus on the natural oxygen content, temperature and pH of bottom waters during summer, the course of oxygen decrease during our experiments and the onset of H2S development. Oxygen content of the bottom water, a few centimetres above the sediment-water interface, ranges from ~3.5-8 but is mostly between 4-6 ml l-1 during July to September of the study periods (2005 and 2006) and decreases to zero within ~1-3 days after initiation of our experiments. In parallel, H2S starts to develop at the onset of anoxia. Water temperatures at the bottom were stable during experiments and ranged from 18.5°C to 21.4°C, but pH decreased from 8.3 to 8.1 at the beginning to 7.9 to 7.7 at the end of the experiments. Sediment profiling indicates that the diffusive benthic boundary layer is

  2. Mediterranean shelf-edge muddy contourites: examples from the Gela and South Adriatic basins

    NASA Astrophysics Data System (ADS)

    Verdicchio, Giuseppe; Trincardi, Fabio

    2008-06-01

    We present new evidence of shallow-water muddy contourite drifts at two distinct locations in the central Mediterranean characterized by a relatively deep shelf edge (between 170 and 300 m below sea level): the south-eastern Adriatic margin and the north-western Sicily Channel. The growth of these shelf-edge contourite drifts is ascribed to the long-term impact of the Mediterranean themohaline circulation. The Levantine Intermediate Water flows continuously, with annual or inter-annual variations, and affects the shelf edge and the upper slope in both study areas. In addition, the SW Adriatic margin is impinged by the seasonally modulated off-shelf cascading of North Adriatic Dense Water. This water mass has formed ever since the large Adriatic continental shelf was drowned by the post-glacial sea-level rise. It energetically sweeps the entire slope from the shelf edge to the deep basin. These bottom currents flow parallel or oblique to the depth contours, and are laterally constricted along markedly erosional moats aligned parallel to the shelf edge where they increase in flow velocity. The internal geometry and growth patterns of the shelf-edge contourites reflect changes in oceanographic setting affecting the whole Mediterranean Sea. In particular, seismic correlation with published sediment cores documents that these deposits are actively growing and migrating during the present interglacial, implying an enhancement in bottom-water formation during intervals of relative sea-level rise and highstand. Regardless of the specific mechanisms of formation, sediment drifts in both study areas have been affected by widespread thin-skinned mass-wasting events during post-glacial times. Repeated mass-transport processes have affected in particular the downslope flank of the shelf-edge contourite drifts, indicating that these muddy deposits are prone to failure during, or soon after, their deposition.

  3. Adriatic Mesoscale Experiment (AMEX)

    DTIC Science & Technology

    2002-09-30

    in the Tyrrhenian and Adriatic Seas . Details of data format and data telemetry were decided with the drifter manufacturers to guarantee high-quality...2002 to August 2003 as predicted by the statistical model. 2) The CODE drifters equipped with GPS receivers tested in the Tyrrhenian and Adriatic Seas ... Tyrrhenian Sea . TRANSITIONS This program will set up a new methodology using drifters, high-frequency coastal radars and remote sensing to study the

  4. Comments on “Cascades of dense water around the world ocean”

    NASA Astrophysics Data System (ADS)

    Durrieu de Madron, X.; Zervakis, V.; Theocharis, A.; Georgopoulos, D.

    2005-01-01

    Evidences of temperature-controlled dense water cascading off the Gulf of Lion shelf, in the northwestern Mediterranean, and several Aegean shelves in the northeastern Mediterranean are reported. Together with the Adiatic shelf, already listed by Ivanov, Shapiro, Huthnance, Aleynik, & Golovin (2004), these zones represent the major coastal areas of the Mediterranean Sea where dense water is produced.

  5. Role of prokaryotic biomasses and activities in carbon and phosphorus cycles at a coastal, thermohaline front and in offshore waters (Gulf of Manfredonia, Southern Adriatic Sea).

    PubMed

    Monticelli, L S; Caruso, G; Decembrini, F; Caroppo, C; Fiesoletti, F

    2014-04-01

    The Western areas of the Adriatic Sea are subjected to inputs of inorganic nutrients and organic matter that can modify the trophic status of the waters and consequently, the microbiological processes involved in the carbon and phosphorus biogeochemical cycles, particularly in shallow coastal environments. To explore this topic, a survey was carried out during the spring of 2003 in a particular hydrodynamic area of the Gulf of Manfredonia, where the potential (P) and real (R) rates of four different microbial exoenzymatic activities (EEA) (α [αG] and ß glucosidases [ßG], leucine aminopeptidase [LAP], and alkaline phosphatase [AP]) as well as the P and R rates of prokaryotic heterotrophic production (PHP), AP as well as the P and R rates of PHP, primary production (PPnet), the prokaryotic and phototrophic stocks and basic hydrological parameters were examined. Three different water masses were found, with a thermohaline front (THF) being detected between the warmer and less saline coastal waters and colder and saltier offshore Adriatic waters. Under the general oligotrophic conditions of the entire Gulf, a decreasing gradient from the coastal toward the offshore areas was detected, with PHP, PPnet, stocks and EEA (αG, ßG, AP) being directly correlated with the temperature and inversely correlated with the salinity, whereas opposite relationships were observed for LAP activity. No enhancement of microbiological activities or stocks was observed at the THF. The use of P or R rates of microbiological activities, which decrease particularly for EEA, could result in discrepancies in interpreting the efficiency of several metabolic processes.

  6. Water-level oscillations in the Adriatic Sea as coherent self-oscillations inferred by independent component analysis

    NASA Astrophysics Data System (ADS)

    Capuano, P.; De Lauro, E.; De Martino, S.; Falanga, M.

    2011-12-01

    We analyze tide gauge records at four stations of the ISPRA network located in the Adriatic Sea basin (Eastern Italy), namely, going from North to South: Trieste, Ancona, Ortona and Otranto. We use linear and nonlinear methods in the frequency and time domains, including spectral and Independent Component Analysis (ICA), inter-times occurrence, and phase space embedding dimension evaluation. We show that four tidal constituents can be extracted by ICA and interpreted as coherent self-sustained oscillations. Finally, we show that these constituents can be reproduced by adopting a simple nonlinear oscillatory model that generalizes classical Andronov oscillator with the inclusion of a time dependent pumping.

  7. Bacterial diversity in the South Adriatic Sea during a strong, deep winter convection year.

    PubMed

    Korlević, M; Pop Ristova, P; Garić, R; Amann, R; Orlić, S

    2015-03-01

    The South Adriatic Sea is the deepest part of the Adriatic Sea and represents a key area for both the Adriatic Sea and the deep eastern Mediterranean. It has a role in dense water formation for the eastern Mediterranean deep circulation cell, and it represents an entry point for water masses originating from the Ionian Sea. The biodiversity and seasonality of bacterial picoplankton before, during, and after deep winter convection in the oligotrophic South Adriatic waters were assessed by combining comparative 16S rRNA sequence analysis and catalyzed reporter deposition-fluorescence in situ hybridization (CARD-FISH). The picoplankton communities reached their maximum abundance in the spring euphotic zone when the maximum value of the chlorophyll a in response to deep winter convection was recorded. The communities were dominated by Bacteria, while Archaea were a minor constituent. A seasonality of bacterial richness and diversity was observed, with minimum values occurring during the winter convection and spring postconvection periods and maximum values occurring under summer stratified conditions. The SAR11 clade was the main constituent of the bacterial communities and reached the maximum abundance in the euphotic zone in spring after the convection episode. Cyanobacteria were the second most abundant group, and their abundance strongly depended on the convection event, when minimal cyanobacterial abundance was observed. In spring and autumn, the euphotic zone was characterized by Bacteroidetes and Gammaproteobacteria. Bacteroidetes clades NS2b, NS4, and NS5 and the gammaproteobacterial SAR86 clade were detected to co-occur with phytoplankton blooms. The SAR324, SAR202, and SAR406 clades were present in the deep layer, exhibiting different seasonal variations in abundance. Overall, our data demonstrate that the abundances of particular bacterial clades and the overall bacterial richness and diversity are greatly impacted by strong winter convection.

  8. Bacterial Diversity in the South Adriatic Sea during a Strong, Deep Winter Convection Year

    PubMed Central

    Korlević, M.; Pop Ristova, P.; Garić, R.; Amann, R.

    2014-01-01

    The South Adriatic Sea is the deepest part of the Adriatic Sea and represents a key area for both the Adriatic Sea and the deep eastern Mediterranean. It has a role in dense water formation for the eastern Mediterranean deep circulation cell, and it represents an entry point for water masses originating from the Ionian Sea. The biodiversity and seasonality of bacterial picoplankton before, during, and after deep winter convection in the oligotrophic South Adriatic waters were assessed by combining comparative 16S rRNA sequence analysis and catalyzed reporter deposition-fluorescence in situ hybridization (CARD-FISH). The picoplankton communities reached their maximum abundance in the spring euphotic zone when the maximum value of the chlorophyll a in response to deep winter convection was recorded. The communities were dominated by Bacteria, while Archaea were a minor constituent. A seasonality of bacterial richness and diversity was observed, with minimum values occurring during the winter convection and spring postconvection periods and maximum values occurring under summer stratified conditions. The SAR11 clade was the main constituent of the bacterial communities and reached the maximum abundance in the euphotic zone in spring after the convection episode. Cyanobacteria were the second most abundant group, and their abundance strongly depended on the convection event, when minimal cyanobacterial abundance was observed. In spring and autumn, the euphotic zone was characterized by Bacteroidetes and Gammaproteobacteria. Bacteroidetes clades NS2b, NS4, and NS5 and the gammaproteobacterial SAR86 clade were detected to co-occur with phytoplankton blooms. The SAR324, SAR202, and SAR406 clades were present in the deep layer, exhibiting different seasonal variations in abundance. Overall, our data demonstrate that the abundances of particular bacterial clades and the overall bacterial richness and diversity are greatly impacted by strong winter convection. PMID:25548042

  9. Role of dense shelf water cascading in the transfer of organochlorine compounds to open marine waters.

    PubMed

    Salvadó, Joan A; Grimalt, Joan O; López, Jordi F; Palanques, Albert; Heussner, Serge; Pasqual, Catalina; Sanchez-Vidal, Anna; Canals, Miquel

    2012-03-06

    Settling particles were collected by an array of sediment trap moorings deployed along the Cap de Creus (CCC) and Lacaze-Duthiers (LDC) submarine canyons and on the adjacent southern open slope (SOS) between October 2005 and October 2006. This array collected particles during common settling processes and particles transferred to deep waters by dense shelf water cascading (DSWC). Polychlorobiphenyls (PCBs), dichlorodiphenyltrichloroethane and its metabolites (DDTs), chlorobenzenes (CBzs)--pentachlorobenzene and hexachlorobenzene--and hexachlorocyclohexanes were analyzed in all samples. The results show much higher settling fluxes of these compounds during DSWC than during common sedimentation processes. The area of highest deposition was located between 1000 and 1500 m depth and extended along the canyons and outside them showing their channelling effects but also overflows of dense shelf water from these canyons. Higher fluxes were observed near the bottom (30 m above bottom; mab) than at intermediate waters (500 mab) which is consistent with the formation and sinking of dense water close to the continental shelf and main displacement through the slope by the bottom. DSWC involved the highest settling fluxes of these compounds ever described in marine continental slopes and pelagic areas, e.g., peak values of PCBs (960 ng · m(-2) · d(-1)), DDTs (2900 ng · m(-2) · d(-1)), CBzs (340 ng · m(-2) · d(-1)) and lindane (180 ng · m(-2) · d(-1)).

  10. A tri-modular model for the computation of the meteorological and oceanographic fields in the Adriatic Sea

    SciTech Connect

    Lionello, P.; Pernigotti, D.; Zampato, L.; Bergamasco, A.; Buzzi, A.; Malguzzi, P.

    1994-12-31

    The purpose of this research program is the construction of the modelling framework to describe and predict the development of the sea and of the atmosphere in the Adriatic region. There are two time scales that are considered: the medium range time scale of the weather-surge-oceanwave forecast and the interseasonal time scale of the thermohaline circulation in the Adriatic Sea. The phenomenology associated with the medium range is represented by the intense storms that take place in the Adriatic Sea, in spite of its relatively small extension, when the presence of a pressure minimum over Italy generates an intense Scirocco wind which, channeled by the mountain ridges surrounding the basin, blows along its whole length. Because of the long fetch, approximately 1,000 Km., this situation produces high ocean waves and the storm surge that is associated with the flooding of Venice. The interseasonal phenomenology is represented by the formation of dense water in the Northern part of the basin during winter. This is presumably caused by Bora, a strong South-Westerly wind, cold and dry, which produces cooling and evaporation in the shallow water coastal region of the Northern Adriatic. The complex orography surrounding the Adriatic and the short duration of this phenomena require a model framework capable of high space and time resolution on a limited area. This is the motivation for addressing these issues in a coupled model framework consisting of a limited area atmospheric circulation model, an ocean circulation model, and a ocean wave model with high resolution both in space and time.

  11. The Po river water from the Alps to the Adriatic Sea (Italy): new insights from geochemical and isotopic (δ(18)O-δD) data.

    PubMed

    Marchina, Chiara; Bianchini, Gianluca; Natali, Claudio; Pennisi, Maddalena; Colombani, Nicolò; Tassinari, Renzo; Knoeller, Kay

    2015-04-01

    Although the Po river is the most important fluvial system of Northern Italy, the systematic geochemical and isotopic investigations of its water are rare and were never reported for the whole basin. The present contribution aims to fill this knowledge gap, reporting a comprehensive data set including oxygen and hydrogen stable isotopes as well as major and trace element concentration of dissolved species for 54 Po river water samples, mainly collected in different hydrological conditions (peak discharge in April, drought in August) at increasing distance from the source, i.e., from the upper part of the catchment to the terminal (deltaic) part of the river at the confluence with the Adriatic Sea. The isotopic compositions demonstrate that the predominant part of the runoff derives from the Alpine sector of the catchment through important tributaries such as the Dora Baltea, Ticino, Adda, and Tanaro rivers, whereas the contribution from the Apennines tributaries is less important. The geochemical and isotopic compositions show that the Po river water attains a homogeneous composition at ca. 100 km from the source. The average composition is characterized by δ(18)O -9.8‰, δD -66.2‰, total dissolved solid (TDS) 268 mg/L, and chloride 17 mg/L and by a general Ca-HCO3 hydrochemical facies, which is maintained for most of the river stream, only varying in the terminal part where the river is diverted in a complex deltaic system affected by more significant evaporation and mixing with saline water evidenced by higher TDS and chloride content (up to 8198 and 4197 mg/L, respectively). Geochemical and isotopic maps have been drawn to visualize spatial gradients, which reflect the evolution of the river water composition at progressive distance from the source; more detailed maps were focused on the deltaic part in order to visualize the processes occurring in the transitional zone toward the Adriatic Sea. The data also highlight anthropogenic contributions, mainly

  12. Geochemistry of the Adige River water from the Eastern Alps to the Adriatic Sea (Italy): evidences for distinct hydrological components and water-rock interactions.

    PubMed

    Natali, C; Bianchini, G; Marchina, C; Knöller, K

    2016-06-01

    The Adige River flows from the Eastern Alps to the Adriatic Sea and the understanding of its fluvial dynamics can be improved by geochemical and O-H isotopic investigation. The most negative isotopic compositions are recorded close to the source (δ(18)O between -14.1 and -13.8 ‰, δD between -100.3 and -97.0 ‰), and δD and δ(18)O values generally increase downstream through the upper part (UP, the mountainous sector), stabilizing along the lower part (LP, the alluvial plain) of the river with δ(18)O between -12.4 and -11.8 ‰, δD between -86.9 and -83.7 ‰. The isotopic variations along the stream path (δ(18)O-δD vs distance from the source) depict subparallel distributions for all the investigated periods, with less negative values recorded in winter. Total dissolved solids (TDS) concentration shows the lowest value (<100 mg/l) at the river source, jumping to 310 mg/l at the Rio Ram inflow, then decreasing down to the Isarco River confluence; from here, we observed an increase toward the river mouth, with different values in the distinct sampling periods. The lowest values (140-170 mg/l) were recorded during high discharge in spring, whereas higher TDS values (up to 250 mg/l) were recorded during winter low flow conditions. Extreme TDS values were observed in the estuarine samples (up to 450 mg/l), as result of mixing with seawater. The results allow for the identification of distinct water end-members: glacio-nival component(s) characterized by the most negative isotopic composition and extremely low TDS, a rainfall component characterized by intermediate isotopic and elemental composition and groundwater characterized by the less negative isotopic composition and comparatively higher TDS. An additional component is represented by seawater, which is recorded at the lowest reach of the river during drought periods. These contributions variously mix along the stream path in the distinct hydrological periods, and the presented data are a

  13. Simulations of densely-packed cloth motion in water

    NASA Astrophysics Data System (ADS)

    Akcabay, Deniz T.

    2005-11-01

    Fluid-structure simulations of densely-packed immersed fabric model the clothes washing process. We have modified the Immersed Boundary Method (Peskin 1977) to handle the known but complex geometry of the washing machine and agitator as well as the unknown cloth structure immersed in the fluid. Extending the technique to three-dimensions has required improved computational efficiency and causes geometric singularities when cloth that is not sufficiently extensible bends in two directions. We present some preliminary comparisons to primarily two-dimensional experiments in the dilute cloth limit. Computational difficulties caused by cloth permeability and bending stiffness will be discussed.

  14. Internal Tidal Hydrodynamics and Ambient Characteristics of the Adriatic (ITHACA)

    DTIC Science & Technology

    2006-12-31

    which would enable propagation characteristics of internal waves to be determined, not just their amplitudes. Attention is also paid to the way changes of...respectively. The bathymetry of the Adriatic Sea is also shown. 5 The measuring sites were selected so as to capture gradual changes from coastal to...water types within the Adriatic is considerable in space and also significant seasonal and inter-annual changes occur in time. The investigated area

  15. Sediment dynamics in the Adriatic Sea investigated with coupled models

    USGS Publications Warehouse

    Sherwood, Christopher R.; Book, Jeffrey W.; Carniel, Sandro; Cavaleri, Luigi; Chiggiato, Jacopo; Das, Himangshu; Doyle, James D.; Harris, Courtney K.; Niedoroda, Alan W.; Perkins, Henry; Poulain, Pierre-Marie; Pullen, Julie; Reed, Christopher W.; Russo, Aniello; Sclavo, Mauro; Signell, Richard P.; Traykovski, Peter A.; Warner, John C.

    2004-01-01

    Several large research programs focused on the Adriatic Sea in winter 2002-2003, making it an exciting place for sediment dynamics modelers (Figure 1). Investigations of atmospheric forcing and oceanic response (including wave generation and propagation, water-mass formation, stratification, and circulation), suspended material, bottom boundary layer dynamics, bottom sediment, and small-scale stratigraphy were performed by European and North American researchers participating in several projects. The goal of EuroSTRATAFORM researchers is to improve our ability to understand and simulate the physical processes that deliver sediment to the marine environment and generate stratigraphic signatures. Scientists involved in the Po and Apennine Sediment Transport and Accumulation (PASTA) experiment benefited from other major research programs including ACE (Adriatic Circulation Experiment), DOLCE VITA (Dynamics of Localized Currents and Eddy Variability in the Adriatic), EACE (the Croatian East Adriatic Circulation Experiment project), WISE (West Istria Experiment), and ADRICOSM (Italian nowcasting and forecasting) studies.

  16. Water as a dense icelike component in silicate glasses

    PubMed

    Richet; Polian

    1998-07-17

    Density and Brillouin-scattering measurements of hydrous andesite glasses at ambient conditions showed that dissolved water has a concentration-independent partial molar volume of 12 +/- 0.5 cubic centimeters per mole and a bulk modulus of 18 +/- 3 gigapascals. Dissolved as hydroxyl ions or as molecular water, water has volume properties similar to those of ice VII, the densest form of ice. These properties point to hydrogen bonding as an important factor in water dissolution, and they indicate that changes of water speciation are driven by the entropy and not by the volume of the system. Water in a concentration greater than 1 percent by weight also causes a marked decrease of the shear modulus of the glass.

  17. Shaping of the Southern Adriatic Continental Margin Through Widespread Mass Wasting and Bottom Currents

    NASA Astrophysics Data System (ADS)

    Trincardi, F.; Cattaneo, A.; Correggiari, A.; Verdicchio, G.; Tobi, T.

    2003-12-01

    New TOBI seafloor images and VHR Chirp sonar profiles reveal widespread collapsing of the South Adriatic continental slope including: multiple overlapping slide scars affecting more than 100 km of Pleistocene regressive shelf-margin deposits below the shelf edge, extensive blocky slides on the lower slope (block sizes up to 200 x 500 m), and a basin wide acoustically-transparent deposit up to 40 m thick, buried under a late-Pleistocene-Holocene mud section, in water depths greater than 1000 m. Lateral variations in internal geometry and seafloor morphology likely reflects along margin differences in sediment composition and thickness of the mass-transport deposits and variable run outs (up to 40 km). Preliminary correlation to published cores in the area indicates that the main mass transport deposit reached the basin floor during the Last Glacial Maximum, but younger failures of smaller size may have affected the slope in more recent times. The new data show that the entire slope area is swept by bottom currents generating furrowed areas up to several tens of km2 in extent, moats on the downdrift side of seafloor irregularities (slide blocks) and preferential sediment deposition on the inferred updrift side, and growth of upslope-migrating sediment waves. In particular, two fields of sediment waves can be mapped in water depths of 400-600 and 1000 m. The former may reflect the activity of the Levantine Intermediate Waters, while the latter may be linked to the downslope flow of the Northern Adriatic Dense Waters. Future work will focus on the definition of intervals of growth vs quiescence of the sediment waves, their possible relation to paleoceanographic reconfigurations, and their interplay with seafloor irregularities dictated by slope instability. A smaller-scale possibly comparable interaction of seafloor morphology generated by sediment deformation and differential deposition of muddy deposits on the shelf emphasizes the importance of bottom

  18. Dense water plumes modulate richness and productivity of deep sea microbes.

    PubMed

    Luna, Gian Marco; Chiggiato, Jacopo; Quero, Grazia Marina; Schroeder, Katrin; Bongiorni, Lucia; Kalenitchenko, Dimitri; Galand, Pierre E

    2016-12-01

    Growing evidence indicates that dense water formation and flow over the continental shelf is a globally relevant oceanographic process, potentially affecting microbial assemblages down to the deep ocean. However, the extent and consequences of this influence have yet to be investigated. Here it is shown that dense water propagation to the deep ocean increases the abundance of prokaryotic plankton, and stimulates carbon production and organic matter degradation rates. Dense waters spilling off the shelf modifies community composition of deep sea microbial assemblages, leading to the increased relevance of taxa likely originating from the sea surface and the seafloor. This phenomenon can be explained by a combination of factors that interplay during the dense waters propagation, such as the transport of surface microbes to the ocean floor (delivering in our site 0.1 megatons of C), the stimulation of microbial metabolism due to increased ventilation and nutrients availability, the sediment re-suspension, and the mixing with ambient waters along the path. Thus, these results highlight a hitherto unidentified role for dense currents flowing over continental shelves in influencing deep sea microbes. In light of climate projections, this process will affect significantly the microbial functioning and biogeochemical cycling of large sectors of the ocean interior.

  19. Seasonal variations of selected herbicides and related metabolites in water, sediment, seaweed and clams in the Sacca di Goro coastal lagoon (Northern Adriatic).

    PubMed

    Carafa, R; Wollgast, J; Canuti, E; Ligthart, J; Dueri, S; Hanke, G; Eisenreich, S J; Viaroli, P; Zaldívar, J M

    2007-11-01

    This study assesses the status of Sacca di Goro coastal lagoon (Northern Adriatic, Italy) with respect to watershed pollution. Because 80% of its watershed is devoted to agriculture, plant protection products and their metabolites were found in the water column, sediments (the upper 0-15 cm layer), macroalgae (Ulva rigida) and clams (Tapes philippinarum). Five seasonal sampling campaigns were performed from May 2004 to April 2005 and concentrations measured in five stations in the lagoon and six in the watershed. Relatively high concentrations of the s-triazine - terbuthylazine -, urea herbicides - diuron - and alachlor were detected through the year mainly at stations directly influenced by the Po di Volano inflow. The concentrations of products in use follow a clear seasonal pattern with spring peaks. This pattern is also visible in the sediments as well as in biota. Among metabolites, hydroxylated compounds prevailed, often with concentrations greater than those of the parent compounds. For the most part of the year, the concentrations in biota were close to detection limits, with concentration peaks in spring.

  20. Barotropic and baroclinic currents in the Strait of Otranto (southern Adriatic Sea)

    NASA Astrophysics Data System (ADS)

    Salusti, Ettore; Serravall, Roberta

    2002-01-01

    In this note the winter presence of a tongue of cold water turning around the Apulia Peninsula, in Southern Adriatic Sea, is analyzed. Autumn and winter satellite thermal images indeed show that often cold water masses occupying the western part of the Strait of Otranto, where the bottom depth is about 800m, tend to flow clockwise apparently following the isobaths around Cape S. Maria di Leuca and finally intrude into the Gulf of Taranto. These images are here compared with CTD casts and current meter observations made during the same period, and also with some drifter surface measurements. A deepening of the surface current, and its peculiar locking into a current of Mediterranean Dense Water flowing geo strophically over the sea bottom, is also discussed as a kind of barotropic reconstruction for these clearly baroclinic flows. Theoretical considerations allow to gain some insight into these currents and their potential vorticity evolution.

  1. Thermohaline variability and mesoscale activities observed at the E2M3A deep site in the south Adriatic Sea

    NASA Astrophysics Data System (ADS)

    Bensi, M.; Cardin, V.; Gačić, M.

    2012-04-01

    The south Adriatic Sea is recognized as a dense water formation site which is able to oxygenate the deep layer of the whole eastern Mediterranean Sea. The entrance of salty water from the Ionian Sea represents a preconditioning factor for the deep convection which can occur during winters characterized by particularly vigorous air-sea heat exchanges. Continuous sampling measurements are strictly essential to better understand the deep convection. For that reason, the south Adriatic Sea has been constantly monitored by means of the E2M3A deep mooring site located in its central part (Latitude 41° 50' N, Longitude 17° 45' E, maximum depth 1250m) since 2006. Temperature, salinity and currents time series at the E2M3A site from 2006 till 2010 are analyzed. They represent currently the longest timeseries available for this region. Moreover, their integration with data obtained from several oceanographic cruises provides the necessary spatial distribution of the thermohaline properties in the study area. Here we report on the abrupt temperature and salinity decrease particularly evident down to 600m depth from March 2008 on. In fact, the intermediate layer shows a maximum temperature and salinity decrease of ~0.3°C and ~0.06 respectively, clearly evident after each severe winter. The bottom layer (~1200m) shows an opposite behaviour: it suffered an unforeseen and continous temperature and salinity increase (linear trend of ~0.05 °C y-1 and ~0.004 psu y-1respectively) during the whole observational period. The results show a strong relationship between the recently discovered variability of the Ionian surface circulation (Gačić et al. 2010) and the thermohaline variability observed in the south Adriatic. In particular, we demonstrate here the role of the winter convection in trasferring fresher surface waters towards deeper layers triggering salt content changes in the Adriatic. The intrusion of fresher water at the depth of about 700-800m noticed in the mooring

  2. Investigation of model capability in capturing vertical hydrodynamic coastal processes: a case study in the north Adriatic Sea

    NASA Astrophysics Data System (ADS)

    McKiver, W. J.; Sannino, G.; Braga, F.; Bellafiore, D.

    2016-01-01

    In this work we consider a numerical study of hydrodynamics in the coastal zone using two different models, SHYFEM (shallow water hydrodynamic finite element model) and MITgcm (Massachusetts Institute of Technology general circulation model), to assess their capability to capture the main processes. We focus on the north Adriatic Sea during a strong dense water event that occurred at the beginning of 2012. This serves as an interesting test case to examine both the models strengths and weaknesses, while giving an opportunity to understand how these events affect coastal processes, like upwelling and downwelling, and how they interact with estuarine dynamics. Using the models we examine the impact of setup, surface and lateral boundary treatment, resolution and mixing schemes, as well as assessing the importance of nonhydrostatic dynamics in coastal processes. Both models are able to capture the dense water event, though each displays biases in different regions. The models show large differences in the reproduction of surface patterns, identifying the choice of suitable bulk formulas as a central point for the correct simulation of the thermohaline structure of the coastal zone. Moreover, the different approaches in treating lateral freshwater sources affect the vertical coastal stratification. The results indicate the importance of having high horizontal resolution in the coastal zone, specifically in close proximity to river inputs, in order to reproduce the effect of the complex coastal morphology on the hydrodynamics. A lower resolution offshore is acceptable for the reproduction of the dense water event, even if specific vortical structures are missed. Finally, it is found that nonhydrostatic processes are of little importance for the reproduction of dense water formation in the shelf of the north Adriatic Sea.

  3. Seismicity of the Adriatic microplate

    USGS Publications Warehouse

    Console, R.; Di, Giovambattista R.; Favali, P.; Presgrave, B.W.; Smriglio, G.

    1993-01-01

    The Adriatic microplate was previously considered to be a unique block, tectonically active only along its margins. The seismic sequences that took place in the basin from 1986 to 1990 give new information about the geodynamics of this area. Three subsets of well recorded events were relocated by the joint hypocentre determination technique. On the whole, this seismic activity was concentrated in a belt crossing the southern Adriatic sea around latitude 42??, in connection with regional E-W fault systems. Some features of this seismicity, similar to those observed in other well known active margins of the Adriatic plate, support a model of a southern Adriatic lithospheric block, detached from the Northern one. Other geophysical information provides evidence of a transitional zone at the same latitude. ?? 1993.

  4. An experiment to determine drilling water imbibition by in situ densely welded tuff

    SciTech Connect

    Daily, W.; Ramirez, A.

    1987-04-01

    Experiments were performed to determine the extent of penetration of drill water into Grouse Canyon densely welded tuff during use of normal drilling practices. Core samples were examined from a borehole cored in a rib of the Rock Mechanics drift in G-tunnel at the Nevada Test Site, Nye County, Nevada. Methylene blue dye was added to the drill water to act as a tracer which stained the rock blue on contact. We found the rock stained blue only in a thin layer about 0.5 mm thick at the surface of the core. However we were concerned about the uniformity of penetration depth observed in the core and this prompted a simple experiment to test the ability of methylene blue to penetrate the matrix of densely welded tuff. We found that in the imbibition process, the dye and water separated such that the water penetrated the matrix to a much greater depth. This result meant that any interpretation of drill water imbibition in borehole core based on this dye as a tracer is unreliable. More important, however, is the conclusion that the presence of methylene blue dye on the rock indicates the presence of tracer water flow, but the absence of the dye does not rule out the presence of water flow. 6 refs.

  5. Investigating the northern Adriatic Sea ecosystem state with a very high resolution model.

    NASA Astrophysics Data System (ADS)

    Zavatarelli, M.; Mattia, G.; Lovato, T.; Colella, S.

    2015-12-01

    The Northern Adriatic sea interannually varyng biogeochemical dynamics has been simulated with the coupled BFM (Biogeochemical flux model) and NEMO (Nucleus for European Modelling of the Ocean) system at very high resolution and under high frequency forcing. Simulations allowed to estimate the role of mesoscale dynamics in modulating the structure of the lower trophic level ecosystem. Particular emphasis is also put on the analysis of the role of the shelf dense water formation on the temporal and spatial dynamics of the biogeochemical processes. Results are synthesized in term of relevant ecosystem proprieties underlying the ecosystem state, and are validated against corresponding remote observations. This is a contribution of the EU-FP7 Project "PERSEUS" (Policy oriented environmental research in the Southern European Seas).

  6. Freshwater mass balance and exchange of water masses with the open sea: the Mljet Lakes (Croatia, Adriatic Sea)

    NASA Astrophysics Data System (ADS)

    Martincic, Urska; Bezak, Nejc; Zagar, Dusan; Makovec, Tihomir; Lucic, Davor; Onofri, Vladimir; Malacic, Vlado

    2016-04-01

    Two karstic seawater lakes (Veliko - Big and Malo - Small Lake) located in the National Park Mljet on the Mljet Island in Croatia were investigated in this study. The Small and the Big Lake cover 0.25 and 1.45 km2, respectively. The two lakes are connected to each other and to the sea by narrow channels. The connecting channel between the Big Lake and the sea is 12 m wide and 3 m deep. The connection to the Small Lake leads through another artificial channel (2.7 m wide and 0.8 m deep). The average salinity of the Big and the Small lake is 37.75 and 36.9, respectively, and the average salinity of the open sea is 38.5. While previous studies have been conducted due to the lakes' unique ecosystem and the karstic characteristics of the area, the main aim of this study was to determine the freshwater mass balance and exchange of water masses with the nearby sea. Several measurement campaigns were performed between 2008 and 2015 when meteorological parameters as well as salinity, water temperature and water velocities in both lakes and the channels were observed. A perpetual year was determined using available meteorological data. The contribution of the surface runoff to both lakes was modelled using the hydrological rainfall-runoff HEC-HMS model. Curve number parameter was estimated using the CLC Corine Land cover and geomorphological maps. Evaporation from the lake was calculated using the Verburg, Kondo and Coare equations. We found that the annual evaporation approximately equals the annual rainfall to the lake surface (cca. 550-600 mm). From the hydrological model and the difference between precipitation and evaporation from the lake surface we calculated the annual net excess of freshwater between 0.5 106 and 0.7 106 m3. The average salinity in both lakes is lower than the salinity in the sea; therefore, we hypothesize that the excess water should be discharged either through the channel between the Big Lake and the open sea or through underwater karstic sink

  7. The Effect of High Wind Bora Events on Water pCO2 and CO2 Exchange in the Coastal Northern Adriatic

    DTIC Science & Technology

    2011-08-05

    coastal Northern Adriatic, such as its circulation , stratification, and heat and momentum fluxes. However, only limited observations on the...such as its circulation , stratification, and heat and momentum fluxes. It generates a wind-induced "double gyre" circulation with a cyclonic gyre...studies have also addressed the circulation and its response to bora in the Gulf of Trieste (GOT), the most northern semi-enclosed basin in Northern

  8. Plasma levels of pollutants are much higher in loggerhead turtle populations from the Adriatic Sea than in those from open waters (Eastern Atlantic Ocean).

    PubMed

    Bucchia, Matteo; Camacho, María; Santos, Marcelo R D; Boada, Luis D; Roncada, Paola; Mateo, Rafael; Ortiz-Santaliestra, Manuel E; Rodríguez-Estival, Jaime; Zumbado, Manuel; Orós, Jorge; Henríquez-Hernández, Luis A; García-Álvarez, Natalia; Luzardo, Octavio P

    2015-08-01

    In this paper we determined the levels of 63 environmental contaminants, including organic (PCBs, organochlorine pesticides, and PAHs) and inorganic (As, Cd, Cu, Pb, Hg and Zn) compounds in the blood of loggerhead turtles (Caretta caretta) from two comparable populations that inhabit distinct geographic areas: the Adriatic Sea (Mediterranean basin) and the Canary Islands (Eastern Atlantic Ocean). All animals were sampled at the end of a period of rehabilitation in centers of wildlife recovery, before being released back into the wild, so they can be considered to be in good health condition. The dual purpose of this paper is to provide reliable data on the current levels of contamination of this species in these geographic areas, and secondly to compare the results of both populations, as it has been reported that marine biota inhabiting the Mediterranean basin is exposed to much higher pollution levels than that which inhabit in other areas of the planet. According to our results it is found that current levels of contamination by organic compounds are considerably higher in Adriatic turtles than in the Atlantic ones (∑PCBs, 28.45 vs. 1.12ng/ml; ∑OCPs, 1.63 vs. 0.19ng/ml; ∑PAHs, 13.39 vs. 4.91ng/ml; p<0.001 in all cases). This is the first time that levels of PAHs are reported in the Adriatic loggerheads. With respect to inorganic contaminants, although the differences were not as great, the Adriatic turtles appear to have higher levels of some of the most toxic elements such as mercury (5.74 vs. 7.59μg/ml, p<0.01). The results of this study confirm that the concentrations are larger in turtles from the Mediterranean, probably related to the high degree of anthropogenic pressure in this basin, and thus they are more likely to suffer adverse effects related to contaminants.

  9. Pervaporation properties of dense polyamide-6 membranes in separation of water-ethanol mixtures

    SciTech Connect

    Kujawski, W.; Waczynski, M.; Lasota, M.

    1996-04-01

    Several dense polyamide-6 membranes were prepared by casting 7 wt% and/or 10 wt% solutions of polymer in trifluoroethanol. The cast membranes were dried at different temperatures from 25 to 80{degrees}C. Sorption and pervaporation properties of PA-6 membranes in water-ethanol mixtures were obtained. The data obtained showed that water was preferentially sorbed into the membrane and transported through the membrane; however, the pervaporation selectivity factor {alpha}{sup PV} was close to unity at higher concentrations. The selectivity parameters in pervaporation were improved for membranes obtained from 10 wt% polymer and dried at higher temperatures.

  10. Long-term trends of DDTs and PCBs in sediment samples collected from the eastern Adriatic coastal waters

    SciTech Connect

    Picer, M.; Picer, N. )

    1991-12-01

    It has been well documented that synthetic chlorinated hydrocarbon residues are widespread throughout the oceanic ecosystem. The Mediterranean Sea, as a semienclosed body of water, is of special interest and there have been many baseline studies to measure the existing levels of these contaminants in various components of the ecosystem. Although declining DDT residues in estuarine mollusks were noted in 1973, there are only a few data describing the long-term monitoring over an fourteen-year period. It is very important to stress that all these samples were analyzed from a single analytical group (mostly by the same analyst), using a uniform methodology which was very successfully intercalibrated during seven international intercalibration exercises.

  11. Tools to Perform Local Dense 3D Reconstruction of Shallow Water Seabed ‡

    PubMed Central

    Avanthey, Loïca; Beaudoin, Laurent; Gademer, Antoine; Roux, Michel

    2016-01-01

    Tasks such as distinguishing or identifying individual objects of interest require the production of dense local clouds at the scale of these individual objects of interest. Due to the physical and dynamic properties of an underwater environment, the usual dense matching algorithms must be rethought in order to be adaptive. These properties also imply that the scene must be observed at close range. Classic robotized acquisition systems are oversized for local studies in shallow water while the systematic acquisition of data is not guaranteed with divers. We address these two major issues through a multidisciplinary approach. To efficiently acquire on-demand stereoscopic pairs using simple logistics in small areas of shallow water, we devised an agile light-weight dedicated system which is easy to reproduce. To densely match two views in a reliable way, we devised a reconstruction algorithm that automatically accounts for the dynamics, variability and light absorption of the underwater environment. Field experiments in the Mediterranean Sea were used to assess the results. PMID:27196913

  12. Tools to Perform Local Dense 3D Reconstruction of Shallow Water Seabed.

    PubMed

    Avanthey, Loïca; Beaudoin, Laurent; Gademer, Antoine; Roux, Michel

    2016-05-17

    Tasks such as distinguishing or identifying individual objects of interest require the production of dense local clouds at the scale of these individual objects of interest. Due to the physical and dynamic properties of an underwater environment, the usual dense matching algorithms must be rethought in order to be adaptive. These properties also imply that the scene must be observed at close range. Classic robotized acquisition systems are oversized for local studies in shallow water while the systematic acquisition of data is not guaranteed with divers. We address these two major issues through a multidisciplinary approach. To efficiently acquire on-demand stereoscopic pairs using simple logistics in small areas of shallow water, we devised an agile light-weight dedicated system which is easy to reproduce. To densely match two views in a reliable way, we devised a reconstruction algorithm that automatically accounts for the dynamics, variability and light absorption of the underwater environment. Field experiments in the Mediterranean Sea were used to assess the results.

  13. Toxicity evaluation of diethylene glycol and its combined effects with produced waters of off-shore gas platforms in the Adriatic Sea (Italy): bioassays with marine/estuarine species.

    PubMed

    Tornambè, Andrea; Manfra, Loredana; Mariani, Livia; Faraponova, Olga; Onorati, Fulvio; Savorelli, Federica; Cicero, Anna Maria; Virno Lamberti, Claudia; Magaletti, Erika

    2012-06-01

    Diethylene glycol (DEG) is commonly used to dehydrate natural gas in off-shore extraction plants and to prevent formation of gas hydrates. It may be released into the sea accidentally or in discharged produced waters (PWs). PWs samples from off-shore gas platforms in the Adriatic Sea (Italy) have been used in this study. The objectives of the study were: a) to evaluate the toxicity of DEG for marine organisms; b) to evaluate if a high DEG content in PWs may alter their toxicity; c) to verify whether the DEG threshold concentration established by the Italian legislation (3.5 g/l) for PWs discharged at sea is safe for marine environment. Ten different species (Vibrio fischeri, Phaeodactylum tricornutum, Dunaliella tertiolecta, Brachionus plicatilis, Artemia franciscana, Tigropus fulvus, Mytilus galloprovincialis, Crassostrea gigas, Tapes philippinarum and Dicentrarchus labrax) have been exposed to DEG; four of these species were also exposed to PWs in combination with DEG. The results showed that: a) DEG is not toxic at levels normally detected in Adriatic PWs; b) DEG in combination with PW showed mainly additive or synergistic effects; c) short-term bioassays showed that the DEG limit of 3.5 g/l could be acceptable.

  14. Trophic transfer and accumulation of mercury in ray species in coastal waters affected by historic mercury mining (Gulf of Trieste, northern Adriatic Sea).

    PubMed

    Horvat, Milena; Degenek, Nina; Lipej, Lovrenc; Snoj Tratnik, Janja; Faganeli, Jadran

    2014-03-01

    Total mercury (Hg) and monomethylmercury (MMHg) were analysed in the gills, liver and muscle of four cartilaginous fish species (top predators), namely, the eagle ray (Myliobatis aquila), the bull ray (Pteromylaeus bovinus), the pelagic stingray (Dasyatis violacea) and the common stingray (Dasyatis pastinaca), collected in the Gulf of Trieste, one of the most Hg-polluted areas in the Mediterranean and worldwide due to past mining activity in Idrija (West Slovenia). The highest Hg and MMHg concentrations expressed on a dry weight (d.w.) basis were found in the muscle of the pelagic stingray (mean, 2.529 mg/kg; range, 1.179-4.398 mg/kg, d.w.), followed by the bull ray (mean, 1.582 mg/kg; range, 0.129-3.050 mg/kg d.w.) and the eagle ray (mean, 0.222 mg/kg; range, 0.070-0.467 mg/kg, d.w.). Only one specimen of the common stingray was analysed, with a mean value in the muscle of 1.596 mg/kg, d.w. Hg and MMHg contents in the bull ray were found to be positively correlated with species length and weight. The highest MMHg accumulation was found in muscle tissue. Hg and MMHg were also found in two embryos of a bull ray, indicating Hg transfer from the mother during pregnancy. The number of specimens and the size coverage of the bull rays allowed an assessment of Hg accumulation with age. It was shown that in bigger bull ray specimens, the high uptake of inorganic Hg in the liver and the slower MMHg increase in the muscle were most probably due to the demethylation of MMHg in the liver. The highest Hg and MMHg contents in all organs were found in the pelagic stingray, which first appeared in the northern Adriatic in 1999. High Hg and MMHg concentrations were also found in prey species such as the banded murex (Hexaplex trunculus), the principal prey of the eagle rays and bull rays, the anchovy (Engraulis encrasicholus) and the red bandfish (Cepola rubescens), which are preyed upon by the pelagic stingray, as well as in zooplankton and seawater. Based on previously published

  15. Simulation of dense water overflows with an isopycnal model and comparisons with laboratory experiments

    NASA Astrophysics Data System (ADS)

    Decamp, S.; Sommeria, J.

    2003-04-01

    We test the ability of an isopycnal model to simulate dense water overflows on a slope, with appropriate diapycnal entrainement. We use the Miami Isopycnic Coordinate Ocean Model, as complemented by Papadakis, Chassignet and Hallberg (2003) to include the parametrization of the Richardson number dependent entrainment of Turner (1986). As a test case, we compare the model results with a laboratory experiment in dynamical similitude with oceanic conditions. The experiments are performed on the Coriolis rotating table (Grenoble, France) with a gravity current flowing down a slope in a uniformly stratified environment, the density of the incoming fluid being that of the bottom water (see communication by Pavia et al.). The large dimensions of the turn-table allows good similarity with the oceanic scale, so that the experiments reproduce a dense flow over a 122 km wide by 3000 m deep continental slope. After a downward motion with intense turbulent mixing, the current is stabilized into a geostrophically balanced along slope jet. We compare the jet position and velocity to laboratory measurements, as well as mixing of the incoming water mass with the environment.

  16. Ultrasonic Method for Concentration and Particle Size Analysis in Dense Coal-water Slurry

    NASA Astrophysics Data System (ADS)

    Xue, Minghua; Su, Mingxu; Dong, Lili; Shang, Zhitao; Cai, Xiaoshu

    2007-06-01

    The concentration and particle size distribution in particulate two-phase flow are the important parameters in a wide variety of industrial areas. For the purpose of on-line characterizing dense coal-water slurry, ultrasonic methods have many advantages, such as no-dilution, real-time and no-invasion, while light-based techniques are not capable of providing information because optical methods normally require the sample to be diluted. In this paper, the modified Urick equation including temperature modification, which can be used to determine concentration from the measurement of velocity in the coal-water slurry, is evaluated on the basis of model analysis and experiments. Combined with the optimum regulation technique inverse algorithm, the particle size distribution of the coal-water slurry is obtained according to the attenuation prediction of Coupled-phase model plus Bouguer-Lambert-Beer-Law scattering model and experimental attenuation at frequencies ranges from 3MHz to 12MHz. This technique brings the possibility of using ultrasound for on-line measurement of dense slurry.

  17. Electrical and thermal properties of warm dense water created by isochoric heating of a submicron water sheet at FLASH

    NASA Astrophysics Data System (ADS)

    Kim, Jongjin; Sperling, Philipp; Chen, Zhijiang; Toleikis, Sven; Curry, Chandra; Mo, Mianzhen; Redmer, Ronald; Daniel, Deponte; Glenzer, Siegfried

    2016-10-01

    The advent of XUV and x-ray free electron lasers has allowed for the development of crystallographic scattering experiments of aqueous species with high brilliance. The hydrodynamic expansion of water heated by an FEL was only recently demonstrated, but processes at shorter time scales have not been studied experimentally. Our research group uses time-resolved optical transmission and reflection measurements to determine fundamental electron transport properties of warm dense matter. This technique has been combined with a recently developed water sheet target. Isochoric heating by FLASH and optical probing requires a flat and windowless water target, with a thickness below a few microns. We describe the development and characterization of a water sheet jet target with thickness down to 200 nm, along with preliminary results with isochoric heating with FLASH operating near the water window. DOE FES under FWP #100182.

  18. A theoretical, two-layer, reduced-gravity model for descending dense water flow on continental shelves/slopes

    NASA Astrophysics Data System (ADS)

    Wang, Jia; Ikeda, Moto; Saucier, Francois J.

    2003-05-01

    A theoretical, two-layer, reduced-gravity model for descending dense water flow on continental shelves/slopes has been developed to investigate the dynamics of bottom dense water plumes. The model is nonsteady state and includes vertical viscosity, the Coriolis force, and bottom friction. An integral solution rather than a perfect analytical expression is derived and, thus, the Simpson's 1/3 rule to approximate the integral is applied. At the very bottom, the dense water plume moves about 45° to the right (left) in the Northern (Southern) Hemisphere, looking downslope. From the bottom, the velocity vector rotates anticyclonically upward, indicating a bottom Ekman spiral that mimics the atmospheric Ekman boundary layer. The dense water within the bottom Ekman layer obeys a three-force balance, while the dense water above the bottom Ekman layer is governed by a two-force balance, which is a geostrophic flow with superimposed cycloidal inertial oscillations oriented from about 25° to 140° to the right (left) of the downslope direction in the Northern (Southern) Hemisphere. The transport within the bottom Ekman layer is directed about 60-70° to the right (left) of the downslope direction in the Northern (Southern) Hemisphere, forming an offshore (cross-isobath) transport in the absence of eddy flux and wind-forcing. The ratio of offshore transport to alongshore transport within the bottom Ekman layer is about 0.19 (19%), while the ratio above the bottom Ekman layer (i.e., geostrophic layer of the dense water) is only 3% (negligible compared to its alongshore transport), which, however, is equivalent in magnitude to its counterpart in the bottom Ekman layer if O(DE/h) ˜ 0.1 (where DE is the bottom Ekman layer thickness and h is the dense water layer thickness). In other words, the bottom Ekman layer and the geostrophic (dense) layer contribute equivalent dense water offshore (each contributes 50%). The magnitude of the descending dense water velocity depends

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

    PubMed

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

    2013-01-01

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

  20. Deep-Sea Bioluminescence Blooms after Dense Water Formation at the Ocean Surface

    PubMed Central

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

    2013-01-01

    The deep ocean is the largest and least known ecosystem on Earth. It hosts numerous pelagic organisms, most of which are able to emit light. Here we present a unique data set consisting of a 2.5-year long record of light emission by deep-sea pelagic organisms, measured from December 2007 to June 2010 at the ANTARES underwater neutrino telescope in the deep NW Mediterranean Sea, jointly with synchronous hydrological records. This is the longest continuous time-series of deep-sea bioluminescence ever recorded. Our record reveals several weeks long, seasonal bioluminescence blooms with light intensity up to two orders of magnitude higher than background values, which correlate to changes in the properties of deep waters. Such changes are triggered by the winter cooling and evaporation experienced by the upper ocean layer in the Gulf of Lion that leads to the formation and subsequent sinking of dense water through a process known as “open-sea convection”. It episodically renews the deep water of the study area and conveys fresh organic matter that fuels the deep ecosystems. Luminous bacteria most likely are the main contributors to the observed deep-sea bioluminescence blooms. Our observations demonstrate a consistent and rapid connection between deep open-sea convection and bathypelagic biological activity, as expressed by bioluminescence. In a setting where dense water formation events are likely to decline under global warming scenarios enhancing ocean stratification, in situ observatories become essential as environmental sentinels for the monitoring and understanding of deep-sea ecosystem shifts. PMID:23874425

  1. Analysis of a dense water pulse following mid-winter opening of polynyas in western Foxe Basin, Canada

    NASA Astrophysics Data System (ADS)

    Defossez, M.; Saucier, F. J.; Myers, P. G.; Caya, D.; Dumais, J.-F.

    2010-01-01

    A recent study has shown that Foxe Basin's dense waters originate from coastal latent heat polynyas and each year replace 2/3rd of the basin's deep waters by propagating southeastwards in Foxe Channel as a gravity current. The formation mechanisms in 2004 of these dense waters are examined here. Strong meteorological events occurring in mid-winter over the domain are responsible for the simultaneous opening of two large polynyas at Lyon Inlet and along Melville Peninsula's eastern coast while a third important and recurrent polynya opens earlier at Hall Beach (northwestern Foxe Basin). Large sea-atmosphere heat exchanges take place in these polynyas, leading to the production of 21.2 × 10 12 kg of sea-ice and 1.53 × 10 12 m 3 of dense water. The ice production rate is on average five to six times higher in the polynyas than in the rest of the basin. Following the topography, the dense waters formed at Hall Beach and along Melville Peninsula cascade into Foxe Channel, while those produced at Lyon Inlet sink directly in the channel through deep convection. The two mechanisms synchronize and combine together when Lyon Inlet and Melville Peninsula polynyas open up. The heat exchanges, sea-ice and brine production rates estimated with a 21-year near-climatology are similar to those found in 2004. The results also show that the produced dense waters can overflow into Hudson Bay.

  2. 3D numerical simulations of dense water cascading in an idealised laboratory setting

    NASA Astrophysics Data System (ADS)

    Wobus, F.; Shapiro, G. I.; Maqueda, M. A. M.; Huthnance, J. M.

    2012-04-01

    The sinking of dense waters flowing from shelf seas down the continental slope "cascading" contributes to ocean ventilation and water mass formation (notably in the Antarctic) and hence ocean circulation. It is also deemed to affect carbon cycling by providing an efficient mechanism of export of carbon-rich surface waters to a greater depth thus contributing to the "carbon pump". Cascading occurs where dense water - formed by cooling, evaporation or ice-formation with brine rejection over the shallow continental shelf - spills over the shelf edge and descends the continental slope as a near-bottom gravity current. During its descent, the plume is modified by mixing and entrainment, and detaches off the slope when reaching its neutral buoyancy level. Cascading over steep bottom topography is studied here in numerical experiments using POLCOMS, a 3D ocean circulation model which utilizes a terrain-following s-coordinate system (Wobus et al, 2011). The model setup is based on a previously conducted (Shapiro and Zatsepin, 1997) laboratory experiment of a continuous dense water flow from a central source on a conical slope in a rotating tank. The governing parameters of the experiments are the density difference between plume and ambient water, the flow rate, the speed of rotation and (in the model) diffusivity and viscosity. The descent of the dense flow as characterised by the length of the plume as a function of time is studied for a range of physical and model parameters. Very good agreement between the model and the laboratory results is shown in dimensional and non-dimensional variables. It is confirmed that a hydrostatic model is capable of reproducing the essential physics of cascading on a very steep slope if the model correctly resolves velocity veering in the bottom boundary layer. Experiments changing the height of the bottom Ekman layer (by changing viscosity) and modifying the plume from a 2-layer system to a stratified regime (by enhancing diapycnal

  3. An uncertainty framework to estimate dense water formation rates : case study in the Northwestern Mediterranean.

    NASA Astrophysics Data System (ADS)

    Waldman, Robin; Somot, Samuel; Herrmann, Marine; Sevault, Florence; Estournel, Claude; Testor, Pierre

    2015-04-01

    The Northwestern Mediterranean (NWMed) sea is a key region for the Mediterranean thermohaline circulation as it includes the main deep water formation sites of the Western Mediterranean. The Mediterranean Ocean Observing System for the Environment (MOOSE) has been implemented since 2007 over that region to characterize the space and time variability of the main water masses up to interannual (yearly summer cruises) scale. However, despite a large covering of the NWMed region, the limited number of conductivity, temperature and depth (CTD) casts leads to subsampling errors and advocates for an uncertainty assessment of large-scale hydrology estimates. This study aims at estimating the error related to subsampling in time and space. For that purpose, an Observing System Simulation Experiment (OSSE) is performed with an eddy-permitting Mediterranean sea model (NEMOMED12) and an eddy-resolving NWMed sea model (SYMPHONIE). A subsampling of the full model fields in time and space allows for an error estimate in terms of large-scale hydrology. The methodology is applied to dense water volume estimates for the period july 2012 - july 2013. Secondly, an optimization framework is proposed to evaluate and improve MOOSE network's performances under a series of scientific constraints. The results will be discussed for an application in MOOSE observing network, as well as the main assumptions, the stakes and limitations of this framework.

  4. Wind and tidal mixing controls on stratification and dense water outflows in a large hypersaline bay

    NASA Astrophysics Data System (ADS)

    Hetzel, Yasha; Pattiaratchi, Charitha; Lowe, Ryan; Hofmeister, Richard

    2015-09-01

    In Shark Bay, a large inverse estuary in Western Australia, longitudinal density gradients establish a gravitational circulation that is important for Bay-ocean exchange and transport of biological material such as larvae. The relative contributions of energy from wind and tidal mixing on the control of vertical stratification and gravitational circulation were investigated using the three-dimensional baroclinic ocean circulation model (General Estuarine Transport Model, GETM). In this large inverse estuary, the effects of the winds and tides on vertical mixing were found to be of similar magnitude. A critical depth of ˜15 m was identified that determined whether winds or tides or a combination of the two was required to create vertically mixed conditions. Where it was shallower than the critical depth, either the wind or tide could fully mix the water column. In contrast, a combination of both winds and tides was required to mix the deeper channels. Density-driven circulation peaked 0-3 days after periods of maximum stratification, resulting in a fortnightly modulation of dense water outflows along the seabed following the tidal stage. Salt flux calculations provided new evidence for the predominance of outflow through the deeper northern entrance channel where outflows persisted through all stages of the tide. In contrast, outflows through the western channel were more intermittent with a stronger tidal component. Wind driven lateral circulation between the entrances was also important and could temporarily reverse the circulation during northerly wind events.

  5. 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.

  6. A sensitivity study of the dense shelf water formation in the Okhotsk Sea

    NASA Astrophysics Data System (ADS)

    Sasajima, Y.; Hasumi, H.; Nakamura, T.

    2010-11-01

    Sensitivity of Dense Shelf Water (DSW) formation to tidal mixing around the Kuril Straits, wind stress, and river runoff in the Okhotsk Sea is examined by an ice-ocean coupled model. Horizontal resolution of the model is set to 3-8 km in the northern Okhotsk Sea for well resolving the coastal polynyas which is believed to be the principal region of DSW formation. The model shows a good performance in terms of sea ice production and the consequent DSW formation. DSW is also found to be formed in the offshore region apart from the coastal polynya. DSW is defined independently for each experiment such that it identifies the water influenced by brine. By introducing such definition the sensitivity of the DSW formation is assessed separately for change of density and that of formation rate. The density of DSW exhibits high sensitivity to all the elements considered herein, while its formation rate is sensitive only to winds. Winds affect the DSW formation rate mainly by influencing that occurs in the offshore region.

  7. Hot and dense water in the inner 25 au of SVS13-A

    NASA Astrophysics Data System (ADS)

    Codella, C.; Ceccarelli, C.; Bianchi, E.; Podio, L.; Bachiller, R.; Lefloch, B.; Fontani, F.; Taquet, V.; Testi, L.

    2016-10-01

    In the context of the ASAI (Astrochemical Surveys At IRAM) project, we carried out an unbiased spectral survey in the millimetre window towards the well known low-mass Class I source SVS13-A. The high sensitivity reached (3-12 mK) allowed us to detect at least six HDO broad (full width at half-maximum ˜4-5 km s-1) emission lines with upper level energies up to Eu = 837 K. A non-local thermodynamic equilibrium Large Velocity Gradient (LVG) analysis implies the presence of very hot (150-260 K) and dense (≥3 × 107 cm-3) gas inside a small radius (˜25 au) around the star, supporting, for the first time, the occurrence of a hot corino around a Class I protostar. The temperature is higher than expected for water molecules are sublimated from the icy dust mantles (˜100 K). Although we cannot exclude we are observing the effects of shocks and/or winds at such small scales, this could imply that the observed HDO emission is tracing the water abundance jump expected at temperatures ˜220-250 K, when the activation barrier of the gas phase reactions leading to the formation of water can be overcome. We derive X(HDO) ˜ 3 × 10-6, and a H2O deuteration ≥1.5 × 10-2, suggesting that water deuteration does not decrease as the protostar evolves from the Class 0 to the Class I stage.

  8. Atmospheric and oceanologic conditions favouring large bioproduction of northern Adriatic

    NASA Astrophysics Data System (ADS)

    Kraus, Romina; Lučić, Davor; Njire, Jakica; Djakovac, Tamara; Precali, Robert; Supić, Nastjenjka

    2016-04-01

    An interdisciplinary study based on long term data collected in the northern Adriatic relieved winter period to be crucial for the total annual zooplankton production in the region. Namely, yearly averages of some investigated zooplankton species in the 2000-2007 interval were highly related to their February and/or March abundances. The large winter zooplankton abundances appeared in winters of the "A type", in which freshened waters from the Po River spread over the region. Also, the production of phytoplankton was in winters of the "A type" higher than in winters of the "B type", in which these waters are restricted to the coastal areas and do not impact the open sea. That was presumably due to increase in nutrients. In fact, the total inorganic nitrogen and ortophosphate concentration in eastern part reached maximal February values in the 1990-2007 interval in winters of the "A type". Spreading of the Po River water across the northern Adriatic and appearance of the two winter types depends on the existing geostrophic circulation patterns and atmospheric and hydrologic conditions in the preceding months, thus enabling forecast. Obtained results are basis for the future theoretical ecological model which can explain long term changes in bioproduction in the region and be used in planning future environment actions aimed to sustained development, especially as winter phytoplankton and zooplankton production seems to reflect on annual catch of small pelagic fish important for Adriatic fishery, anchovy (Engraulis encrasicolus).

  9. Impact of winter oceanographic conditions on zooplankton abundance in northern Adriatic with implications on Adriatic anchovy stock prognosis

    NASA Astrophysics Data System (ADS)

    Kraus, Romina; Supić, Nastjenjka; Lučić, Davor; Njire, Jakica

    2015-12-01

    Anchovy, Engraulis encrasicolus (L.), is commercially one of the most important Adriatic small pelagic fish. Despite the prevailing oligotrophication trend in the northern Adriatic (NA), the anchovy catch increased after 2000, coinciding with an increased number of the winter type A occurrences, when Po River waters are favoured to spread across the NA. Namely, winter type A is characterised by conditions resulting with Po River waters spreading across the NA along with salinity decrease. On the contrary, in winters of type B, salinity is high. We hypothesized in previous paper, based on correlation between circulation patterns and phytoplankton with anchovy catch, that excess feeding of anchovy in this winter pre-spawning period (February) can lead to increased amounts of the anchovy eggs two months later and subsequently to the total fish catch of the same year. In this paper, we investigate in more details and based on longer time series the relation between anchovy catch and winter circulation patterns of the NA. Additionally, we studied the association between anchovy catch and zooplankton, as anchovy is predominantly zooplanktivorous. We found that zooplankton abundances in winters of A type enhance and that ciliates play an important role in the NA anchovy food web and enrichment of the region with anchovy. Finally, the results of our investigation might in time represent the basics for a sustainable anchovy management in the Adriatic Sea as they enable the development of prediction models of the anchovy stock.

  10. Matching oceanography and genetics at the basin scale. Seascape connectivity of the Mediterranean shore crab in the Adriatic Sea.

    PubMed

    Schiavina, M; Marino, I A M; Zane, L; Melià, P

    2014-11-01

    Investigating the interactions between the physical environment and early life history is crucial to understand the mechanisms that shape the genetic structure of marine populations. Here, we assessed the genetic differentiation in a species with larval dispersal, the Mediterranean shore crab (Carcinus aestuarii) in the Adriatic Sea (central Mediterranean), and we investigated the role of oceanic circulation in shaping population structure. To this end, we screened 11 polymorphic microsatellite loci from 431 individuals collected at eight different sites. We found a weak, yet significant, genetic structure into three major clusters: a northern Adriatic group, a central Adriatic group and one group including samples from southern Adriatic and Ionian seas. Genetic analyses were compared, under a seascape genetics approach, with estimates of potential larval connectivity obtained with a coupled physical-biological model that integrates a water circulation model and a description of biological traits affecting dispersal. The cross-validation of the results of the two approaches supported the view that genetic differentiation reflects an oceanographic subdivision of the Adriatic Sea into three subbasins, with circulation patterns allowing the exchange of larvae through permanent connections linking north Adriatic sites and ephemeral connections like those linking the central Adriatic with northern and southern locations.

  11. On the impact of the Bimodal Oscillating System (BiOS) on the biogeochemistry and biology of the Adriatic and Ionian Seas (Eastern Mediterranean)

    NASA Astrophysics Data System (ADS)

    Civitarese, G.; Gačić, M.; Lipizer, M.; Eusebi Borzelli, G. L.

    2010-12-01

    Analysis of 20-year time-series of the vertically averaged salinity and nutrient data in the Southern Adriatic shows that the two parameters are subject to strong decadal variability. In addition, it is documented that nutrient and salinity variations are out of phase. Nutrients in the Ionian and in the Adriatic vary in parallel except that generally the nutrient content in the Adriatic is lower than in the Ionian, a fact that has been attributed to primary producer consumption following the winter convective mixing. As shown earlier, North Ionian Gyre (NIG) changes its circulation sense on a decadal scale due to the Bimodal Oscillating System, i.e. the feedback mechanism between the Adriatic and Ionian. Cyclonic circulation causes a downwelling of the nitracline along the borders of the NIG and a decrease in the nutrient content of the water flowing into the Adriatic across the Otranto Strait, and vice versa. In addition, the highly oligotrophic central area of the Ionian shows annual blooms only during cyclonic NIG circulation. Inversion of the sense of the NIG results in the advection of Modified Atlantic Water or of the Levantine/Eastern Mediterranean waters in the Adriatic. Here, we show that the presence of allochtonous organisms from Atlantic/Western Mediterranean and Eastern Mediterranean/temperate zone in the Adriatic are concurrent with the anticyclonic and cyclonic circulations of the NIG, respectively. On the basis of the results presented, a revision of the theory of Adriatic ingressions formulated in the early 1950s is proposed.

  12. Adriatic seiche decay and energy loss to the Mediterranean

    NASA Astrophysics Data System (ADS)

    Cerovečki, Ivana; Orlić, Mirko; Hendershott, Myrl C.

    1997-12-01

    A salient feature of sea level records from the Adriatic Sea is the frequent occurrence of energetic seiches of period about 21 h. Once excited by a sudden wind event, such seiches often persist for days. They lose energy either to friction within the Adriatic, or by radiation through Otranto Strait into the Mediterranean. The free decay time of the dominant (lowest mode) seiche was determined from envelopes of handpassed sea level residuals from three locations (Bakar, Split and Dubrovnik) along the Croatian coast during twelve seiche episodes between 1963 and 1986 by taking into consideration only time intervals when the envelopes decreased exponentially in time, when the modelled effects of along-basin winds were smaller than the error of estimation of decay time from the envelopes and when across-basin winds were small. The free decay time thus obtained was 3.2±0.5 d. This value is consonant with the observed width of the spectral peak. The decay caused by both bottom friction and radiation was included in a one dimensional variable cross section shallow water model of the Adriatic. Bottom friction is parameterized by the coefficient k appearing in the linearized bottom stress term ρ0u (where u is the along-basin velocity and ρ0 the fluid density). The coefficient k is constrained by values obtained from linearization of the quadratic bottom stress law using estimates of near bottom currents associated with the seiche, with wind driven currents, with tides and with wind waves. Radiation is parameterized by the coefficient f appearing in the open strait boundary condition ζ = auh/ c (where ζ is sea level, h is depth and c is phase speed). This parameterization of radiation provides results comparable to allowing the Adriatic to radiate into an unbounded half plane ocean. Repeated runs of the model delineate the dependence of model free seiche decay time on k and a, and these plus the estimates of k allow estimation of a. The principle conclusions of this

  13. Changes in the Adriatic oceanographic properties induced by the Eastern Mediterranean Transient

    NASA Astrophysics Data System (ADS)

    Vilibić, I.; Matijević, S.; Šepić, J.

    2012-01-01

    Long-term time series of physical and chemical parameters collected between 1960 and 2010 along the Palagruža Sill transect, middle Adriatic Sea, have been investigated in terms of average water properties and their variability. Nutrients, especially orthophosphates, reached rather higher levels of concentration below the euphotic zone between 1991 and 1998, the highest in the investigated period. Simultaneously, the N:P ratio, which is normally larger than 25:1, decreased to values less than 16:1 in the euphotic zone, indicating a switch from typical phosphorus-limited to nitrogen-limited preconditioning of the primary production. Higher-than-usual nutrient levels, coupled with lower-than-usual temperature, salinity and dissolved oxygen, have been attributed to the intermediate inflow of the nutrient richer Western Mediterranean waters to the Adriatic, entering the Adriatic during the anticyclonic phase of the Bimodal Adriatic-Ionian Oscillation (BiOS). The BiOS and the Northern Ionian anticyclone have been uniquely strengthened by the Eastern Mediterranean Transient occurring in the early 1990s. The observed changes have a potential to impact the primary production and presumably the whole trophic chain in the Adriatic and were likely responsible for the observed fluctuation in abundances of various species and fish stock, indicating a high relevance of the observed physical processes.

  14. Variability of PAHs and trace metals in the sediments in relation to environmental characteristics of the bottom layer in the middle Adriatic Sea

    NASA Astrophysics Data System (ADS)

    Grilli, Federica; Frapiccini, Emanuela; Campanelli, Alessandra; Guicciardi, Stefano; Marini, Mauro; Marasovic, Ivona; Grbec, Branka; Skejić, Sanda; Ujević, Ivana; Lušić, Jelena

    2015-04-01

    In the framework of the project PERSEUS (Policy-oriented marine Environmental Research in the Southern EUropean Seas), two interdisciplinary surveys were carried out in April 2013 and April 2014 in the middle Adriatic Sea along the Pescara-Sibenik transect (Jabuka Pits area) and Vieste-Split transect (Palagruza Sill area) with Croatian research vessel "Bios II" and the Italian research vessel "G. Dallaporta", respectively. The main objective of these research cruises was the implementation of the Marine Strategy Framework Directive (MSFD) in the Adriatic region for collecting physical, chemical and biological data in order to get a better understanding of whole Adriatic ecosystem. The two transects are already recognised as a key areas for the interception and the study of dense water modification (Zore-Armanda, 1963; Marini et al., 2006; Grilli et al., 2013). Due to seasonal circulation patterns, they are characterized by high temporal variability of the thermohaline structure (Grbec and Morović, 1997; Vilibić, et al., 2004) and other oceanographic parameters. Long term oceanographic records from the Middle Adriatic enable better understanding of the ecosystem response to changes of atmospheric and sea conditions through physical, chemical and biological processes (Marasović et al., 1995). Several oceanographic parameters relevant and useful for the ecosystem assessment of the two areas (temperature, salinity, density, fluorescence, oxygen, nutrients, chlorophyll, phyto- and zoo-plankton as well as selected pollutants , trace metals and Polycyclic Aromatic Hydrocarbons-PAHs in sediments) were collected. In the present work, the variations of PAHs and trace metals concentration in the marine sediments are presented in relation to the physical and chemical characteristics of the bottom layer. A constant influx of metal induces more intense accumulation of anthropogenic metals, especially Cd, in sediment from Jabuka Pit, and the metal content slightly increases

  15. Estrogen and androgen receptor activities of hydraulic fracturing chemicals and surface and ground water in a drilling-dense region

    USGS Publications Warehouse

    Kassotis, Christopher D.; Tillitt, Donald E.; Davis, J. Wade; Hormann, Anette M.; Nagel, Susan C.

    2014-01-01

    The rapid rise in natural gas extraction using hydraulic fracturing increases the potential for contamination of surface and ground water from chemicals used throughout the process. Hundreds of products containing more than 750 chemicals and components are potentially used throughout the extraction process, including more than 100 known or suspected endocrine-disrupting chemicals. We hypothesized thataselected subset of chemicalsusedin natural gas drilling operationsandalso surface and ground water samples collected in a drilling-dense region of Garfield County, Colorado, would exhibit estrogen and androgen receptor activities. Water samples were collected, solid-phase extracted, and measured for estrogen and androgen receptor activities using reporter gene assays in human cell lines. Of the 39 unique water samples, 89%, 41%, 12%, and 46% exhibited estrogenic, antiestrogenic, androgenic, and antiandrogenic activities, respectively. Testing of a subset of natural gas drilling chemicals revealed novel antiestrogenic, novel antiandrogenic, and limited estrogenic activities. The Colorado River, the drainage basin for this region, exhibited moderate levels of estrogenic, antiestrogenic, and antiandrogenic activities, suggesting that higher localized activity at sites with known natural gas–related spills surrounding the river might be contributing to the multiple receptor activities observed in this water source. The majority of water samples collected from sites in a drilling-dense region of Colorado exhibited more estrogenic, antiestrogenic, or antiandrogenic activities than reference sites with limited nearby drilling operations. Our data suggest that natural gas drilling operationsmayresult in elevated endocrine-disrupting chemical activity in surface and ground water.

  16. Estrogen and androgen receptor activities of hydraulic fracturing chemicals and surface and ground water in a drilling-dense region.

    PubMed

    Kassotis, Christopher D; Tillitt, Donald E; Davis, J Wade; Hormann, Annette M; Nagel, Susan C

    2014-03-01

    The rapid rise in natural gas extraction using hydraulic fracturing increases the potential for contamination of surface and ground water from chemicals used throughout the process. Hundreds of products containing more than 750 chemicals and components are potentially used throughout the extraction process, including more than 100 known or suspected endocrine-disrupting chemicals. We hypothesized that a selected subset of chemicals used in natural gas drilling operations and also surface and ground water samples collected in a drilling-dense region of Garfield County, Colorado, would exhibit estrogen and androgen receptor activities. Water samples were collected, solid-phase extracted, and measured for estrogen and androgen receptor activities using reporter gene assays in human cell lines. Of the 39 unique water samples, 89%, 41%, 12%, and 46% exhibited estrogenic, antiestrogenic, androgenic, and antiandrogenic activities, respectively. Testing of a subset of natural gas drilling chemicals revealed novel antiestrogenic, novel antiandrogenic, and limited estrogenic activities. The Colorado River, the drainage basin for this region, exhibited moderate levels of estrogenic, antiestrogenic, and antiandrogenic activities, suggesting that higher localized activity at sites with known natural gas-related spills surrounding the river might be contributing to the multiple receptor activities observed in this water source. The majority of water samples collected from sites in a drilling-dense region of Colorado exhibited more estrogenic, antiestrogenic, or antiandrogenic activities than reference sites with limited nearby drilling operations. Our data suggest that natural gas drilling operations may result in elevated endocrine-disrupting chemical activity in surface and ground water.

  17. Drifter observations of surface circulation in the Adriatic Sea between December 1994 and March 1996

    NASA Astrophysics Data System (ADS)

    Poulain, Pierre-Marie

    1999-04-01

    The trajectories of satellite-tracked drifters are used to describe the characteristics of the subtidal surface circulation in the Adriatic Sea between December 1994 and March 1996. The mean surface circulation inferred from the drifter velocities consists of an elongated basin-wide cyclonic gyre with northward flow on the eastern side and return southward currents near the Italian coast (western side). This global circulation feature is composed of two sub-basin cyclonic, circulatory velocity patterns around the two main deeps of the Adriatic, i.e., the Jabuka and the South Adriatic Pits. The mean currents are maximum (greater than 40 cm s -1) near the outside (coastal) perimeter of these features. Specific zones of horizontal convergence of the mean flow were identified by converging drifters. Other areas in the open sea appeared to be diverging as drifters were reluctant to enter them. The seasonal modulation of the surface circulation was resolved in the lower southern Adriatic Sea and in the Strait of Otranto. An enhanced horizontal shear (northward flow on the eastern flank and southward currents on the western side) in the strait and an increased cyclonic gyre circulation around the South Adriatic Pit were observed in winter. The inflow of Ionian water and the subsequent cyclonic veering around the South Adriatic Pit are minimum in spring. In summer, the southward currents outflowing on the Italian shelf are maximum. Qualitative comparison between the drifter-inferred velocities and contemporaneous moored current observations discloses substantial vertically coherent current variations within the top 50 m of water that give rise to significant transport variability. In addition to the seasonal variations, surface subtidal velocity fluctuations with scales ranging from a few days to a few weeks are ubiquitous in both the drifter and moored observations. They are due to transient wind events, to changes in the buoyancy input (river runoff) and to instability

  18. A shallow water model for dense gas simulation in urban areas

    SciTech Connect

    Brown, Michael; Williams, Mike D; Gowardhan, Akshay; Brambilla, Sara; Manca, Davide

    2009-01-01

    Large quantities of toxic chemicals are stored at industrial facilities and transported around the country via train and truck. In the event of an accidental release, many of these chemicals are released as heavier-than-air gases that stay low to the ground as they are transported by the wind . Breathing height concentrations can remain high due to reduced vertical mixing and hazard zone coverage area can be larger due to near-source gravitational slumping . A number of fast-response dense gas dispersion models have been developed and are routinely used to deal with heavier-than-air releases over unobstructed terrain. If a release were to occur in a built-up environment, however, the effects of buildings and other obstacles will significantly alter the initial spreading, the transport direction, and the amount of mixing of the dense gas cloud . We have developed a new fast-running dense gas dispersion model that is intended for handling releases in cities and at large industrial facilities. In this paper we describe the scheme employed and how the model has been integrated into the Quick Urban & Industrial Complex (QUIC) dispersion modeling system.

  19. Laterally spreading iron, humic-like dissolved organic matter and nutrients in cold, dense subsurface water of the Arctic Ocean

    PubMed Central

    Hioki, Nanako; Kuma, Kenshi; Morita, Yuichirou; Sasayama, Ryouhei; Ooki, Atsushi; Kondo, Yoshiko; Obata, Hajime; Nishioka, Jun; Yamashita, Youhei; Nishino, Shigeto; Kikuchi, Takashi; Aoyama, Michio

    2014-01-01

    The location and magnitude of oceanic iron sources remain uncertain owing to a scarcity of data, particularly in the Arctic Ocean. The formation of cold, dense water in the subsurface layer of the western Arctic Ocean is a key process in the lateral transport of iron, macronutrients, and other chemical constituents. Here, we present iron, humic-like fluorescent dissolved organic matter, and nutrient concentration data in waters above the continental slope and shelf and along two transects across the shelf–basin interface in the western Arctic Ocean. We detected high concentrations in shelf bottom waters and in a plume that extended in the subsurface cold dense water of the halocline layer in slope and basin regions. At σθ = 26.5, dissolved Fe, humic-like fluorescence intensity, and nutrient maxima coincided with N* minima (large negative values of N* indicate significant denitrification within shelf sediments). These results suggest that these constituents are supplied from the shelf sediments and then transported laterally to basin regions. Humic dissolved organic matter probably plays the most important role in the subsurface maxima and lateral transport of dissolved Fe in the halocline layer as natural Fe-binding organic ligand. PMID:25345398

  20. Segregation of acid plume pixels from background water pixels, signatures of background water and dispersed acid plumes, and implications for calculation of iron concentration in dense plumes

    NASA Technical Reports Server (NTRS)

    Bahn, G. S.

    1978-01-01

    Two files of data, obtained with a modular multiband scanner, for an acid waste dump into ocean water, were analyzed intensively. Signatures were derived for background water at different levels of effective sunlight intensity, and for different iron concentrations in the dispersed plume from the dump. The effect of increased sunlight intensity on the calculated iron concentration was found to be relatively important at low iron concentrations and relatively unimportant at high values of iron concentration in dispersed plumes. It was concluded that the basic equation for iron concentration is not applicable to dense plumes, particularly because lower values are indicated at the very core of the plume, than in the surrounding sheath, whereas radiances increase consistently from background water to dispersed plume to inner sheath to innermost core. It was likewise concluded that in the dense plume the iron concentration would probably best be measured by the higher wave length radiances, although the suitable relationship remains unknown.

  1. Analysis of polar organic contaminants in surface water of the northern Adriatic Sea by solid-phase extraction followed by ultrahigh-pressure liquid chromatography-QTRAP® MS using a hybrid triple-quadrupole linear ion trap instrument.

    PubMed

    Loos, Robert; Tavazzi, Simona; Paracchini, Bruno; Canuti, Elisabetta; Weissteiner, Christof

    2013-07-01

    Water-soluble polar organic contaminants are discharged by rivers, cities, and ships into the oceans. Little is known on the fate, pollution effects, and thresholds of toxic chemical mixtures in the marine environment. A new trace analytical method was developed for the multi-compound analysis of polar organic chemical contaminants in marine waters. The method is based on automated solid-phase extraction (SPE) of one-liter water samples followed by ultrahigh-pressure liquid chromatography triple-quadrupole linear ion-trap mass spectrometry (UHPLC-QTRAP(®) MS). Marine water samples from the open Adriatic Sea taken 16 km offshore from Venice (Italy) were analyzed. Method limits of quantification (LOQs) in the low picogram per liter (pg/l) concentration range were achieved. Among the 67 target chemicals analyzed, 45 substances could be detected above the LOQ. The chemicals detected at the highest concentrations were caffeine (up to 367 ng/l), nitrophenol (36 ng/l), 2,4-dinitrophenol (34 ng/l), 5-methyl-1H-benzotriazole (18.5 ng/l), sucralose (11 ng/l), 1H-benzotriazole (9.2 ng/l), terbuthylazine (9 ng/l), alachlor (7.7 ng/l), atrazine-desisopropyl (6.6 ng/l), diethyltoluamide (DEET) (5.0 ng/l), terbuthylazine-desethyl (4.3 ng/l), metolachlor (2.8 ng/l), perfluorooctanoic acid (PFOA) (2.5 ng/l), perfluoropentanoic acid (PFPeA) (2.3 ng/l), linuron (2.3 ng/l), perfluorohexanoic acid (PFHxA) (2.2 ng/l), diuron (2.0 ng/l), perfluorohexane sulfonate (PFHxS) (1.6 ng/l), simazine (1.6 ng/l), atrazine (1.5 ng/l), and perfluorooctane sulfonate (PFOS) (1.3 ng/l). Higher concentrations were detected during summer due to increased levels of tourist activity during this period.

  2. Phytoplankton distribution across the southeast Adriatic continental and shelf slope to the west of Albania (spring aspect).

    PubMed

    Viličić, Damir; Silović, Tina; Kuzmić, Milivoj; Mihanović, Hrvoje; Bosak, Sunčica; Tomažić, Igor; Olujić, Goran

    2011-06-01

    We present the first insight to the oceanography of the southeastern Adriatic Sea, where coastal water influenced by Albanian rivers comes into contact with the inflowing oligotrophic Eastern Adriatic Current (Ionian Surface Water and Levantine Intermediate Water). A distinct plankton distribution was observed on each side of the shelf break hydrographic boundary in May 2009, during gradual warming of the surface waters. The prochlorophytes accumulated along the nutricline above the shelf and continental slope. The phosphorus limited inshore waters were dominated by a small diatom Chaetoceros circinalis, dinoflagellates, cryptophytes, autotrophic picoplankton, and heterotrophic nanoplankton. The offshore surface layer was characterized by bigger nanoplankton (coccolithophorids, green flagellates). Low nutrient concentrations influence relatively low productivity not only above the Albanian shelf but also further to the north along the Montenegrine and Croatian coastal Adriatic Sea.

  3. Global view of sea-ice production in polynyas and its linkage to dense/bottom water formation

    NASA Astrophysics Data System (ADS)

    Ohshima, Kay I.; Nihashi, Sohey; Iwamoto, Katsushi

    2016-12-01

    Global overturning circulation is driven by density differences. Saline water rejected during sea-ice formation in polynyas is the main source of dense water, and thus sea-ice production is a key factor in the overturning circulation. Due to difficulties associated with in situ observation, sea-ice production and its interannual variability have not been well understood until recently. Methods to estimate sea-ice production on large scales have been developed using heat flux calculations based on satellite microwave radiometer data. Using these methods, we present the mapping of sea-ice production with the same definition and scale globally, and review the polynya ice production and its relationship with dense/bottom water. The mapping demonstrates that ice production rate is high in Antarctic coastal polynyas, in contrast to Arctic coastal polynyas. This is consistent with the formation of Antarctic Bottom Water (AABW), the densest water mass which occupies the abyssal layer of the global ocean. The Ross Ice Shelf polynya has by far the highest ice production in the Southern Hemisphere. The Cape Darnley polynya (65°E-69°E) is found to be the second highest production area and recent observations revealed that this is the missing (fourth) source of AABW. In the region off the Mertz Glacier Tongue (MGT), the third source of AABW, sea-ice production decreased by as much as 40 %, due to the MGT calving in early 2010, resulting in a significant decrease in AABW production. The Okhotsk Northwestern polynya exhibits the highest ice production in the Northern Hemisphere, and the resultant dense water formation leads to overturning in the North Pacific, extending to the intermediate layer. Estimates of its ice production show a significant decrease over the past 30-50 years, likely causing the weakening of the North Pacific overturning. These regions demonstrate the strong linkage between variabilities of sea-ice production and bottom/intermediate water formation. The

  4. On the impact of the Bimodal Oscillating System (BiOS) on the biogeochemistry and biology of the Adriatic and Ionian Seas (Eastern Mediterranean)

    NASA Astrophysics Data System (ADS)

    Civitarese, G.; Gačić, M.; Lipizer, M.; Borzelli, G. L. E.

    2010-09-01

    Analysis of 20-year time-series of the vertically averaged salinity and nutrient data in the South Adriatic shows that the two parameters are subject to strong decadal variability. In addition, nutrient and salinity variations are out of phase. Nutrients in the Ionian and in the Adriatic vary in parallel except that often the nutrient content in the Adriatic is lower than in the Ionian, a fact that has been attributed to primary producer consumption following the winter convective mixing. Horizontal distribution of the nitracline depth in the Ionian suggests that nutrient content in the Adriatic is a function of the circulation pattern in the Ionian that wells up or wells down the nitracline: cyclonic circulation causes a downwelling of the nitracline along the borders of the Northern Ionian Gyre (NIG) and a decrease in the nutrient content of the water flowing into the Adriatic across the Otranto Strait, and vice versa. The circulation variations are due to the Bimodal Oscillating System, i.e. the feedback mechanism between the Adriatic and Ionian. Inversion of the sense of the NIG results in the advection of Modified Atlantic Water or of the Levantine/Eastern Mediterranean (EMed) waters in the Adriatic. Here, we show that the presence of allochtonous organisms from Atlantic/Western Mediterranean (WMed) and EMed/temperate zone in the Adriatic are concomitant with the anticyclonic and cyclonic circulations, respectively, of the NIG. As a consequence of the NIG inversions, in the Ionian, this highly oligotrophic zone shows annual blooms in its central area only during cyclonic circulation. On the basis of the results presented, a revision of the theory of Adriatic ingressions formulated in the early 1950s is proposed.

  5. Behavior of fish predators and their prey: habitat choice between open water and dense vegetation

    USGS Publications Warehouse

    Savino, Jacqueline F.; Stein, Roy A.

    1989-01-01

    Behavior of largemouth bass, Micropterus salmoides, and northern pike, Esox lucius, foraging on fathead minnows, Pimephales promelas, or bluegills, Lepomis macrochirus, was quantified in pools with 50% cover (half the pool had artificial stems at a density of 1000 stems m−2). Both predators spent most of their time in the vegetation. Largemouth bass searched for bluegills and ambushed minnows, whereas the relatively immobile northern pike ambushed all prey. Minnows were closer to predators and were captured more frequently than bluegills. Even when minnows dispersed, they moved continually and eventually wandered within striking distance of a predator. Bluegills dispersed in the cover with predators. Bass captured the few bluegills that strayed into the open and pike captured those that approached too closely in the cover. The ability of predators to capture prey while residing in habitats containing patches of dense cover may explain their residence in areas often considered to be poor ones for foraging.

  6. Distribution of phosphorus in the eastern Adriatic Sea sediments (Croatia)

    NASA Astrophysics Data System (ADS)

    Matijević, Slavica; Bogner, Danijela; Kušpilić, Grozdan; Veža, Jere

    2014-05-01

    Phosphorus (P) is very important nutrient for the eastern Adriatic Sea owing to its limiting role in the primary production. Orthophosphate concentrations are low (median HPO42- value: 0.039 µmol dm-3) as a consequence of relatively small number of freshwater inflows and cyclonic circulation of oligotrophic eastern Mediterranean water masses. Due to anthropogenic influence in coastal areas such as bays, estuaries and channel waters, P concentrations increment occurred leading to the formation of trophic gradient from the open sea towards the coast. As marine sediment presents the ultimate sink for particulate organic P from the water column, as well as for inorganic P forms, knowledge about distribution of different sediment P species is of great importance for understanding the burial, diagenesis and environmental geochemical significance of P. This paper presents results of P distribution at the eastern Adriatic sites of different trophic status (open sea, channel, estuary, semi-enclosed bay under the anthropogenic influence and fish farms) during 2002-2012. In the water column dissolved and particulate inorganic and organic P were analyzed. In all sediments total phosphorus (organic and inorganic P) was determined, while at certain sites beside organic P, inorganic P forms were examined using modified SEDEX methods (P in biogenic - P-FD; authigenic - P-AUT and in detrital apatite - P-DET; phosphorus bound to iron oxides and hydroxides - P-Fe). Various geochemical variables in the water column and sediment (HPO42- concentration, sediment redox potential, granulometric composition, carbonate content, iron, organic carbon and total nitrogen content) were also investigated. Results proved total P concentrations range between 3 and 161 µmol g-1, with highest values at sites under the strong anthropogenic impact including fish farms, estuaries and bay areas. Major inorganic P species in the eastern Adriatic was P-Fe form. Fish debris P species P-FD, prevailed in

  7. Observed and simulated trophic index (TRIX) values for the Adriatic Sea basin

    NASA Astrophysics Data System (ADS)

    Fiori, Emanuela; Zavatarelli, Marco; Pinardi, Nadia; Mazziotti, Cristina; Ferrari, Carla Rita

    2016-09-01

    The main scope of the Marine Strategy Framework Directive is to achieve good environmental status (GES) of the EU's marine waters by 2020, in order to protect the marine environment more effectively. The trophic index (TRIX) was developed by Vollenweider in 1998 for the coastal area of Emilia-Romagna (northern Adriatic Sea) and was used by the Italian legislation to characterize the trophic state of coastal waters. We compared the TRIX index calculated from in situ data ("in situ TRIX") with the corresponding index simulated with a coupled physics and biogeochemical numerical model ("model TRIX") implemented in the overall Adriatic Sea. The comparison between in situ and simulated data was carried out for a data time series on the Emilia-Romagna coastal strip. This study shows the compatibility of the model with the in situ TRIX and the importance of the length of the time series in order to get robust index estimates. The model TRIX is finally calculated for the whole Adriatic Sea, showing trophic index differences across the Adriatic coastal areas.

  8. Ground water in Utah's densely populated Wasatch Front area; the challenge and the choices

    USGS Publications Warehouse

    Price, Don

    1985-01-01

    Utah's Wasatch Front area comprises about 4,000 square miles in the north-central part of the State. In 1980, the area had a population of more than 1.1 million, or about 77 percent of Utah's total population. It contains several large cities, including Salt Lake City, Ogden, and Provo, and is commonly called Utah's urban corridor. Most of the water supply for the Wasatch Front area comes from streams that originate in the Wasatch Range and nearby Uinta Mountains; however, ground water has played an important role in the economic growth of the area. The principal source of ground water is the unconsolidated fill (sedimentary deposits) in the valleys of the Wasatch Front area--northern Juab, Utah, Goshen, and Salt Lake Valleys; the East Shore area (a valley area east of the Great Salt Lake), and the Bear River Bay area. Maximum saturated thickness of the fill in the principal ground-water reservoirs in these valleys exceeds 6,000 feet, and the estimated volume of water that can be withdrawn from just the upper 100 feet of the saturated fill is about 8 million acre-feet. In most places the water is fresh, containing less than 1,000 milligrams per liter of dissolved solids; in much of the Bear River Bay area and most of Goshen Valley (and locally in the other valleys), the water is slightly to moderately saline, with 1,000 to 10,000 milligrams per liter of dissolved solids. The principal ground-water reservoirs receive recharge at an annual rate that is estimated to exceed 1 million acre-feet--chiefly as seepage from consolidated rocks in the adjacent mountains from canals, ditches, and irrigated land, directly from precipitation, and from streams. Discharge during 1980 (which was chiefly from springs, seepage to streams, evapotranspiration, and withdrawal by wells) was estimated to be about 1.1 million acre-feet. Withdrawal from wells, which began within a few years after the arrival of the Mormon pioneers in the Salt Lake Valley in 1847, and had increased to about

  9. Sediment dispersal in the northwestern Adriatic Sea

    USGS Publications Warehouse

    Harris, C.K.; Sherwood, C.R.; Signell, R.P.; Bever, A.J.; Warner, J.C.

    2008-01-01

    Sediment dispersal in the Adriatic Sea was evaluated using coupled three-dimensional circulation and sediment transport models, representing conditions from autumn 2002 through spring 2003. The calculations accounted for fluvial sources, resuspension by waves and currents, and suspended transport. Sediment fluxes peaked during southwestward Bora wind conditions that produced energetic waves and strengthened the Western Adriatic Coastal Current. Transport along the western Adriatic continental shelf was nearly always to the south, except during brief periods when northward Sirocco winds reduced the coastal current. Much of the modeled fluvial sediment deposition was near river mouths, such as the Po subaqueous delta. Nearly all Po sediment remained in the northern Adriatic. Material from rivers that drain the Apennine Mountains traveled farther before deposition than Po sediment, because it was modeled with a lower settling velocity. Fluvial sediment delivered to areas with high average bed shear stress was more highly dispersed than material delivered to more quiescent areas. Modeled depositional patterns were similar to observed patterns that have developed over longer timescales. Specifically, modeled Po sediment accumulation was thickest near the river mouth with a very thin deposit extending to the northeast, consistent with patterns of modern sediment texture in the northern Adriatic. Sediment resuspended from the bed and delivered by Apennine Rivers was preferentially deposited on the northern side of the Gargano Peninsula, in the location of thick Holocene accumulation. Deposition here was highest during Bora winds when convergences in current velocities and off-shelf flux enhanced delivery of material to the midshelf. Copyright 2008 by the American Geophysical Union.

  10. Population parameters and mito-nuclear mosaicism of Anisakis spp. in the Adriatic Sea.

    PubMed

    Mladineo, Ivona; Bušelić, Ivana; Hrabar, Jerko; Vrbatović, Anamarija; Radonić, Ivana

    2017-03-01

    Recombinant genotypes of A. simplex sensu stricto (s.s.) and A. pegreffii, two species of Anisakis simplex complex found in sympatric waters of the Mediterranean Sea, are believed to be a product of interspecific hybridisation and/or DNA introgression. In contrast, such events within an allopatric area as the Adriatic Sea are unlikely to occur and therefore observed recombination should be assessed more closely. We have genotyped 525 anisakids collected from migratory and non-migratory fish of the southern part of the Adriatic Sea, inferring its omniparentage at nuclear (ITS locus) and matrilineage at mitochondrial locus (cox2). The aim was to address the presence and cause of the recombination within the population and to test its genetic structure under admixture theory. Population parameters, i.e. prevalence, and mean abundance and intensity of anisakids were also evaluated to contribute for future epidemiological risk assessments. As a result, we have inferred the presence of A. pegreffii, A. typica and A. ziphidarum in the Adriatic, lacking type species A. simplex s.s. at both nuclear and mitochondrial locus. A. pegreffii population shows a high level of admixture and heterogeneity and a recent demographic expansion from a small population size. We argue that the observed recombinant genotypes in the Adriatic are a product of ancestral polymorphism and consequent remote genetic introgression.

  11. Comparative growth and toxin profile of cultured Ostreopsis ovata from the Tyrrhenian and Adriatic Seas.

    PubMed

    Guerrini, Franca; Pezzolesi, Laura; Feller, Andrea; Riccardi, Manuela; Ciminiello, Patrizia; Dell'Aversano, Carmela; Tartaglione, Luciana; Dello Iacovo, Emma; Fattorusso, Ernesto; Forino, Martino; Pistocchi, Rossella

    2010-01-01

    Massive blooms of the benthic dinoflagellate Ostreopsis ovata Fukuyo have recently occurred along the whole Italian coastlines, both Tyrrhenian and Adriatic, resulting sometimes in benthonic biocenosis sufferings and, occasionally, in human health problems. In this work, two strains of O. ovata collected in 2006 along the Adriatic and Tyrrhenian coastlines and grown in culture were studied to characterize their growth and toxin profile. The two strains showed different cell volumes, the Adriatic strain being nearly twice bigger than the Tyrrhenian, but they had similar slow growth rates. Liquid chromatography-mass spectrometry (LC-MS) analyses indicated that both strains produce putative palytoxin (pPLTX) and ovatoxin-a (OVTX-a), a palytoxin-like compound presenting 2 oxygen atoms less than palytoxin. Toxin content was determined at the end of the stationary and exponential growth phases and reached the highest value in the Adriatic strain at the end of the stationary phase, with concentrations of 353.3 microg l(-1) for OVTX-a and 30.4 microg l(-1) for pPLTX. Toxin released in the growth medium was also measured and resulted to be the highest at the end of the stationary phase, suggesting that a long lasting bloom could enhance the toxin content in the water and cause toxic effects in people inhaling the aerosol.

  12. Fault-plane Solutions Determined by Waveform Modeling Confirm Tectonic Collision in the Eastern Adriatic

    NASA Astrophysics Data System (ADS)

    Louvari, E.; Kiratzi, A.; Papazachos, B.; Hatzidimitriou, P.

    - Source parameters for thirteen earthquakes in the SE Adriatic region have been determined using P and SH body-waveform inversion. The results of this modeling are combined with eleven other earthquakes with M>=5 whose focal mechanisms have been determined mainly by waveform modeling. The results confirm that movement on mainly low-angle reverse faults causes the deformation in coastal southern Yugoslavia through Albania up to the Lefkada Island in NW Greece. This zone of thrusting has a NW-SE trend (N34°W), follows the coastline, and dips towards the continent. The slip vectors of these events trend at N229° along the Dalmatian coasts, to N247° along Albania and NW Greece. The deformation is attributed to the continental collision between the Adriatic block to the west and Eurasia to the east. Along the mountain line in eastern Albania (Albanides Mts.) and in NW Greece (Hellenides Mts.), E-W extension is occurring. The E-W extension associated with the orogenic belt could be attributed to a variety of models such as: gravity, internal deformation of the thrust wedge, a probable down bulge of the dense lithosphere of the Adriatic block beneath the Eurasian lithospheric plate in combination with the compressional stresses applied along the collision belt.

  13. Footprints of mesoscale eddy passages in the Strait of Otranto (Adriatic Sea)

    NASA Astrophysics Data System (ADS)

    Ursella, Laura; KovačEvić, Vedrana; GačIć, Miroslav

    2011-04-01

    The footprints of mesoscale eddies propagating through the Strait of Otranto are documented from current meter records, and their formation mechanism is hypothesized. Bottom-mounted Acoustic Doppler Current Profilers data, collected during 5 months (November 2006 through April 2007) at a transect in the core of the outflowing Adriatic Dense Water, reveal energetic events that manifest as vertically uniform current vector rotations on a time scale of about 10 days. At the two moorings close to the center of the strait, coherent current vector rotations were in opposite senses. Simulation of the passage of an idealized cyclonic or anticyclonic rigid circular eddy confirms that these opposed rotations could be associated with passages of eddies in the southward direction. Characteristic parameters of the eddies were estimated: the duration was several days, the peak azimuthal velocity was around 10-20 cm/s, and advection velocity below 15 cm/s was predominantly in the southwestward direction. Cyclones were bigger (diameter 30-36 km) than anticyclones (14-24 km), and they traveled at greater depths. The eddy passage left a prominent signal in the thermohaline and turbidity properties. This latter is probably due to sediment resuspension by strong currents and to the advection of the suspended particles through an upstream located canyon. The eddy formation is explained in terms of stretching of the high potential vorticity water column outflowing the Strait of Otranto, a mechanism similar to that observed in the Denmark Strait overflow. Another possible explanation is the baroclinic instability of the overflow layer which results in the eddy formation.

  14. Transparent and Dense Ladder-Like Alkylene-Bridged Polymethylsiloxane Coating with Enhanced Water Vapor Barrier Property.

    PubMed

    Zhang, Ce; Zhang, Cong; Cui, Xinmin; Sun, Jinghua; Ding, Ruimin; Zhang, Qinghua; Xu, Yao

    2015-10-14

    Organic-inorganic hybrid composites have been well-studied as water vapor barrier materials for their long diffusion length of water vapor in coatings which can be realized by improving the aspect ratio of inorganic components and regularity of nanostructure in coatings. In this paper, dense organic-inorganic hybrid coating based on ladder-like alkylene-bridged polymethylsiloxane (ABPMS) was successfully fabricated through the hydrosilylation reaction between polymethylhydrosiloxane and diene (1,5-hexadiene or 1,7-octadiene) in toluene under Pt/C catalysis. Its ladder-like structure was verified by 29Si magic angle spinning (MAS) NMR, 13C MAS NMR, and in-plane and out-of-plane glance-incident X-ray diffraction (GIXRD) techniques. Its corresponding coating showed excellent water vapor barrier ability for a typical water-soluble crystal, potassium dihydrogen phosphate (KDP). When treated in 50% relative humidity (RH) condition at 25 °C for 8 months, the ABPMS coating with 100 nm thickness displayed a very low transmittance loss of 1.6% compared with the high transmittance loss of 10% for uncoated KDP. Moreover, the ABPMS coating showed good ultraviolet radiation resistance, thermal stability, low mechanical property, and excellent compatibility with hydrophobic antireflective (AR) coatings.

  15. Dense Semi-Clathrates at High Pressure: A Study of the Water-tert-Butylamine System.

    PubMed

    Granero-García, Rubén; Falenty, Andrzej; Fabbiani, Francesca P A

    2017-03-13

    In situ high-pressure crystallization and diffraction techniques have been applied to obtain two very structurally distinct semi-clathrates of the tert-butylamine-water system with hydration numbers 5.65 and 5.8, respectively, thereby considerably reducing a notable hydration gap between the monohydrate and the 71/4 -hydrate that results when crystallization space is explored by temperature alone. Both structures can be considered as an intriguing solid-state example of hydrophobic hydration, in which the water network creates wide tert-butylamine-filled channels stabilized by cross-linking hydrogen bonds. The existence of interconnected channels might also add low hydration structures to a list of potential targets for hydrogen storage. A detailed analysis of the topology of host water and host-guest interactions is reported and extended to those of other hydrates of the compound. This analysis offers new insight into properties of the tert-butylamine-water system and provides some clues as to the occurrence of the sizable number of hydrates of this compound.

  16. Modeling the influence of climate change on the mass balance of polychlorinated biphenyls in the Adriatic Sea.

    PubMed

    Lamon, Lara; MacLeod, Matthew; Marcomini, Antonio; Hungerbühler, Konrad

    2012-05-01

    Climate forcing is forecasted to influence the Adriatic Sea region in a variety of ways, including increasing temperature, and affecting wind speeds, marine currents, precipitation and water salinity. The Adriatic Sea is intensively developed with agriculture, industry, and port activities that introduce pollutants to the environment. Here, we developed and applied a Level III fugacity model for the Adriatic Sea to estimate the current mass balance of polychlorinated biphenyls in the Sea, and to examine the effects of a climate change scenario on the distribution of these pollutants. The model's performance was evaluated for three PCB congeners against measured concentrations in the region using environmental parameters estimated from the 20th century climate scenario described in the Special Report on Emission Scenarios (SRES) by the IPCC, and using Monte Carlo uncertainty analysis. We find that modeled fugacities of PCBs in air, water and sediment of the Adriatic are in good agreement with observations. The model indicates that PCBs in the Adriatic Sea are closely coupled with the atmosphere, which acts as a net source to the water column. We used model experiments to assess the influence of changes in temperature, wind speed, precipitation, marine currents, particulate organic carbon and air inflow concentrations forecast in the IPCC A1B climate change scenario on the mass balance of PCBs in the Sea. Assuming an identical PCBs' emission profile (e.g. use pattern, treatment/disposal of stockpiles, mode of entry), modeled fugacities of PCBs in the Adriatic Sea under the A1B climate scenario are higher because higher temperatures reduce the fugacity capacity of air, water and sediments, and because diffusive sources to the air are stronger.

  17. The origin of Messinian canyons in the Mediterranean: the role of brine-related dense shelf water cascading currents

    NASA Astrophysics Data System (ADS)

    Roveri, Marco; Bergamasco, Andrea; Marcello Falcieri, Francesco; Gennari, Rocco; Lugli, Stefano; Manzi, Vinicio; Schreiber, B. Charlotte

    2013-04-01

    Recent studies on modern deep-sea environments have documented the role of submarine processes, such as turbidity currents, fluvial flood-related hyperpycnal flows and dense shelf water cascading (DSWC), in the genesis and evolution of canyons and gullies. These processes are largely independent from sea-level fluctuations and significant erosion has been shown to occur even at present-day sea-level highstand conditions. The study of ancient deep-marine environments and processes may take great advantage from the knowledge produced during the last decade in this field of research. The study of some exceptional events of the past is an exciting issue for a common effort of specialists from different disciplines (geomorphology, geology, physical oceanography) in the understanding of modern and ancient deep seascape. An example is provided by the genesis of the widespread Messinian erosional surface (MES) and the associated gullies and canyons, which have been recognized through seismic data along the Mediterranean shelves and slopes. These features are commonly related to subaerial fluvial processes that imply a 1500 m drawdown and the desiccation of the Mediterranean Sea during what has been called the "Messinian salinity crisis" (MSC). Such an interpretation is one of the main arguments for the shallow-water deep-basin model (Hsü et al., 1973), which is the current paradigm for the MSC. However, no unquestionable evidence for subaerial deposits associated with the MES has been ever documented. We suggest that fully submarine erosional processes played a significant role in shaping the Mediterranean slopes also during the MSC; thus, no desiccation is needed to explain canyon formation and/or rejuvenation. We want to stress here the importance of the processes, driven by evaporative fluxes in shallow areas, that lead to the formation of seasonal high-density contrasts and cause the development of cascading along the continental slopes (Shapiro et al., 2003). These

  18. Dense Breasts

    MedlinePlus

    ... fatty tissue. On a mammogram, fatty tissue appears dark (radio-lucent) and the glandular and connective tissues ... white on mammography) and non-dense fatty tissue (dark on mammography) using a visual scale and assign ...

  19. On the Boundary Condition for Water at a Hydrophobic, Dense Surface

    NASA Technical Reports Server (NTRS)

    Walther, J. H.; Jaffe, R. L.; Werder, T.; Halicioglu, T.; Koumoutsakos, P.

    2002-01-01

    We study the no-slip boundary conditions for water at a hydrophobic (graphite) surface using non-equilibrium molecular-dynamics simulations. For the planar Couette flow, we find a slip length of 64 nm at 1 bar and 300 K, decreasing with increasing system pressure to a value of 31 nm at 1000 bar. Changing the properties of the interface to from hydrophobic to strongly hydrophilic reduces the slip to 14 nm. Finally, we study the flow of water past an array of carbon nanotubes mounted in an inline configuration with a spacing of 16.4 x 16.4 nm. For tube diameters of 1.25 and 2.50 nm we find drag coefficients in good agreement with the macroscopic, Navier-Stokes values. For carbon nanotubes, the no-slip condition is valid to within the definition of the position of the interface.

  20. On the Impacts of Different Surface Forcing Regimes for Deep Water Formation in the Mediterranean Sea

    NASA Astrophysics Data System (ADS)

    Josey, S.; Tsimplis, M.; Gomis, D.; Ruiz, S.; Marcos, M.; Somot, S.

    2009-04-01

    Deep water formation is known to occur at 3 major sites (the Gulf of Lions, Adriatic and Aegean Seas) in the Mediterranean basin. However, the role played by air-sea interaction in setting the frequency and strength of formation events (including major transient episodes such as that experienced in the Aegean sea in the early 1990s) is not well understood. We will explore this relationship using air-sea heat, freshwater and density flux fields, including output from downscaled versions (HIPOCAS and ARPERA) of the NCEP/NCAR and ECMWF reanalyses. The downscaled fields reveal small scale forcing features (including jet-like structures over the dense water formation sites) that are not present in the coarser resolution reanalysis datasets. They also show greater variability in the forcing of the Aegean and the Gulf of Lions than the Adriatic Sea. The differences between the forcing distributions of the Aegean and Adriatic will be discussed in detail and will be advanced as a potential cause for variations in frequency of dense water formation in these two regions.

  1. Dissolution-induced contact angle modification in dense nonaqueous phase liquid/water systems.

    PubMed

    Mohammad, Orphius I; Kibbey, Tohren C G

    2005-03-15

    The contact angle between DNAPL, water, and aquifer material interfaces influences the spatial distribution of DNAPLs as they infiltrate into the aquifer, and may ultimately influence their remediation. The objective of this work was to evaluate the effects of dissolution on contact angle. Just as physically retracting a sessile drop reduces its contact angle with a surface, it was speculated that dissolution could cause contact angles to be reduced. Long-term dissolution experiments were conducted over the course of days to weeks, examining the dissolution of sessile drops of two DNAPLs, trichloroethylene (TCE) and tetrachloroethylene (PCE), in water and low concentration surfactant solutions, on glass surfaces. Experiments found that dissolution led to a continuous decrease of contact angle measured through the DNAPL drop, in most cases to near 0 degrees, far lower than angles achievable through measurements of receding contact angles for the same systems. Pinning of drop contact diameter was observed in most experiments. A model developed on the basis of the Bashforth-Adams equation to predict the effect of dissolution on contact angle for drops with a pinned contact diameter showed very good agreement with experimental observations.

  2. The role of forcing agents on biogeochemical variability along the southwestern Adriatic coast: The Gulf of Manfredonia case study

    NASA Astrophysics Data System (ADS)

    Specchiulli, Antonietta; Bignami, Francesco; Marini, Mauro; Fabbrocini, Adele; Scirocco, Tommaso; Campanelli, Alessandra; Penna, Pierluigi; Santucci, Angela; D'Adamo, Raffaele

    2016-12-01

    This study investigates how multiple forcing factors such as rivers, surface marine circulation and winds affect hydrology and biogeochemical processes in the Gulf of Manfredonia and the seas around the Gargano peninsula, in the south-western Adriatic Sea. The study adopted an integrated approach, using in situ and remote sensing data, as well as the output of current models. The data reveal variability in the area's hydrography induced by local freshwater sources, the Western Adriatic Current (WAC) flowing from the north along the Italian coast, and the current patterns under different wind regimes. Specifically, exchange with offshore waters in the gulf induces variability in salinity and biogeochemical content, even within the same season, i.e. winter, in our case. This strong dependence on physical and biogeochemical factors makes the Manfredonia-Gargano ecosystem vulnerable to climate change, which could compromise its important role as a nursery area for the Adriatic Sea.

  3. High resolution modelling of dense water formation in the Northwestern Mediterranean: benefits from an improved initial stratification in summer

    NASA Astrophysics Data System (ADS)

    Estournel, Claude; Testor, Pierre; Damien, Pierre; Mortier, Laurent; Marsaleix, Patrick; Lellouche, Jean-Michel; Ulses, Caroline; Kessouri, Faycal; Raimbault, Patrick; Coppola, Laurent

    2014-05-01

    The period that extends from summer 2012 to summer 2013 was the subject of several field campaigns in the northwestern Mediterranean that allowed to characterize the stratification on a seasonal scale in this region of deep water formation. This period is therefore ideal for testing hydrodynamic models and assessing the accuracy required on initial conditions and meteorological forcing. A 1 km resolution simulation of the vertical stratification evolution of the northwestern Mediterranean between summer 2012 and spring 2013 was conducted. The representation of winter convection was shown to be highly dependent on initial conditions in summer. A method was developed to correct the initial state of the model using the observations of the annual summer cruise of the MOOSE monitoring program and data from ARGO profilers. In addition, an adjustment of the wind helped to better approach winter observations, the criterion being the profile of residual buoyancy, simple index of the potential of the water column to convect more or less deeply and rapidly. The simulation obtained after correction of the initial conditions and wind forcing allowed to accurately represent the characteristics of the water masses formed during the convective period, the area concerned by convection and its timing. We will first present the methodology used to correct the initial state of the simulation, and then the validation of the simulation based on the observations from the DEWEX cruise (MERMEX program) and from profilers deployed in the frame of the HyMeX program. Then the volume of dense water formed and its characteristics will be quantified as well as their sensitivity to initial conditions.

  4. Interaction between colloidal particles on an oil-water interface in dilute and dense phases.

    PubMed

    Parolini, Lucia; Law, Adam D; Maestro, Armando; Buzza, D Martin A; Cicuta, Pietro

    2015-05-20

    The interaction between micron-sized charged colloidal particles at polar/non-polar liquid interfaces remains surprisingly poorly understood for a relatively simple physical chemistry system. By measuring the pair correlation function g(r) for different densities of polystyrene particles at the decane-water interface, and using a powerful predictor-corrector inversion scheme, effective pair-interaction potentials can be obtained up to fairly high densities, and these reproduce the experimental g(r) in forward simulations, so are self consistent. While at low densities these potentials agree with published dipole-dipole repulsion, measured by various methods, an apparent density dependence and long range attraction are obtained when the density is higher. This condition is thus explored in an alternative fashion, measuring the local mobility of colloids when confined by their neighbors. This method of extracting interaction potentials gives results that are consistent with dipolar repulsion throughout the concentration range, with the same magnitude as in the dilute limit. We are unable to rule out the density dependence based on the experimental accuracy of our data, but we show that incomplete equilibration of the experimental system, which would be possible despite long waiting times due to the very strong repulsions, is a possible cause of artefacts in the inverted potentials. We conclude that to within the precision of these measurements, the dilute pair potential remains valid at high density in this system.

  5. Estimates of the hydrologic impact of drilling water on core samples taken from partially saturated densely welded tuff

    SciTech Connect

    Buscheck, T.A.; Nitao, J.J.

    1987-09-01

    The purpose of this work is to determine the extent to which drill water might be expected to be imbibed by core samples taken from densely welded tuff. In a related experimental study conducted in G-Tunnel, drill water imbibition by the core samples was observed to be minimal. Calculations were carried out with the TOUGH code with the intent of corroborating the imbibition observations. Due to the absence of hydrologic data pertaining directly to G-Tunnel welded tuff, it was necessary to apply data from a similar formation. Because the moisture retention curve was not available for imbibition conditions, the drainage curve was applied to the model. The poor agreement between the observed and calculated imbibition data is attributed primarily to the inappropriateness of the drainage curve. Also significant is the value of absolute permeability (k) assumed in the model. Provided that the semi-log plot of the drainage and imbibition moisture retention curves are parallel within the saturation range of interest, a simple relationship exists between the moisture retention curve, k, and porosity ({phi}) which are assumed in the model and their actual values. If k and {phi} are known, we define the hysteresis factor {lambda} to be the ratio of the imbibition and drainage suction pressures for any saturation within the range of interest. If k and {phi} are unknown, {lambda} also accounts for the uncertainties in their values. Both the experimental and modeling studies show that drill water imbibition by the core has a minimal effect on its saturation state. 22 refs., 6 figs., 2 tabs.

  6. GCM studies of intermediate and deep waters in the Mediterranean

    NASA Astrophysics Data System (ADS)

    Haines, Keith; Wu, Peili

    1998-12-01

    Results from GCM simulations of the Mediterranean thermohaline circulation are presented under repeating year wind and surface buoyancy forcings and the reproduction of important physical processes is discussed. It is shown that baroclinic eddies are critical to the effective dispersal of Levantine intermediate water (LIW) throughout the eastern Mediterranean basin. These develop rapidly even in a 1/4 degree model which does not resolve the deformation radius, provided horizontal friction is small enough. It is shown that LIW enters the Adriatic basin and pre-conditions deep water formation which would not otherwise occur due to low surface salinity in winter. The dispersal of Adriatic deep waters is modelled, and it is shown that the introduction of the Gent and McWilliams advective scheme greatly improves the distribution of deep waters in the eastern basin by permitting the formation of dense overflow waters from the Otranto straits. This is achieved with very small parametrised advection that still permits the formation of baroclinic eddies unlike most applications which use the scheme to replace eddies. Results from a 100-year climate simulation are then presented in which the thermohaline circulation has reached equilibrium conditions. Dense water formation in both eastern and western basin still occur after 100 years. While the eastern basin water masses are reasonably realistic, the western basin is a little too cold and fresh, suggesting that insufficient LIW is reaching the deep water formation site in the northwest basin. Further work is needed in this area.

  7. Exceptional Bora outbreak in winter 2012: Validation and analysis of high-resolution atmospheric model simulations in the northern Adriatic area

    NASA Astrophysics Data System (ADS)

    Davolio, Silvio; Stocchi, Paolo; Benetazzo, Alvise; Bohm, Emanuele; Riminucci, Francesco; Ravaioli, Mariangela; Li, Xiao-Ming; Carniel, Sandro

    2015-09-01

    The Bora wind event occurred in winter 2012 was exceptional in terms of both meteorological effects and impact on the Adriatic Sea circulation. It was associated with intense and persistent winds, very cold temperatures all over the Mediterranean basin and heavy snowfall over the Apennines slopes exposed to north-easterly winds, and it was responsible for triggering dense water formation and driving basin-scale oceanic circulation. The cooling period (29 January-13 February) was characterized by intense air-sea exchanges of momentum and heat, whose accurate simulation is required for a proper description of atmospheric and ocean circulations. In the present study, results of a number of short-range high-resolution numerical weather prediction (NWP) model simulations for the entire Bora outbreak are discussed. The modeling chain, based on BOLAM and MOLOCH limited area models, has been implemented using initial and boundary conditions provided by different global NWP systems. Model performance has been evaluated in terms of variables of interest for oceanographic applications, such as sea surface temperature (SST), surface heat fluxes, solar radiation and near surface meteorological parameters (air temperature, wind, pressure and humidity). The validation has been undertaken through a comparison against surface data (buoys and oceanographic platforms) available at different locations in the northern Adriatic area, while advanced synthetic aperture radar (ASAR) products have been used to assess modeled wind fields on a larger scale. Model results indicate a good agreement with the observations concerning meteorological variables, in particular wind, pressure and temperature. However, large differences were found in the SST forecasts, which in turn affect also sea surface flux predictions. The uncertainties in SST forecasts are mainly ascribable to the different initialization fields provided by either the global models or satellite analyses. Thus SST initialization

  8. Adriatic and Black Sea level in the 20th century and projection to the end of the 21st century.

    NASA Astrophysics Data System (ADS)

    Scarascia, Luca; Lionello, Piero

    2015-04-01

    Adriatic and Black Sea are semi-enclosed basins characterized by densely populated coasts, industrial compounds and a rich cultural and historical heritage. It appears to be crucial, for the management and the protection of their coastlines, to understand how much they will be impacted by the global sea level (SL) rise, projected by the end of this century. The aim of this work is to develop a method that allows to estimate to which extent the SL of the two basins will depart from the mean global level. The future evolution of global sea level is not a meaningful indicator at this regional scale and past deviations, due to local factors of the Adriatic and Black Sea levels from the global one, have been observed. The Adriatic Sea is the basin of the Mediterranean Sea best covered by past SL observations. In fact, for the Adriatic Sea is possible to obtain, by statistical method based on PCA and Least square Method, a seamless and long time series (from 1900 to 2009) using records of 7 mareographic stations located along the Italian and Croatian coasts (from PSMSL database). Satellite data of SL are available for the whole Mediterranean from 1993 to 2012 and they show a very high correlation (rho > 0.9) with Adriatic time series based on mareographic records. The SL time series of the 20th century in the Black Sea is computed using data of 4 stations, which are available in the PSMSL (Permanent Service for Mean Sea Level) archive, located on the north-east coast. This time series shows a lower correlation (rho about 0.5) with satellite data than in the case of Adriatic Sea. Further it shows a higher interannual variability. All the time series are considered after the subtraction of the Inverse Barometer (IB) effect. A statistical approach, based on a multivariate linear regression model, is used to investigate the link between SL anomaly, computed as the difference between the regional SL and global SL, and three large scale climate variables (sea level pressure

  9. Estimating dense water volume and its evolution for the year 2012-2013 in the Northwestern Mediterranean Sea: An observing system simulation experiment approach

    NASA Astrophysics Data System (ADS)

    Waldman, Robin; Somot, Samuel; Herrmann, Marine; Testor, Pierre; Estournel, Claude; Sevault, Florence; Prieur, Louis; Mortier, Laurent; Coppola, Laurent; Taillandier, Vincent; Conan, Pascal; Dausse, Denis

    2016-09-01

    The Northwestern Mediterranean (NWMed) Sea includes one of the best observed ocean deep convection sites in the World. An observing system simulation experiment (OSSE) is developed to provide a methodology for estimating observing network errors. It is applied to quantify dense water volumes in the NWMed during 2012-2013 with their observation error from MOOSE network. Results from the OSSE show low spatiotemporal sampling errors, which confirms MOOSE network ability to measure dense waters. However, results are highly sensitive to instrumental stability. The dense water volume is then estimated in observations from four ship cruises between summers 2012 and 2013. A large seasonal cycle is found, maximal in spring 2013 and dominated by the area west of 6.5°E. The dense water volume (σ0>29.11 kg/m3) is stable between summer 2012 (13.3±0.6 × 1013 m3) and winter 2013 (13.7±1.3 × 1013 m3). It increases dramatically in spring 2013 (17.7±0.9 × 1013 m3) due to an intense convective event, and it finally decreases rapidly in summer 2013 (15.1±0.6 × 1013 m3) due to restratification and spreading. We estimate an open-sea dense water formation (DWF) rate of 1.4±0.3 Sv between summer 2012 and spring 2013 over the studied area, extrapolated to 2.3±0.5 Sv over the whole NWMed Sea and for the optimal timing. This is to our knowledge the highest measured DWF rate, suggesting winter 2013 was exceptionally convective. The observed restratification rate between spring and summer 2013 is -0.8±0.4 Sv. This study provides robust quantifications of deep convection during an exceptional event that will allow to evaluate numerical simulations.

  10. Eutrophication in the northern Adriatic Sea: Benthic fluxes and nutrient budgets

    SciTech Connect

    Berelson, W.M.; Hammond, D.E. ); Giordani, P. )

    1990-01-09

    The northern Adriatic Sea has been plagued by problems of eutrophication. This area is relatively shallow (maximum depth = 60m), becoming stratified during the summer months which inhibits oxygen transport to bottom waters. Anthropogenic nutrient loading in rivers entering the northern Adriatic has increased nutrient input to this system and stimulated algai growth. Five stations in the western Adriatic (south of the Po River Delta) were occupied during September, 1988 and benthic flux chambers used to measure nutrient fluxes. These sites included 3 stations previously studied in 1982. Flux measurements of dissolved silica, nitrate, oxygen, ammonia, phosphate, CO[sub 2], alkalinity and radon were made during 24 hour incubations of flux chambers (area covered - 0.07 m[sup 2], volume = [approximately]81) that were continuously stirred and sampled periodically. Nutrient fluxes measured were generally consistent with the fluxes measured previously in June, 1982 except for radon fluxes which were 203 times greater in the earlier field season. There was a general trend in nutrient fluxes to decrease offshore, a pattern probably controlled by the sedimentation patterns because fine grained, organic matter-rich sediment are concentrated in a zone near shore. Average regional fluxes were (in mmol m[sup -2]d[sup -1], negative values indicate flux into sediment): Oxygen (-12), CO[sub 2] (19), Alkalinity (4), Silica (3.3), Ammonia (1.5), Phosphate (0.1) and Nitrate (0.3). The carbon/ammonia flux ratio is about twice the C/N ratio in marine phytoplankton, suggesting that large amounts of denitrification may be occuring in these sediments. Comparisons of benthic fluxes and sediment burial rates indicate that 50-90% of the carbon, silica, phosphorus and nitrogen arriving at the sediment-water interface is recycled before burial. The nutrient input to the water column from NW Adriatic sediments is about equal to the input from coastal rivers.

  11. Geochemistry of sediments in the Northern and Central Adriatic Sea

    NASA Astrophysics Data System (ADS)

    De Lazzari, A.; Rampazzo, G.; Pavoni, B.

    2004-03-01

    Major, minor and trace elements, loss of ignition, specific surface area, quantities of calcite and dolomite, qualitative mineralogical composition, grain-size distribution and organic micropollutants (PAH, PCB, DDT) were determined on surficial marine sediments sampled during the 1990 ASCOP (Adriatic Scientific Cooperative Program) cruise. Mineralogical composition and carbonate content of the samples were found to be comparable with data previously reported in the literature, whereas geochemical composition and distribution of major, minor and trace elements for samples in international waters and in the central basin have never been reported before. The large amount of information contained in the variables of different origin has been processed by means of a comprehensive approach which establishes the relations among the components through the mathematical-statistical calculation of principal components (factors). These account for the major part of data variance loosing only marginal parts of information and are independent from the units of measure. The sample descriptors concerning natural components and contamination load are discussed by means of a statistical model based on an R-mode Factor analysis calculating four significant factors which explain 86.8% of the total variance, and represent important relationships between grain size, mineralogy, geochemistry and organic micropollutants. A description and an interpretation of factor composition is discussed on the basis of pollution inputs, basin geology and hydrodynamics. The areal distribution of the factors showed that it is the fine grain-size fraction, with oxides and hydroxides of colloidal origin, which are the main means of transport and thus the principal link between chemical, physical and granulometric elements in the Adriatic.

  12. Underwater noise assessment in the Gulf of Trieste (Northern Adriatic Sea, Italy) using an MSFD approach.

    PubMed

    Codarin, Antonio; Picciulin, Marta

    2015-12-30

    In the marine environment, underwater noise is one of the most widespread input of man-made energy. Recently, the European Commission has stressed the necessity of establishing threshold levels as a target for the descriptor 11.2.1 "Continuous low frequency sounds" in the Marine Strategy Framework Directive (MSFD). In 2012, a monthly underwater noise monitoring programme was conducted in the Gulf of Trieste (Northern Adriatic Sea, Italy); the collected acoustic samples (frequency range: 10-20,000 Hz) were analysed in the 1/3 octave bands. The stations have been further clustered following the 63 and 125 Hz bands noise levels. Average SPL levels resulted similar to those previously computed for proximate areas, indicating that the Adriatic Sea sub-region experiences high noise pressure in the marine waters. In its turn this claims for a scientific and technical international cooperation, as requested by the EU programme. No seasonal variation in local noise levels has been found.

  13. Eulerian current measurements in the Strait of Otranto and in the Southern Adriatic

    NASA Astrophysics Data System (ADS)

    Kovačević, Vedrana; Gačić, Miroslav; Poulain, Pierre-Marie

    1999-04-01

    The main features of the mean flow across the Strait of Otranto are studied using long-term (2-years) direct current measurements. The flow is characterized by a cyclonic horizontal shear between the inflowing currents from the Ionian into the Adriatic to the east and the outflowing currents from the Adriatic into the Ionian to the west, and by a two-layer structure in the central region, where in the bottom layers Adriatic Deep Water (ADW) outflows into the Ionian. The currents were also measured in the Southern Adriatic during summer. These data reveal the cyclonic circulation around the South Adriatic Pit, while the flow over the Otranto Sill has a two-layer structure with inflow near the surface and outflow near the bottom. The subtidal flow variability across the Strait of Otranto during winter, summer, and autumn is also analyzed. The space-time structures of the flow are obtained using an Empirical Orthogonal Function (EOF) analysis. It is shown that in winter and autumn the greatest portion of the current variance is associated with the intense fluctuations in the upper layers along the strait flanks. This subtidal variability is superimposed over the outflow along the western shelf and over the inflow along the eastern strait margin, with a time scale on the order of 10 days. The fluctuations are mostly driven by the local north-south winds, which through the Ekman transport and consequent geostrophic adjustments modulate the mean circulation. The barotropic-like flow fluctuations trapped over the western continental slope, with the intensification in the ADW layer, are prominent in summer, probably because the intensity of the wind-forced fluctuations along the strait flanks is attenuated. This barotropic-like pattern seems to modulate ADW outflow, blocking it completely from time to time. From the presently available data sets the main force driving these fluctuations has not been identified. However, they are partially associated with the barotropic

  14. A sea of worms: polychaete checklist of the Adriatic Sea.

    PubMed

    Mikac, Barbara

    2015-04-07

    The checklist of polychaetes of the Adriatic Sea (Mediterranean) based on bibliographic sources published from 1840 to 2014, as well as on novel data, with 49 new records for the area, is herein presented. The Adriatic Sea polychaete fauna comprises at present of 764 species in 360 genera and 62 families. The richest family is the Syllidae, with 112 species (c.a. 15% of the all taxa). Eight families account for as much as 50% of the diversity (Syllidae, Serpulidae, Sabellidae, Phyllodocidae, Spionidae, Polynoidae, Terebellidae and Nereididae). Among the three Adriatic sectors (Northern, Central and Southern Adriatic), the Northern Adriatic is the richest one, whereas the composition of the most diverse families is very similar in all sectors. Data on endemisms (6), aliens (29) and valid species with the type locality in the Adriatic Sea (90) are also discussed. The list of all relevant papers citing each species in the Adriatic is included, allowing future detailed information retrievals for distinct purposes. Results suggest that the number of species will keep increasing in the future, as new surveys will be undertaken, so regular updates of the present list will be necessary.

  15. Seabed litter composition, distribution and sources in the Northern and Central Adriatic Sea (Mediterranean).

    PubMed

    Pasquini, Giulia; Ronchi, Francesca; Strafella, Pierluigi; Scarcella, Giuseppe; Fortibuoni, Tomaso

    2016-12-01

    Detecting the origin of marine benthic litter is fundamental for developing policies aimed at achieving the Good Environmental Status in European Seas by 2020, as requested by the Marine Strategy Framework Directive (MSFD). The abundance and composition of benthic litter in the Northern and Central Adriatic Sea were investigated at 67 stations with bottom trawl nets. Average density of benthic litter was 913±80items/km(2), ranking the Adriatic as one of the most polluted basins worldwide. Plastic was dominant in terms of numbers (80%) and weight (62%), and mainly consisted in bags, sheets and mussel nets. Higher quantities of litter were found in coastal areas, especially in front river mouths, coastal cities and mussel farms. In deep waters, litter hotspots were associated with most congested shipping lanes, indicating an additional litter input to the basin. Benthic litter composition resulted to be largely driven by the vicinity to local sources, i.e. mussel farming installations and most congested shipping routes. These findings provide useful insights to set measures to manage marine litter in the Adriatic region, and possibly to minimize this anthropogenic pollution.

  16. Molluscan shell communities: a window into the ecological history of the northern Adriatic Sea

    NASA Astrophysics Data System (ADS)

    Gallmetzer, Ivo; Haselmair, Alexandra; Tomasovych, Adam; Stachowitsch, Michael; Zuschin, Martin

    2015-04-01

    The historical ecology approach used in the present study sheds light on the younger ecological history of the northern Adriatic Sea, targeting the period of the last 500 to 1500 years. We focus on down-core changes in molluscan death assemblages, where differences between community structures serve as a proxy for ecological shifts over time. The northern Adriatic Sea, with its densely populated shoreline, is among the most degraded marine ecosystems worldwide and is therefore particularly suited to study ecosystem modification under human pressure. Multiple cores of 1.5 m length and diameters of 90 and 160 mm were taken at seven sampling stations throughout the northern Adriatic Sea, covering different sediment types, nutrient conditions and degrees of exploitation. For the mollusc analyses, the cores were sliced into smaller subsamples and analysed for species composition, abundance, taxonomic similarity, evidence for ecological interactions (i.e., frequencies of drilling predation) and taphonomic condition of shells. Sediment analyses include granulometry and radiometric sediment dating using Pb 210. Sediment age analysis revealed one-order-of-magnitude differences in sedimentation rates between stations (34 mm/yr at the Po delta, Italy, 1.5 mm/yr at Brijuni islands, Croatia). In total, 114 bivalve and 112 gastropod species were recorded. Bivalve assemblages showed significant interregional differences that are strongly correlated with sedimentation rates and sediment composition. Down-core changes in molluscan communities are conspicuous in all cores, particularly in the uppermost core sections. This information, together with radiometric shell dating for selected species, helps to specify the timing of major ecological changes in the past and define pristine benthic communities as references for future conservation and management efforts.

  17. Recurrent intrusions of transitional waters of Eastern Mediterranean origin in the Cretan Sea as a tracer of Aegean Sea dense water formation events

    NASA Astrophysics Data System (ADS)

    Velaoras, Dimitris; Krokos, George; Theocharis, Alexander

    2015-06-01

    Available temperature and salinity data in the Cretan Sea from 1955 up to 2014 as well as literature sources were revisited in order to trace the appearance of low salinity, temperature, oxygen and nutrient-rich waters inside the basin at depths below the intermediate layer. First appearing as far back as 1961 in literature, these waters were found originating in the layers that separate intermediate and deep waters of the Eastern Mediterranean Sea (EMed) and were named Transitional Mediterranean Water (TMW) in the 1990s. Data analysis showed that the appearance of TMW in the Cretan Sea is a recurrent phenomenon connected to water mass exchanges between the Aegean Sea and the EMed. In particular, the inflow of TMW in the Cretan basin acts as compensation for the outflow of equally dense or denser masses from the Aegean. This export is a result of dense water formation (DWF) events taking place inside the Aegean Sea triggering TMW compensatory inflow into the Cretan Sea through the Cretan Straits. In this context, TMW intrusions in the Cretan basin can be used as a tracer of DWF in the Aegean Sea while the depth of the intrusion can provide valuable information about the intensity of the DWF event. The importance of TMW intrusions is not solely restricted to the tracing and evaluation of DWF events but could additionally expand to the impact on local ecological processes as TMW is a nutrient carrier for the oligotrophic Cretan Sea. It is obvious that this low salinity, temperature and oxygen layer is what was later named TMW. The core temperature, salinity and oxygen values reported by Miller (1974) fall within the range of values observed during the PELAGOS project in 1994, as noted in Section 'Presence of low salinity water masses below the intermediate layer in the Cretan Sea during the EMT event'. Using the same dataset provided by MEDATLAS 2002 database, a salinity transect along the Cretan Sea is reconstructed in Fig. 5. The bottle data originate from the

  18. Factors favouring large organic production in the northern Adriatic: towards the northern Adriatic empirical ecological model

    NASA Astrophysics Data System (ADS)

    Kraus, R.; Supić, N.; Precali, R.

    2015-06-01

    Influenced by one of the largest Mediterranean rivers, Po, the northern Adriatic production is highly variable seasonally and interannually. The changes are especially pronounced between winters and seemingly reflect on total Adriatic bioproduction of certain species (anchovy). We analysed the long-term changes in the phytoplankton production at the transect in the region, as derived from monthly oceanographic cruises, in relation to concomitant geostrophic currents distribution in the area and in the Po River discharge rates in days preceding the cruises. In winter and early spring the phyto-abundances depended on existing circulation fields, in summer and autumn they were related to 1-15 days earlier Po River discharge rates and on concomitant circulation fields, while in late spring phyto-abundances increased 1-3 days after high Po River discharge rates regardless of circulation fields. During the entire year the phyto-abundances were dependant on forcing of the previous 1-12 months of surface fluxes and/or Po River rates. Large February blooms are, as well as February circulation patterns, precondited by low evaporation rates in previous November. From 1990 to 2004 a shift towards large winter bioproduction induced by circulation changes appeared. Performed investigations represent the preliminary actions in building of an empirical ecological model of the northern Adriatic which can be used in the sustainable economy of the region, however also in validation of the numerical ecological model of the region, which is currently being developed.

  19. Gradients of benthic pelagic coupling and carbon budgets in the Adriatic and Northern Ionian Sea

    NASA Astrophysics Data System (ADS)

    Giordani, P.; Helder, W.; Koning, E.; Miserocchi, S.; Danovaro, R.; Malaguti, A.

    2002-06-01

    The Adriatic sea is generally viewed as a long bay in the Central Mediterranean, stretching SE to NW for 800 km, from the Strait of Otranto to the Gulf of Venice, with an extremely long, geometrically complex coastline, creating a high diversity of hydrodynamic and sedimentary environments. The seafloor slopes down from the North shallow shelf (mean depth 35 m) through the middle Adriatic depression (250 m depth in the Pomo Pit) to the bathyal reached in the Southern Adriatic pit (1260 m). Typical physiographic and climatic features strongly influence biological productivity. The productivity of the Northern Adriatic is among the highest in the Mediterranean, while it becomes lower in the offshore waters of the Central and Southern subbasins, defining clear oligotrophic and benthic-pelagic coupling gradients from the Northern to the Southern edge of the basin. Assessing the benthic response to particulate fluxes of organic matter from the photic layer was a target of the EU-MATER Project. The applied methodological strategy involved measurements of primary production by 14C in situ incubation technique, of particulate fluxes through the water column by moored sediment traps, of sediment community oxygen consumption (SCOC) by in situ and on-deck incubations, and of carbon burial fluxes at three sites in the Southern Adriatic (A1), the Otranto Strait (O2) and the Ionian sea (I1), along the main pathway of outflowing water masses. In this paper, yearly budget calculations of carbon are presented for stations, selected as being representative of wider areas in the three subbasins, to give a picture of the Adriatic basin as a whole. Data from the Northern basin, obtained by the same methodology, come from previous research programmes carried out in the framework of EU Marine projects (STEP/Adria and MTP 1/Euromarge AS). The carbon fraction reaching the seafloor was quantified as the sum of SCOC and burial fluxes and was compared to 14C primary production measurements in

  20. Water mass characteristics in the deep layers of the western Ionian Basin observed during May 2003

    NASA Astrophysics Data System (ADS)

    Hainbucher, D.; Rubino, A.; Klein, B.

    2006-03-01

    CTD measurements carried out in the southern Adriatic Sea and in the western Ionian basin (Eurafrican Mediterranean Sea) during May 2003 by the German research vessel Poseidon (Poseidon cruise 298) and numerical simulations are used to elucidate aspects of the abyssal circulation of this oceanic region. The observations reveal that dense waters of Adriatic origin were strongly diluted along their way on the Italian continental slope, whilst their characteristics remained better preserved in a region located further east. Numerical simulations carried out by means of a nonlinear, reduced-gravity plume model confirm the observations and contribute to explain their cause: The very steep topographic slope along the Italian shelf in the region of the Gulf of Taranto induces strong entrainment of intermediate waters in the bottom layers. Instead, the bottom waters of Adriatic origin which, along their path further east, encounter gentler topographic variations, are weakly diluted by turbulent mixing and, therefore, better preserve their original characteristics. The remarkable differences in the simulated turbulent mixing along these two different paths are accentuated by the presence of a noticeable zonal gradient of potential density existing in the near-bottom layers of the northern Ionian basin.

  1. Meteorological and oceanographic conditions in the northern Adriatic Sea during the period June 1999-July 2002: influence on the mucilage phenomenon.

    PubMed

    Russo, Aniello; Maccaferri, Simona; Djakovac, Tamara; Precali, Robert; Degobbis, Danilo; Deserti, Marco; Paschini, Elio; Lyons, Daniel M

    2005-12-15

    Mucilage events (formation of very large organic aggregates and gelatinous surface layers) have been documented several times during the past two centuries in the northern Adriatic Sea (NA), while their frequency has significantly increased since 1988. In this work, meteorological and oceanographic conditions in the NA during the period June 1999-July 2002 are described and their relation to the outbreak and fate of the mucilage phenomenon was investigated. Salinity and temperature data were collected during approximately monthly cruises along three transects in the NA. Relevant meteorological situations (air temperature, rainfall, wind) were selected from large-scale ECMWF analyses and from the Local Analysis and Prediction System (LAPS; Emilia Romagna Meteorological Service), while sea conditions (waves) were analysed by means of the Wave Adriatic Model (WAM). Data for air temperature, rainfall, and wind from several meteorological stations in the region were used. Average seasonal cycles of sea temperature and salinity simulated with statistical models, based on historical data collected in the NA since 1972, were used to determine thermal and haline anomalies. The monthly anomaly variability of maximum and minimum air temperatures, rainfall amount and number of rainy days did not appear to be relevant for the mucilage phenomenon outbreak. In contrast, both vertical and horizontal thermohaline gradients in the region were more developed during late spring and summer of 2000 and particularly of 2002, when the mucilage events were of greatest extent in space and time, compared to 2001 (short-lived event) and 1999 (no event). These more pronounced gradients were due to a combination of several unusual conditions: sharp heating of the sea surface in May-June, domination of eastwards transport of freshened waters formed in the Po Delta area, and intrusion of very high salinity intermediate waters originating in the eastern Mediterranean. Moreover, in winter of both

  2. Dense water formation in the north-western Mediterranean area during HyMeX-SOP2 in 1/36° ocean simulations: Sensitivity to initial conditions

    NASA Astrophysics Data System (ADS)

    Léger, Fabien; Lebeaupin Brossier, Cindy; Giordani, Hervé; Arsouze, Thomas; Beuvier, Jonathan; Bouin, Marie-Noëlle; Bresson, Émilie; Ducrocq, Véronique; Fourrié, Nadia; Nuret, Mathieu

    2016-08-01

    The north-western Mediterranean Sea is a key location where intense air-sea exchanges occur in autumn and winter. The succession of strong mistral and tramontane situations, leading to significant evaporation and ocean heat loss, is well known as the controlling factor in the dense water formation (DWF) with deep convection episodes. During HyMeX-SOP2 (1 February to 15 March 2013), several platforms sampled the area in order to document DWF and air-sea exchanges. This study investigates the ability of the NEMO-WMED36 ocean model (1/36°-resolution), driven in surface by the hourly air-sea fluxes from the AROME-WMED forecasts (2.5 km resolution), to represent DWF during HyMeX-SOP2 and focuses on the sensitivity to initial conditions. After a short evaluation of the atmospheric forcing, the high-resolution oceanic simulations using three different data sets as initial and boundary conditions are compared to observations collected during the field campaign. It evidences that using regional model outputs may lead to unrealistic thermohaline characteristics for the intermediate and deep waters, which degrade the simulated new dense water formed. Using ocean analyses built from observations, permits to obtain more realistic characteristics of the Western Mediterranean dense water. However, a low stratification favors an overestimation of the convective area and of the DWF rate. The DWF chronology is also impacted. Nevertheless, in every run, SOP2 is characterized by the production of water denser than 29.11 kg m-3 with a peak during the strong mistral event of 23-25 February followed by a period of restratification, before a last event of bottom convection on 13-15 March.

  3. A nonstationary analysis for the Northern Adriatic extreme sea levels

    NASA Astrophysics Data System (ADS)

    Masina, Marinella; Lamberti, Alberto

    2013-09-01

    The historical data from the Trieste, Venice, Porto Corsini, and Rimini tide gauges have been used to investigate the spatial and temporal changes in extreme high water levels in the Northern Adriatic. A detailed analysis of annual mean sea level evolution at the three longest operating stations shows a coherent behavior both on a regional and global scale. A slight increase in magnitude of extreme water elevations, after the removal of the regularized annual mean sea level necessary to eliminate the effect of local subsidence and sea level rise, is found at the Venice and Porto Corsini stations. It seems to be mainly associated with a wind regime change occurred in the 1990s, due to an intensification of Bora wind events after their decrease in frequency and intensity during the second half of the 20th century. The extreme values, adjusted for the annual mean sea level trend, are modeled using a time-dependent GEV distribution. The inclusion of seasonality in the GEV parameters considerably improves the data fitting. The interannual fluctuations of the detrended monthly maxima exhibit a significant correlation with the variability of the large-scale atmospheric circulation represented by the North Atlantic Oscillation and Arctic Oscillation indices. The different coast exposure to the Bora and Sirocco winds and their seasonal character explain the various seasonal patterns of extreme sea levels observed at the tide gauges considered in the present analysis.

  4. Sediment transport processes at the head of Halibut Canyon, Eastern Canada margin: An interplay between internal tides and dense shelf water cascading.

    NASA Astrophysics Data System (ADS)

    Puig, Pere; Greenan, Blair J. W.; Li, Michael Z.; Prescott, Robert H.; Piper, David J. W.

    2013-04-01

    To investigate the processes by which sediment is transported through a submarine canyon incised in a glaciated margin, the bottom boundary layer quadrapod RALPH was deployed at 276-m depth in the West Halibut Canyon (off Newfoundland) during winter 2008-2009. Two main sediment transport processes were identified throughout the deployment. Firstly, periodic increases of near-bottom suspended-sediment concentrations (SSC) were recorded associated with the up-canyon propagation of the semidiurnal internal tidal bore along the canyon axis, carrying fine sediment particles resuspended from deeper canyon regions. The recorded SSC peaks, lasting less than one hour, were observed sporadically and were linked to bottom intensified up-canyon flows concomitant with sharp drops in temperature. Secondly, sediment transport was also observed during events of intensified down-canyon current velocities that occurred during periods of sustained heat loss from surface waters, but were not associated with large storms. High-resolution velocity profiles throughout the water column during these events revealed that the highest current speeds (~1 m s-1) were centered several meters above the sea floor and corresponded to the region of maximum velocities of a gravity flow. Such flows had associated low SSC and cold water temperatures and have been interpreted as dense shelf water cascading events channelized along the canyon axis. Sediment transport during these events was largely restricted to bedload and saltation, producing winnowing of sands and fine sediments around larger gravel particles. Analysis of historical hydrographic data suggests that the origin of such gravity flows is not related to the formation of coastal dense waters advected towards the canyon head. Rather, the dense shelf waters appear to be generated around the outer shelf, where convection during winter is able to reach the sea floor and generate a pool of near-bottom dense water that cascades into the canyon

  5. Trends and interactions of physical and bio-geo-chemical features in the Adriatic Sea as derived from satellite observations.

    PubMed

    Barale, Vittorio; Schiller, Christian; Tacchi, Ruggero; Marechal, Cecile

    2005-12-15

    Time series of satellite data, generated by the AVHRR (1981-1999), CZCS (1979-1985) and SeaWiFS (1998-2002), have been used to assess trends and interactions of physical and bio-geo-chemical features in the Adriatic Sea. The images were processed to estimate Sea Surface Temperature (SST) and Chlorophyll-like Pigment Concentration (CPC). Long-term composites and climatologies were derived, using fixed geographical grids and projections. The AVHRR data show an apparent warming trend, when plotting the sequence of seasonal cycles (monthly mean SST, averaged over the whole basin) against time, due to a steady rise of summer values. Considering 3 regions (north, central and south), split into east and west sections, the northern Adriatic shows high SST fluctuations (possibly associated with the cycle of winter cooling and summer warming, typical of the relatively shallow sub-basin), while the southern Adriatic exhibits a lower variability (possibly influenced by the periodic water incoming from, and outflowing to the Ionian Sea). During summer, an east-west gradient prevails, while during winter only a general north-south gradient can be found. The SeaWiFS-derived CPC values, distributions and trends appear to be consistent with the historical CZCS record. Persistent differences in the quantitative assessment of CPC for coastal waters is due to the use of improved algorithms, less influenced by the presence of dissolved organics and suspended sediments in the water column, for the processing of SeaWiFS data. Apparent incongruities of the space and time patterns in the SeaWiFS record with respect to the reference climatology, obtained by CZCS more than a decade before, occur chiefly when considering the spring bloom in the southern Adriatic and the summer development of the north Adriatic front. The comparison of the long-term times series of satellite data shows that there is a high correlation between patterns in the thermal field and in the colour field. This suggests

  6. A numerical study of the interannual variability of the Adriatic Sea (2000-2002).

    PubMed

    Oddo, Paolo; Pinardi, Nadia; Zavatarelli, Marco

    2005-12-15

    A free-surface, three-dimensional finite-difference numerical model based on the Princeton Ocean Model (POM) has been implemented in order to simulate the interannual variability of the Adriatic Sea circulation. The implementation makes use of an interactive surface momentum and heat flux computation that utilizes the European Centre for Medium-Range Weather Forecasts (ECMWF) 6-h analyses and the model predicted sea surface temperatures. The model is also nested at its open boundary with a coarse-resolution Mediterranean general circulation model, utilizing the same surface forcing functions. The simulation and analysis period spans 3 years (1 Jan 2000 to 31 Dec 2002) coinciding with the "Mucilage in the Adriatic and the Tyrrhenian" (MAT) Project monitoring activities. Model results for the simulated years show a strong interannual variability of the basin averaged proprieties and circulation patterns, linked to the atmospheric forcing variability and the Po river runoff. In particular, the years 2000 and 2002 are characterized by a weak surface cooling (with respect to the climatological value) and well-marked spring and autumn river runoff maxima. Conversely, 2001 is characterized by stronger wind and heat (autumn cooling) forcings but no river runoff autumn peak, even though the total amount of water inflow during winter and spring is sustained. The circulation is characterized by similar patterns in 2000 and 2002 but very different structures in 2001. During the latter, deep water is not formed in the northern Adriatic. A comparison with the observed data shows that the major model deficiencies are connected to the low salinity of the waters, probably connected to the missed inflow of salty Ionian waters of Aegean origin and to the numerical overestimation of the vertical mixing processes.

  7. Modeling the drift of plastics in the Adriatic Basin

    NASA Astrophysics Data System (ADS)

    Liubartseva, Svitlana; Coppini, Giovanni; Lecci, Rita; Creti, Sergio

    2016-04-01

    Recently, plastic pollution at sea has become widely recognized as an acute environmental problem. Distribution of plastics in the marine environment is controlled by (1) locations and time-varying intensity of inputs; (2) the dynamics of the upper mixed layer of the ocean, where the majority of plastics float; and (3) the sinks of plastics. In the present work, we calculate the plastic concentrations at the sea surface and fluxes onto the coastline (2009-2015) that originated from terrestrial and maritime inputs. We construct a Markov chain model based on coupling the MEDSLIK-II model (De Dominicis et al., 2013) with the daily Adriatic Forecasting System (AFS) ocean currents simulations (1/45° horizontal resolution) (Guarneri et al., 2010) and ECMWF surface wind analyses (0.25° horizontal and 6-h temporal resolutions). We assume that the coastline is the main sink of plastics in the Adriatic Sea (Liubartseva et al., 2015). Our calculations have shown that the mean particle half-life in the basin approximately equals 43.7 days, which allows us to define the Adriatic Sea as a highly dissipative system with respect to floating plastics. On long-term time-mean scales, the most polluted sea surface area (more than 10 g/km2 floating plastics) is represented by an elongated band shifted to the Italian coastline and narrowed from northwest to southeast. That corresponds to the spatial distributions of plastic inputs, and indicates a tight connection with patterns of the general Adriatic circulation, including the Western Adriatic Coastal Current and the South Adriatic gyre. On seasonal time-mean scales, we indicate the winter plastics' expansion into the basin's interior, spring trapping in the northern Adriatic, summer cleansing the middle and southern Adriatic and autumn spreading into the southeastern Adriatic. Distinctive coastal "hot spot" is found on the Po Delta coastline that receives a plastic flux of 70 kg/(kmṡday). Complex source-receptor relationships

  8. Self-Organizing Maps method in recent Adriatic Sea environmental studies: applications and perspectives

    NASA Astrophysics Data System (ADS)

    Mihanovic, H.; Vilibic, I.

    2014-12-01

    Herein we present three recent oceanographic studies performed in the Adriatic Sea (the northernmost arm of the Mediterranean Sea), where Self-Organizing Maps (SOM) method, an unsupervised neural network method capable of recognizing patterns in various types of datasets, was applied to environmental data. The first study applied the SOM method to a long (50 years) series of thermohaline, dissolved oxygen and nutrient data measured over a deep (1200 m) Southern Adriatic Pit, in order to extract characteristic deep water mass patterns and their temporal variability. Low-dimensional SOM solutions revealed that the patterns were not sensitive to nutrients but were determined mostly by temperature, salinity and DO content; therefore, the water masses in the region can be traced by using no nutrient data. The second study encompassed the classification of surface current patterns measured by HF radars over the northernmost part of the Adriatic, by applying the SOM method to the HF radar data and operational mesoscale meteorological model surface wind fields. The major output from this study was a high correlation found between characteristic ocean current distribution patterns with and without wind data introduced to the SOM, implying the dominant wind driven dynamics over a local scale. That nominates the SOM method as a basis for generating very fast real-time forecast models over limited domains, based on the existing atmospheric forecasts and basin-oriented ocean experiments. The last study classified the sea ambient noise distributions in a habitat area of bottlenose dolphin, connecting it to the man-made noise generated by different types of vessels. Altogether, the usefulness of the SOM method has been recognized in different aspects of basin-scale ocean environmental studies, and may be a useful tool in future investigations of understanding of the multi-disciplinary dynamics over a basin, including the creation of operational environmental forecasting systems.

  9. Hydrographic characteristics of water masses and circulation in the Northern Ionian Sea

    NASA Astrophysics Data System (ADS)

    Budillon, Giorgio; Bue, Nadia Lo; Siena, Giuseppe; Spezie, Giancarlo

    2010-03-01

    The hydrography of intermediate and deep-water masses in the Northern Ionian Sea (Apulian Plateau) was studied through four quasi-synoptic multidisciplinary surveys carried out in 2004-2006 as an ancillary oceanographic activity in the frame of the APLABES project. This area plays a crucial role for the entire Mediterranean Basin, being influenced by the water outflow of Adriatic origin, which, under severe winter conditions, is a primary source of dense water for the Eastern Mediterranean. At the end of the 1980s such outflow showed a different behavior, and only in the recent years has a gradual re-establishing of the former condition been detected. As such, the Adriatic Sea has regained its role as a main source of the East Mediterranean Deep Water, which was temporarily inhibited during the well-known Eastern Mediterranean Transient which progressively modified the intermediate and deep layers of the Mediterranean Sea. The general structure of water masses was similar through the investigated period, but interesting differences within the bottom layer have been detected. The interaction of the different water types present in the basin is reviewed by means of property-property plots, vertical sections, isopycnal analyses and using an Optimum Multiparameter Analysis (OMP), which is an objective method to measure the mixing of water masses. Due to the lack of any direct information about the dynamics of the water column in the area of the Apulian Plateau during the whole analyzed period, the classical method to infer the baroclinic velocity from the mass field has been applied to hydrographic data. The well-known indeterminacy of this method due to the barotropic component of the velocity field has been resolved using a short time series of current velocities acquired synoptically by a mooring located in the northern part of the studied area. The wavelet transform was adopted for localizing and quantifying the variability of currents simultaneously in both

  10. Carbonate chemistry in the Mertz Polynya (East Antarctica): Biological and physical modification of dense water outflows and the export of anthropogenic CO2

    NASA Astrophysics Data System (ADS)

    Shadwick, E. H.; Tilbrook, B.; Williams, G. D.

    2014-01-01

    Dense shelf water (DSW) is formed in East Antarctica from enhanced sea-ice production driven by air-sea interaction in coastal polynyas. Cross-shelf export and downslope mixing of this DSW produces Antarctic Bottom Water, contributing to the lower limb of the global overturning circulation. We present biogeochemical observations from the Mertz Polynya region in summer 2007/2008, with additional observations from spring 2001 and winter 1996. The seasonal changes in mixed-layer carbonate chemistry are driven by a combination of air-sea CO2 exchange, biological activity and the formation and melt of sea-ice. The air-sea fluxes in 2008 were ˜15 mmol C m-2 d-1, and net community production, estimated from the summertime surface dissolved inorganic carbon (DIC) deficit, ranged from 0.9 to 1.2 mol C m-2 yr-1. We show that biological modification of carbonate chemistry over the shelf in summer preconditions the DSW outflows from the Adélie Depression. This process appears to supply both organic material, and water depleted in CO2, and with enhanced carbonate saturation state (relative to inflowing water), to coral communities on the slope. We combined model-based transports of exported DSW with the natural and anthropogenic (Cant) carbon concentrations and estimate that the annual outflows of DIC and Cant from the Mertz Polynya range from 320 to 560 Tg C yr-1, and from 3 to 6 Tg Cant yr-1, respectively. The formation and export of dense water from this region, and by extension all similar polynyas around Antarctica, is an effective mechanism for the transfer of anthropogenic carbon into the deep ocean.

  11. {sup 210}Pb dating of sediments from the central and northern Adriatic Sea: deposition and preservation of sedimentary organic carbon

    SciTech Connect

    Hamilton, T. F., LLNL

    1998-04-01

    Lead-210 ({sup 21O}Pb) and organic C depth distribution profiles in sediments from the northern and central Adriatic Sea were measured as part of the EEC funded project on Eutrophic Limits of the Northern Adriatic (ELNA). {sup 210}Pb derived mass-accumulation rates decrease southward from between 0.15 and 0.2 g cm{sup -2}y{sup -1} close to the Po River outflow (> 24 m, water depth) to less than 0.04 g cm{sup -2}y{sup -1} in the Jabuka Pit (246 m, water depth) in the central Adriatic Sea. The mass- accumulation rates obtained in the Jabuka Pit correspond to mean sedimentation rates of about 0.03 cm y{sup -1} (ref. porosity = 0.5) and fall between 5 to 20 times lower than rates found for north Adriatic shelf cores. Estimated sedimentation rates are considered as upper limits because of the possible effects of bioturbation and physical disturbance on the {sup 21O}Pb sedimentary record but are consistent with data from previous work. Rates of sediment accumulation and carbon burial appear to be strongly influenced by the transport of fluvial materials from land and transport of fine-grained particles. First-order estimates of organic C burial rates into surface sediment ranged from 1 to 0.028 mMol cm{sup -2}y{sup -1} between the Po delta and the Jabuka Pit regions, respectively. We estimate that a maximum of 50% of organic C preserved in surface sediment may be derived from biological production in the overlying water column.

  12. Rogoznica Lake (Croatia), a unique anoxic seawater system on the Adriatic coast under the anthropogenic pressures

    NASA Astrophysics Data System (ADS)

    Ciglenečki, Irena; Bura-Nakić, Elvira; Marguš, Marija; Čanković, Milan; Carić, Marina; Viličić, Damir; Ljubešić, Zrinka; Kršinić, Frano; Batistić, Mirna; Janeković, Ivica; Plavčić, Filip

    2014-05-01

    Rogoznica Lake is a typical example of euxinic saline lake, situated on the eastern Adriatic coast (43o32'N 15o58'E). It is a karstic depression filled with seawater, with an area of 10276 m2 and a maximum depth of 15m The lake has circular shape and is surrounded with sheer, karstic cliffs (4-23 m high), which completely protect the lake from the influence of the wind. During the year the lake is thermally, densely and chemically stratified into oxic and anoxic layers. The surface water is well oxygenated, while hypoxia/anoxia occurs in the bottom layer. The mixolimnion varies seasonally and it is greatly influenced by meteorological conditions (temperature, wind, rainfall) which also influence the water layer mixing. Vertical mixing usually occurs during autumn/winter when cold, oxygen-rich water from the surface sinks downwards. Depending on the intensity of the mixing process anoxic conditions in the entire water column could appear. At the boundary oxia-anoxia usually a pinky colored chemocline layer, cca 50 cm thick develops. Anoxic deep water is characterized by high concentrations of reduced sulfur compounds (RSS up to 1mM, mainly in the form of sulfide), and nutrients (NH4+, up to 150 μM; PO43-, up to 22 μM; SiO44-, up to 400 μM) as well as dissolved organic carbon (DOC up to 6 mg l-1) indicating the pronounced remineralization of allochthonous organic matter produced in the surface water The eutrophication of the lake is strongly influenced by nutrient recycling under anaerobic conditions. Due to the extreme ecological conditions which prevail in this lake, phyto- and zooplankton populations are represented by a relatively small number of species, some of them, however, in the populations denser than those in the surrounding sea. After the period of total anoxia appearance, the number of species and their abundance are significantly reduced in comparison with the pre-anoxia values. Diatoms were found to be the dominant microphytoplankton group while

  13. Bio-irrigation impacts on benthic-pelagic coupling in the Northern Adriatic

    NASA Astrophysics Data System (ADS)

    Capet, Arthur; Solidoro, Cosimo; De Vittor, Cinzia; Cibic, Tamara; Del Negro, Paola

    2016-04-01

    In the process of setting up a 3D benthic-pelagic coupled model for the northern Adriatic Sea, the 1D diagenetic OMEXDIA model was used to analyze pore-water profiles and in-situ flux data through model calibration. We tested two approach to represent bioirrigation in the model: the enhanced-biodiffusive formalism (initially used in OMEXDIA) and the non-local exchange formalism. Solutes profiles depicted shapes that could not be rendered by the biodiffusive formalism. Furthermore, calibration procedures stressed that only the non-local exchange formalism allows to render simultaneously the pore water solute profiles and the fluxes measured at the sediment water interface when carbon, oxygen, nitrogen and phosphate dynamics are considered jointly. While the enhanced-biodiffusive formalism is convenient in empirical studies comparing diffusive and total benthic fluxes for a single variable (derived from solutes profiles and incubation chambers respectively), it is not suited for multivariate modelling purposes. We evidence that the modeled impact of bioirrigation on benthic-pelagic coupling strongly differ following the adopted formalism, in particular in terms of the N:P ratio of remineralized fluxes. Calibrated parameters obtained for various stations are used to assess how bioirrigation impacts on benthic-pelagic coupling in the northern Adriatic.

  14. A high resolution Adriatic-Ionian Sea circulation model for operational forecasting

    NASA Astrophysics Data System (ADS)

    Ciliberti, Stefania Angela; Pinardi, Nadia; Coppini, Giovanni; Oddo, Paolo; Vukicevic, Tomislava; Lecci, Rita; Verri, Giorgia; Kumkar, Yogesh; Creti', Sergio

    2015-04-01

    A new numerical regional ocean model for the Italian Seas, with focus on the Adriatic-Ionian basin, has been implemented within the framework of Technologies for Situational Sea Awareness (TESSA) Project. The Adriatic-Ionian regional model (AIREG) represents the core of the new Adriatic-Ionian Forecasting System (AIFS), maintained operational by CMCC since November 2014. The spatial domain covers the Adriatic and the Ionian Seas, extending eastward until the Peloponnesus until the Libyan coasts; it includes also the Tyrrhenian Sea and extends westward, including the Ligurian Sea, the Sardinia Sea and part of the Algerian basin. The model is based on the NEMO-OPA (Nucleus for European Modeling of the Ocean - Ocean PArallelise), version 3.4 (Madec et al. 2008). NEMO has been implemented for AIREG at 1/45° resolution model in horizontal using 121 vertical levels with partial steps. It solves the primitive equations using the time-splitting technique for solving explicitly the external gravity waves. The model is forced by momentum, water and heat fluxes interactively computed by bulk formulae using the 6h-0.25° horizontal-resolution operational analysis and forecast fields from the European Centre for Medium-Range Weather Forecast (ECMWF) (Tonani et al. 2008, Oddo et al. 2009). The atmospheric pressure effect is included as surface forcing for the model hydrodynamics. The evaporation is derived from the latent heat flux, while the precipitation is provided by the Climate Prediction Centre Merged Analysis of Precipitation (CMAP) data. Concerning the runoff contribution, the model considers the estimate of the inflow discharge of 75 rivers that flow into the Adriatic-Ionian basin, collected by using monthly means datasets. Because of its importance as freshwater input in the Adriatic basin, the Po River contribution is provided using daily average observations from ARPA Emilia Romagna observational network. AIREG is one-way nested into the Mediterranean Forecasting

  15. Diversity of the genus Terebellides (Polychaeta: Trichobranchidae) in the Adriatic Sea with the description of a new species.

    PubMed

    Parapar, Julio; Mikac, Barbara; Fiege, Dieter

    2013-01-01

    Based on specimens collected during the sampling campaigns in the Northern Adriatic from 2003-2010, the diversity of genus Terebellides (Polychaeta; Trichobranchidae) was studied and three species are reported for the Northern Adriatic Sea: Terebellides gracilis Malm, 1874, Terebellides mediterranea spec. nov., and Terebellides stroemii Sars, 1835. Terebellides stroemii was the only species previously reported from the area. Terebellides gracilis is reported for the first time for the Mediterranean Sea and its geographical distribution is extended south. Terebellides mediterranea spec. nov., is characterised by the presence of long notopodia and notochaetae in the first thoracic chaetiger. These three species are compared to other Terebellides species described or reported from North Atlantic waters, and a key to Terebellides species of the North East Atlantic and Mediterranean is provided.

  16. Phylogeography of isolated freshwater three-spined stickleback Gasterosteus aculeatus populations in the Adriatic Sea basin.

    PubMed

    DeFaveri, J; Zanella, L N; Zanella, D; Mrakovčić, M; Merilä, J

    2012-01-01

    Analyses of mitochondrial (mt) DNA and microsatellite variation were carried out to examine the relationships between 10 freshwater populations of three-spined sticklebacks Gasterosteus aculeatus along the eastern coast of the Adriatic Sea. Partial sequences of the mtDNA control region and cytochrome b gene, in addition to 15 microsatellite loci, were used to analyse populations from four isolated river catchments. Results uncovered an Adriatic lineage that was clearly divergent from the European lineage, and confirmed that the most divergent and ancient populations are located within the Adriatic lineage as compared with other European populations. Two northern Adriatic populations formed independent clades within the European mitochondrial lineage, suggesting different colonization histories of the different Adriatic populations. Nuclear marker analyses also indicated deep divergence between Adriatic and European populations, albeit with some discordance between the mtDNA phylogeny of the northern Adriatic populations, further highlighting the strong differentiation among the Adriatic populations. The southern populations within the Adriatic lineage were further organized into distinct clades corresponding to respective river catchments and sub-clades corresponding to river tributaries, reflecting a high degree of population structuring within a small geographic region, concurrent with suggestions of existence of several microrefugia within the Balkan Peninsula. The highly divergent clades and haplotypes unique to the southern Adriatic populations further suggest, in accordance with an earlier, more limited survey, that southern Adriatic populations represent an important reservoir for ancient genetic diversity of G. aculeatus.

  17. Late Quaternary transgressive large dunes on the sediment-starved Adriatic shelf

    USGS Publications Warehouse

    Correggiari, A.; Field, M.E.; Trincardi, F.

    1996-01-01

    The Adriatic epicontinental basin is a low-gradient shelf where the late-Quaternary transgressive systems tract (TST) is composed of thin parasequences of backbarrier, shoreface and offshore deposits. The facies and internal architecture of the late-Quaternary TST in the Adriatic epicontinental basin changed consistently from early transgression to late transgression reflecting: (1) fluctuations in the balance between sediment supply and accommodation increase, and (2) a progressive intensification of the oceanographic regime, driven by the transgressive widening of the basin to as much as seven times its lowstand extent. One of the consequences of this trend is that high-energy marine bedforms such as sand ridges and sand waves characterize only areas that were flooded close to the end of the late-Quaternary sea-level rise, when the wind fetch was maximum and bigger waves and stronger storm currents could form. We studied the morphology, sediment composition and sequence-stratigraphical setting of a field of asymmetric bedforms (typically 3 m high and 600 m in wavelength) in 20-24 m water depth offshore the Venice Lagoon in the sediment-starved North Adriatic shelf. The sand that forms these large dunes derived from a drowned transgressive coastal deposit reworked by marine processes. Early cementation took place over most of the dune crests limiting their activity and preventing their destruction. Both the formation and deactivation of this field of sand dunes occurred over a short time interval close to the turn-around point that separates the late-Quaternary sea-level rise and the following highstand and reflect rapid changes in the oceanographic regime of the basin.

  18. February 2003 marine atmospheric conditions and the bora over the northern Adriatic

    USGS Publications Warehouse

    Dorman, C.E.; Carniel, S.; Cavaleri, L.; Sclavo, M.; Chiggiato, J.; Doyle, J.; Haack, T.; Pullen, J.; Grbec, B.; Vilibic, I.; Janekovic, I.; Lee, C.; Malacic, V.; Orlic, M.; Paschini, E.; Russo, A.; Signell, R.P.

    2007-01-01

    A winter oceanographic field experiment provided an opportunity to examine the atmospheric marine conditions over the northern Adriatic. Mean February winds are from a northeasterly direction over most of the Adriatic and a more northerly direction along the western coast. Wind speeds are fastest in jets over the NE coast during bora events and weakest in the mid-northwestern Adriatic. Diurnal air temperature cycles are smallest on the NE coast and largest in the midwestern Adriatic. The maximum sea-air difference is +10??C on the eastern coast and near zero on the midwestern Adriatic. Boras are northeasterly (from) wind events that sweep off Croatia and Slovenia, bringing slightly colder and drier air over the northern Adriatic. The main bora season is December to March. Winter 2002-2003 was normal for bora events. Synoptic-scale temporal variations are correlated over the northern Adriatic. Fastest Bora winds and highest wind stress over the northern Adriatic is concentrated in four topographically controlled jets. The strongest is the Senj Jet, while the Trieste Jet extends across the entire northern Adriatic. Between each two jets is a weak wind zone. The greatest mean net heat loss is in bora jets in the NE Adriatic, where it was -438 W m-2 and is weakest in the midwestern northern Adriatic, where it was near zero. Wind stress is concentrated over the NE half of Adriatic in four bora jets, while wind stress is weak in the NW Adriatic. There is significant variation in wind stress mean and standard deviation structure over the northern Adriatic with each bora event. Copyright 2006 by the American Geophysical Union.

  19. Zooplankton community and hydrographical properties of the Neretva Channel (eastern Adriatic Sea)

    NASA Astrophysics Data System (ADS)

    Vidjak, Olja; Bojanić, Natalia; Kušpilić, Grozdan; Ninčević Gladan, Živana; Tičina, Vjekoslav

    2007-12-01

    Temporal and spatial variability of micro and mesozooplankton was studied in 1998 and 1999 at four stations in the Neretva Channel area influenced by the Neretva river and the open waters of the south Adriatic Sea. The area is orthophosphate limited, but an excessive accumulation of land derived nitrogen is prevented by phytoplankton uptake and the general circulation pattern. Microzooplankton was dominated by ciliates, with average abundances comparable to other Adriatic channel areas (122 543 ind. l-1). Non-loricate ciliates (NLC) generally peaked in the warmer periods, but a winter increase was evident towards the inner part of the channel. Tintinnid abundances generally increased in autumn. A significant relationship with temperature was not recorded for either protozoan group. An inverse relationship between NLC and salinity might be indirectly caused by their preference for the food abundant surface layer. Mesozooplankton was dominated by copepods, with distinct summer maxima throughout the area and pronounced winter maxima of >10,000 ind. m-3 at the inner stations. The community was predominantly neritic but the open sea waters were important in structuring the mesozooplankton assemblage at all stations during the autumn winter period. Although temperature regulated the seasonal dynamics of most metazoans and the species succession in the copepod community, small omnivorous copepods ( Oncaea media complex, Oithona nana and Euterpina acutifrons) dominated regardless of the season. A trophic link between copepods and ciliates was evident in winter during low phytoplankton biomass.

  20. Radionuclides in the adriatic sea and related dose-rate assessment for marine biota.

    PubMed

    Petrinec, Branko; Strok, Marko; Franic, Zdenko; Smodis, Borut; Pavicic-Hamer, Dijana

    2013-01-01

    Artificial and natural radionuclides were determined in the Adriatic Sea in the seawater and sediment samples in the period from 2007 to 2011. The sampling areas were coastal waters of Slovenia, Croatia and Albania, together with the deepest part of the Adriatic in South Adriatic Pit and Otranto strait. Sampling locations were chosen to take into account all major geological and geographical features of this part of the Adriatic Sea and possible coastal influences. After initial sample preparation steps, samples were measured by gamma-ray spectrometry. In the seawater ⁴⁰K activity concentrations were in the range from 6063 to 10519 Bq m⁻³, ¹³⁷Cs from 1.6 to 3.8 Bq m⁻³, ²²⁶Ra from 23 to 31 Bq m⁻³, ²²⁸Ra from 1 to 25 Bq m⁻³ and ²³⁸U from 64 to 490 Bq m⁻³. The results of sediment samples showed that ⁴⁰K was in the range from 87 to 593 Bq kg⁻¹, ¹³⁷Cs from 0.8 to 7.3 Bq kg⁻¹, ²²⁶Ra from 18 to 35 Bq kg⁻¹, ²²⁸Ra from 4 to 29 Bq kg⁻¹ and ²³⁸U from 14 to 120 Bq kg⁻¹. In addition, the ERICA Assessment Tool was used for the assessment of dose rates for reference marine organisms using the activity concentrations of the determined radionuclides in seawater. The assessment showed that for the most of the organisms, the dose rates were within the background levels, indicating that the determined values for seawater does not pose a significant risk for the most of marine biota. In the study, the results are critically discussed and compared with other similar studies worldwide. Generally, the activity concentrations of the examined radionuclides did not differ from those reported for the rest of the Mediterranean Sea.

  1. Insights on Continental Collisional Processes from GPS Data: Dynamics of the Peri-Adriatic Belts

    NASA Astrophysics Data System (ADS)

    Metois, Marianne; D'Agostino, Nicola; Avallone, Antonio; Chamot-Rooke, Nicolas; Rabaute, Alain; Duni, Llambro; Kuka, Neki; Koci, Rexhep; Georgiev, Ivan

    2015-04-01

    Recent advances in GPS technology and processing strategies make now spatial geodesy a suitable tool to image intra-continental slowly deforming areas such as collisional mountain belts and to get further insights on their kinematics and dynamics. Here, using the peri-Adriatic belts as a test case, we propose a methodology based on accurate GPS velocities to discriminate whether the current day deformation pattern over a mountain belt is controlled at the first order by gravity through gradients of gravitational potential energy. We calculate a new GPS velocity field covering the peri-Adriatic region and the entire Balkan Peninsula, taking advantage of newly available measurements coming from private networks operating since several years in this area. Based on these velocities, we derive the strain rate tensor and an interpolated velocity field using the method of Haines & Holt (1993). Opposite to the commonly accepted hypothesis considering the Balkans as part of the stable Eurasia, we show that the peninsula experiences significant compression across the Dinarides belt and extension toward the Aegean domain South of 44°N. We image a clockwise rotation of the entire peninsula around North Albania, and propose that the lithosphere under the old Scutari-Peck transform zone is weak and acts as a pivot point for this rotation since early Miocene. The Hellenic slab suction and the release of stress in the northern Hellenides subduction zone may favour the southwestward motion of the inner Balkan lithosphere, flowing between the rigid Apulia and Black sea blocks consequently. Because our velocity field is unusually dense in Slovenia and Austria, we picture the Eastern Alps deformation with great details and show that the Austrian Alps are moving eastward together with the Alpine foreland and Bohemian Promontory relative to stable Eurasia. Based on these new GPS data, we investigate the dynamics of the peri-Adriatic mountain belts, in particular of Albania and Eastern

  2. Biocomplexity in Populations of European Anchovy in the Adriatic Sea

    PubMed Central

    Ruggeri, Paolo; Splendiani, Andrea; Occhipinti, Giulia; Fioravanti, Tatiana; Santojanni, Alberto; Leonori, Iole; De Felice, Andrea; Arneri, Enrico; Procaccini, Gabriele; Catanese, Gaetano; Tičina, Vjekoslav; Bonanno, Angelo; Nisi Cerioni, Paola; Giovannotti, Massimo; Grant, William Stewart; Caputo Barucchi, Vincenzo

    2016-01-01

    The sustained exploitation of marine populations requires an understanding of a species' adaptive seascape so that populations can track environmental changes from short- and long-term climate cycles and from human development. The analysis of the distributions of genetic markers among populations, together with correlates of life-history and environmental variability, can provide insights into the extent of adaptive variation. Here, we examined genetic variability among populations of mature European anchovies (n = 531) in the Adriatic (13 samples) and Tyrrhenian seas (2 samples) with neutral and putative non-neutral microsatellite loci. These genetic markers failed to confirm the occurrence of two anchovy species in the Adriatic Sea, as previously postulated. However, we found fine-scale population structure in the Adriatic, especially in northern areas, that was associated with four of the 13 environmental variables tested. Geographic gradients in sea temperature, salinity and dissolved oxygen appear to drive adaptive differences in spawning time and early larval development among populations. Resolving adaptive seascapes in Adriatic anchovies provides a means to understand mechanisms underpinning local adaptation and a basis for optimizing exploitation strategies for sustainable harvests. PMID:27074008

  3. Biocomplexity in Populations of European Anchovy in the Adriatic Sea.

    PubMed

    Ruggeri, Paolo; Splendiani, Andrea; Occhipinti, Giulia; Fioravanti, Tatiana; Santojanni, Alberto; Leonori, Iole; De Felice, Andrea; Arneri, Enrico; Procaccini, Gabriele; Catanese, Gaetano; Tičina, Vjekoslav; Bonanno, Angelo; Nisi Cerioni, Paola; Giovannotti, Massimo; Grant, William Stewart; Caputo Barucchi, Vincenzo

    2016-01-01

    The sustained exploitation of marine populations requires an understanding of a species' adaptive seascape so that populations can track environmental changes from short- and long-term climate cycles and from human development. The analysis of the distributions of genetic markers among populations, together with correlates of life-history and environmental variability, can provide insights into the extent of adaptive variation. Here, we examined genetic variability among populations of mature European anchovies (n = 531) in the Adriatic (13 samples) and Tyrrhenian seas (2 samples) with neutral and putative non-neutral microsatellite loci. These genetic markers failed to confirm the occurrence of two anchovy species in the Adriatic Sea, as previously postulated. However, we found fine-scale population structure in the Adriatic, especially in northern areas, that was associated with four of the 13 environmental variables tested. Geographic gradients in sea temperature, salinity and dissolved oxygen appear to drive adaptive differences in spawning time and early larval development among populations. Resolving adaptive seascapes in Adriatic anchovies provides a means to understand mechanisms underpinning local adaptation and a basis for optimizing exploitation strategies for sustainable harvests.

  4. Molecular characterisation of Anisakidae larvae from fish in Adriatic Sea.

    PubMed

    Vardić Smrzlić, I; Valić, D; Kapetanović, D; Kurtović, B; Teskeredžić, E

    2012-12-01

    In the present study, anisakids from: tuna (Thunnus thynnus) fattened in the Croatian farm in middle Adriatic Sea, three different feral fish species caught near tuna farm (Trachurus trachurus, Scomber japonicus and Oblada melanura) and fish marketed in Croatia (T. trachurus) were analysed by morphology and molecular methods. Larvae were identified to the species level by PCR restriction fragment length polymorphism and characterised by sequencing of nuclear (internal transcribed spacer) and mitochondrial (cytochrome c oxidase subunit 2) markers. The results revealed diverse Anisakidae community consisting of: Anisakis pegreffi, Anisakis simplex (s.s.), Anisakis typica and Hysterothylacium aduncum. This is the first report of A. typica in Adriatic Sea, and also the first record of this species in T. thynnus as host in Mediterranean Sea. Molecular identification of H. aduncum found in co-infection with Anisakis larvae type I expands our knowledge of the occurrence of these taxa in the Adriatic Sea. Zoonotic Anisakidae worms found in fish from the Adriatic Sea could represent a risk to acquire parasitic infection/allergies in Croatia.

  5. Assessing larval connectivity for marine spatial planning in the Adriatic.

    PubMed

    Bray, L; Kassis, D; Hall-Spencer, J M

    2017-04-01

    There are plans to start building offshore marine renewable energy devices throughout the Mediterranean and the Adriatic has been identified as a key location for wind farm developments. The development of offshore wind farms in the area would provide hard substrata for the settlement of sessile benthos. Since the seafloor of the Adriatic is predominantly sedimentary this may alter the larval connectivity of benthic populations in the region. Here, we simulated the release of larvae from benthic populations along the coasts of the Adriatic Sea using coupled bio-physical models and investigated the effect of pelagic larval duration on dispersal. Our model simulations show that currents typically carry particles from east to west across the Adriatic, whereas particles released along western coasts tend to remain there with the Puglia coast of Italy acting as a sink for larvae from benthic populations. We identify areas of high connectivity, as well as areas that are much more isolated, and discuss how these results can be used to inform marine spatial planning and the licensing of offshore marine renewable energy developments.

  6. Fishing management scenarios to rebuild exploited resources and ecosystems of the Northern-Central Adriatic (Mediterranean Sea)

    NASA Astrophysics Data System (ADS)

    Fouzai, Nadia; Coll, Marta; Palomera, Isabel; Santojanni, Alberto; Arneri, Enrico; Christensen, Villy

    2012-10-01

    We examined various fishing management options to recover exploited marine resources and ecosystems of the Northern-Central Adriatic Sea. Dynamic simulations were based on a spatial ecological model previously calibrated with time series of data. Scenarios regarding spatial management were evaluated with the establishment of two marine protected areas, respectively, in the Pomo pit and the northern region. In addition, three temporal simulations of temporary closures and overall reduction of fishing effort of demersal and pelagic fleets (bottom, mid-water trawls and purse seines) were also considered. Simulations were run for 45 years (1975-2020), including the calibration period (1975-2002), and changes in biomass and catch of marine resources were analyzed. Our results confirm that current fishing management in the Adriatic Sea does not have clear beneficial impacts for the recovery of exploited resources, which will remain depleted in 2020 if "business as usual" continues. Simulations of alternative management suggest that both protected areas could be beneficial for fish population recovery predicting an increase in the biomass of commercial fish and predatory organisms. Simulations of temporary closures and overall reduction of fishing effort also show significant benefits for several commercial resources. We argue that both management measures may be effective tools to recover exploited ecosystems of the Northern-Central Adriatic Sea and halt the decline of marine resources.

  7. Water at a hydrophilic solid surface probed by ab-initio molecular dynamics: inhomogeneous thin layers of dense fluid

    SciTech Connect

    Cicero, G; Grossman, J; Galli, G; Catellani, A

    2005-01-28

    We present a microscopic model of the interface between liquid water and a hydrophilic, solid surface, as obtained from ab-initio molecular dynamics simulations. In particular, we focused on the (100)surface of cubic SiC, a leading candidate semiconductor for bio-compatible devices. Our results show that, in the liquid in contact with the clean substrate, molecular dissociation occurs in a manner unexpectedly similar to that observed in the gas phase. After full hydroxylation takes place, the formation of a thin ({approx}3 {angstrom})interfacial layer is observed, which has higher density than bulk water and forms stable hydrogen bonds with the substrate. The liquid does not uniformly wet the surface, rather molecules preferably bind along directions parallel to the Si dimer rows. Our calculations also predict that one dimensional confinement between two hydrophilic surfaces at about 1.3 nm distance does not affect the structural and electronic properties of the whole water sample.

  8. Seawater quality along the Adriatic coast, Croatia, based on toxicity data.

    PubMed

    Bihari, Nevenka; Micić, Milena; Fafandel, Maja

    2004-04-01

    The potential toxicity of organic extracts from 12 seawater samples from each of 24 sampling sites, collected during 1999-2001 along the Adriatic coast, Croatia, was analyzed with the Microtox toxicity bioassay. The results were consistent with the usefulness of Microtox for the detection of accidental toxic events. To determine the water quality of selected areas, cluster analysis for discrimination between groups with similar toxicity load and water quality index as a base for the ranking of sampling sites was introduced. Based on our experimental data, five classes of the quality index were defined, and so areas were ranked in five categories (excellent, good, fair, poor, and very poor) according to their potential toxic influence. The water quality of selected sites for the potential toxicity of organic extracts could be described as excellent at one sampling site, good at 15 sampling sites, and fair at eight sampling sites. Poor and very poor seawater quality was not detected.

  9. Jabuka island (Central Adriatic Sea) earthquakes of 2003

    NASA Astrophysics Data System (ADS)

    Herak, Davorka; Herak, Marijan; Prelogović, Eduard; Markušić, Snježana; Markulin, Željko

    2005-04-01

    We present analyses of one of the strongest earthquake sequences ever recorded within the Adriatic microplate, which occurred near the Jabuka island in the very centre of the Adriatic Sea. The mainshock (29 March 2003, 17:42, ML=5.5) was preceded by over 150 foreshocks, and followed by many aftershocks, over 4600 of which were recorded on the closest station HVAR (about 90 km to the east). As the epicentre was in the open sea and due to the absence of nearby stations, we were able to confidently locate only 597 events. Hypocentral locations were computed by a grid-search algorithm after seven iterations of refining hypocentres and adjusting station corrections. Epicentres lie in a well-defined area of about 300 km 2, just to the W and NW of the Jabuka island. The vertical cross-sections reveal that hypocentres dip to the NE, closely matching faults from the Jabuka-Andrija fault system, as identified on the available reflection profiles in the area. The fault-plane solution of the main shock based on the first-motion polarity readings agrees well with the CMT solutions and indicates faulting caused by a S-N directed tectonic pressure, on a reverse, dip-slip fault. This is in very good agreement with the seismotectonic framework of the area. These earthquakes are important as they identify the Jabuka-Andrija fault system as an active one, which can significantly influence seismic hazard on the islands in the central Adriatic archipelago and on the Croatian coast between Zadar and Split. Along with several other sequences which occurred in the last two decades, they force us to change our notion of Adria as nearly aseismic, compact and rigid block. In fact, it turns out that recent seismicity of the Central Adriatic Sea is comparable to the seismicity of several well known earthquake-prone areas in the circum-Adriatic region.

  10. Long-term variations of folic acid concentrations in the Northern Adriatic.

    PubMed

    Plavsić, Marta

    2004-08-01

    Folic acid (FA), which belongs to B-group vitamins has recently been recognized as possible nutrient for some phytoplankton species (a diatom Phaeodactylum tricornutum). The beneficial role of FA in human health is widely documented. In some countries food fortification with FA has already become mandatory. FA is also used under commercial name of Dosfolat for the treatment of industrial and domestic wastewaters. This is an exploratory study on seasonal and depth variability of FA concentrations in the Northern Adriatic Sea (station 101-max depth 30 m, under the Po River influence). Seawater samples were analysed in the period from February 1998 to February 2003 based on monthly determinations. Those preliminary findings showed that in the upper layer (10 m) FA concentrations were in the range from 0.1 to 28 nM. In the lower layer (20-30 m) FA concentrations were in the range from 0.1 to 12 nM. It was found that phytoplankton and microorganisms which are responsible for the production of FA in the Northern Adriatic (Station 101) were situated at the depth from 5 to 10 m. The observed water column and seasonal distributions depended on a sensitive balance between the production and the consumption of FA.

  11. Gene flow, population growth and a novel substitution rate estimate in a subtidal rock specialist, the black-faced blenny Tripterygion delaisi (Perciformes, Blennioidei, Tripterygiidae) from the Adriatic Sea.

    PubMed

    Koblmüller, Stephan; Steinwender, Bernd; Weiß, Sara; Sefc, Kristina M

    2015-11-01

    Population histories depend on the interplay between exogeneous and endogeneous factors. In marine species, phylogeographic and demographic patterns are often shaped by sea level fluctuations, water currents and dispersal ability. Using mitochondrial control region sequences (n = 120), we infer phylogeographic structure and historic population size changes of a common littoral fish species, the black-faced blenny Tripterygion delaisi (Perciformes, Blennioidei, Tripterygiidae) from the north-eastern Adriatic Sea. We find that Adriatic T. delaisi are differentiated from conspecific populations in the remaining Mediterranean, but display little phylogeographic structure within the Adriatic basin. The pattern is consistent with passive dispersal of planktonic larvae along cyclonic currents within the Adriatic Sea, but limited active dispersal of adults. Demographic reconstructions are consistent with recent population expansion, probably triggered by rising sea levels after the last glacial maximum (LGM). Placing the onset of population growth between the LGM and the warming of surface waters (18 000-13 000 years BP) and employing a novel expansion dating approach, we inferred a substitution rate of 2.61-3.61% per site per MY. Our study is one of only few existing investigations of the genetic structure of animals within the Adriatic basin and is the first to provide an estimate for mitochondrial control region substitution rates in blennioid fishes.

  12. Dense Suspension Splash

    NASA Astrophysics Data System (ADS)

    Zhang, Wendy; Dodge, Kevin M.; Peters, Ivo R.; Ellowitz, Jake; Klein Schaarsberg, Martin H.; Jaeger, Heinrich M.

    2014-03-01

    Upon impact onto a solid surface at several meters-per-second, a dense suspension plug splashes by ejecting liquid-coated particles. We study the mechanism for splash formation using experiments and a numerical model. In the model, the dense suspension is idealized as a collection of cohesionless, rigid grains with finite surface roughness. The grains also experience lubrication drag as they approach, collide inelastically and rebound away from each other. Simulations using this model reproduce the measured momentum distribution of ejected particles. They also provide direct evidence supporting the conclusion from earlier experiments that inelastic collisions, rather than viscous drag, dominate when the suspension contains macroscopic particles immersed in a low-viscosity solvent such as water. Finally, the simulations reveal two distinct routes for splash formation: a particle can be ejected by a single high momentum-change collision. More surprisingly, a succession of small momentum-change collisions can accumulate to eject a particle outwards. Supported by NSF through its MRSEC program (DMR-0820054) and fluid dynamics program (CBET-1336489).

  13. Relationship between microbial communities and mercury species in the seawater of the Central Adriatic Sea

    NASA Astrophysics Data System (ADS)

    Zivkovic, Igor; Horvat, Milena; Kotnik, Joze; Fajon, Vesna; Solic, Mladen; Kanduc, Tjasa

    2016-04-01

    The structure of the microbial food web and its role in biogeochemical processes in marine ecosystems may vary noticeably and depend on environmental trophic status. Importance of picoplankton makes them an essential component for understanding the food web dynamics in marine systems. These small organisms dominate the photosynthetic biomass and primary production in oligotrophic waters like the Adriatic Sea. One of the hypotheses of research is that the factors that enable scavenging nutrients at low concentrations also promote accumulation of contaminants in the biomass of microorganisms. Biologically mediated reactions can transform mercury species and facilitate their entrance into the marine food web in which it bioaccumulates in the form of methylmercury (MeHg). In order to establish relationship between Hg and microbial species, we performed samplings in the Central Adriatic Sea. Samplings were conducted during oceanographic cruises aboard the research vessel Bios Dva from March 2014 to December 2015. Research was constrained to transect from the island of Vis to the Bay of Kastela. Non-filtered water samples were collected for determination of methylmercury (MeHg), total mercury (THg), dissolved gaseous mercury (DGM), and microbial species in Adriatic coastal and open waters. In the pristine environment of the island of Vis, THg concentrations are the lowest and range from 0.14-1.10 ng/L. Mercury contamination from chlor-alkali industrial waters in the Bay of Kastela is observed through the highest THg concentrations (up to 5.58 ng/L). DGM always shows higher values in more contaminated areas (31.8-351 pg/L) than in the pristine environment (22.1-245 pg/L). MeHg concentrations vary, but the highest values are usually found in the Bay of Kastela (up to 34.3 pg/L). Number of picoeukaryotes is the highest in the Bay of Kastela (0.44×106-31.8×106/L) which has been affected by industrial and civil effluents from the surrounding cities. The lowest number is

  14. Dense topological spaces and dense continuity

    NASA Astrophysics Data System (ADS)

    Aldwoah, Khaled A.

    2013-09-01

    There are several attempts to generalize (or "widen") the concept of topological space. This paper uses equivalence relations to generalize the concept of topological space via the concept of equivalence relations. By the generalization, we can introduce from particular topology on a nonempty set X many new topologies, we call anyone of these new topologies a dense topology. In addition, we formulate some simple properties of dense topologies and study suitable generalizations of the concepts of limit points, closeness and continuity, as well as Jackson, Nörlund and Hahn dense topologies.

  15. Spatial variations of scavenging rates within the central and northern Adriatic Sea: Use of U-Th disequilibria

    SciTech Connect

    Hamilton, T.; Heilmann, J.; Fowler, S.; Miquel, J.C.

    1996-04-01

    Dissolved and particulate concentrations of {sup 234}Th, {sup 210}Pb and {sup 210}Po were measured in surface waters of the central and northern Adriatic Sea. The half-lives and biogeochemistry of {sup 234}Th (t{sub 1/2} = 24.1 days), {sup 210}Po (t{sub 1/2} = 138.4 days) and {sup 210}Pb (t{sub 1/2} = 22.3 years) are ideal for studying particle dynamics in the upper water column. It has been observed that the residence time of dissolved {sup 234}Th with respect to removal on biogenic particles is inversely proportional to primary productivity and may be used to predict export from or new production in the euphotic zone. Model-derived {sup 234}Th fluxes can also be used to help validate sediment trap collections in the upper water column. The aim of the present study was to gain an insight into the intensity and variability of active scavenging and particle removal processes in the central and northern Adriatic Sea. This semi-enclosed sea is strongly influenced by fresh water runoff from rivers carrying large quantities of dissolved nutrients and suspended particles. These inputs of nutrients and suspended particles are expected to give rise to large biological and biogeochemical gradients across the Continental Shelf and offer a range of environments for studying particle scavenging and removal processes. The authors have examined the relationships between {sup 234}Th scavenging rates and residence times of dissolved and particulate phases as a function of other physical and biological parameters (primary productivity, POC, chlorophyll, C/N and total suspended matter). Particular reference is made to the two contrasting environments of the Adriatic--a eutrophic zone near the Po River outflow and in the largely oligotrophic waters of the Jabuka Pit.

  16. A P-Vector Approach to Absolute Geostrophic Currents in the Adriatic Sea

    DTIC Science & Technology

    1998-03-01

    the Otranto Gap (OGAP) project in 1994 and 1995 to assess the oceanography and bottom geology of the Southern Adriatic. As part of this project, the...OGEX1 cruise was conducted between 19 and 24 May 1995 with focus in the Otranto Strait, through which the Adriatic is connected to the rest of the...cyclonic circulation in the Southern Adriatic north of 41°N. In contrast, the results in the Otranto Strait area need to be interpreted with caution

  17. Toxin levels and profiles in microalgae from the north-Western Adriatic Sea--15 years of studies on cultured species.

    PubMed

    Pistocchi, Rossella; Guerrini, Franca; Pezzolesi, Laura; Riccardi, Manuela; Vanucci, Silvana; Ciminiello, Patrizia; Dell'Aversano, Carmela; Forino, Martino; Fattorusso, Ernesto; Tartaglione, Luciana; Milandri, Anna; Pompei, Marinella; Cangini, Monica; Pigozzi, Silvia; Riccardi, Elena

    2012-01-01

    The Northern Adriatic Sea is the area of the Mediterranean Sea where eutrophication and episodes related to harmful algae have occurred most frequently since the 1970s. In this area, which is highly exploited for mollusk farming, the first occurrence of human intoxication due to shellfish consumption occurred in 1989, nearly 10 years later than other countries in Europe and worldwide that had faced similar problems. Until 1997, Adriatic mollusks had been found to be contaminated mostly by diarrhetic shellfish poisoning toxins (i.e., okadaic acid and dinophysistoxins) that, along with paralytic shellfish poisoning toxins (i.e., saxitoxins), constitute the most common marine biotoxins. Only once, in 1994, a toxic outbreak was related to the occurrence of paralytic shellfish poisoning toxins in the Adriatic coastal waters. Moreover, in the past 15 years, the Adriatic Sea has been characterized by the presence of toxic or potentially toxic algae, not highly widespread outside Europe, such as species producing yessotoxins (i.e., Protoceratium reticulatum, Gonyaulax spinifera and Lingulodinium polyedrum), recurrent blooms of the potentially ichthyotoxic species Fibrocapsa japonica and, recently, by blooms of palytoxin-like producing species of the Ostreopsis genus. This review is aimed at integrating monitoring data on toxin spectra and levels in mussels farmed along the coast of the Emilia-Romagna region with laboratory studies performed on the species involved in the production of those toxins; toxicity studies on toxic or potentially toxic species that have recently appeared in this area are also reviewed. Overall, reviewed data are related to: (i) the yessotoxins producing species P. reticulatum, G. spinifera and L. polyedrum, highlighting genetic and toxic characteristics; (ii) Adriatic strains of Alexandrium minutum, Alexandrium ostenfeldii and Prorocentrum lima whose toxic profiles are compared with those of strains of different geographic origins; (iii) F

  18. Development of a geotechnical and pile driving database, Adriatic Sea

    SciTech Connect

    Carpaneto, R.; Paoletti, L.; Guaita, P.; Pratico, A.

    1996-12-31

    The paper presents a geotechnical and pile driving data base relevant to offshore installations in the Adriatic Sea. The paper discusses sources of information, structure, content, and engineering applications of the data base. Data available from Agip`s platform installations in the Adriatic was reviewed, and 20 representative platforms were chosen. Two relational data bases were created, for geotechnical and installation data respectively. The data bases provide a comprehensive and organized source of information about past experience in the area. Such experience is now quickly available for geotechnical engineering activities. As a main application of the data bases, information was processed to make data sets for training Artificial Neural Networks (ANN) to predict pile driveability. It is envisioned that the data bases will also be used in ongoing installation program design.

  19. Using an artificial brain to interpret Adriatic surface currents

    NASA Astrophysics Data System (ADS)

    Schultz, Colin

    2011-11-01

    Lying between the Italian peninsula and the northwestern Balkan nations, and separated from the Mediterranean Sea by the Strait of Otranto, the Adriatic Sea is largely cut off from global-scale ocean circulation patterns. As a whole, the Adriatic has a permanent counterclockwise circulation, but in the shallow northern reaches, surface currents vary dramatically over short spans of time, with potentially dangerous consequences for maritime activity. To understand the primary drivers of the fluctuating surface currents, Mihanović et al. perform self-organizing map (SOM) analysis—an emergent computational technique in oceanographic research—on data provided by three high-frequency radar stations operating in the region. As a neural network technique, SOM analysis uses complex mathematical algorithms to train computers to pull patterns from jumbles of data, reducing complex multidimensional observations into simple visual maps. The approach is meant to emulate the learning abilities of biological brains.

  20. Sea surface microplastics in Slovenian part of the Northern Adriatic.

    PubMed

    Gajšt, Tamara; Bizjak, Tine; Palatinus, Andreja; Liubartseva, Svitlana; Kržan, Andrej

    2016-12-15

    Plastics are the most common material of marine litter and have become a global pollution concern. They are persistent in the environment where they gradually degrade into increasingly smaller particles-microplastics (MP). Our study presents results of sea-surface monitoring for MP in the Slovenian part of the Trieste Bay in the Northern Adriatic Sea. In 17 trawls conducted over a 20-month period we found a high average concentration of 406×10(3)MPparticles/km(2). Over 80% of the particles were identified as polyethylene. The significant variability of MP concentrations obtained on different sampling dates is explained by use of surface current maps and a recently developed Markov chain marine litter distribution model for the Adriatic Sea.

  1. Water budget closure based on GRACE measurements and reconstructed evapotranspiration using GLDAS and water use data for two large densely-populated mid-latitude basins

    NASA Astrophysics Data System (ADS)

    Lv, Meixia; Ma, Zhuguo; Yuan, Xing; Lv, Meizhao; Li, Mingxing; Zheng, Ziyan

    2017-04-01

    The GRACE-derived terrestrial water storage change (TWSC) provides an unprecedented opportunity to close the terrestrial water budget. However, it remains challenging to achieve the balance without the consideration of human water use (e.g., irrigation and inter-basin water diversion) for the estimation of other water budget terms such as the evapotranspiration. In this study, the terrestrial water budget closure is tested over the Yellow River Basin (YRB) and Changjiang River Basin (CJB, also called Yangtze River Basin) of China. First, the evapotranspiration is reconstructed using the GLDAS-1 land surface models, the high quality observation-based precipitation, naturalized streamflow, and the irrigation water (hereafter, ETrecon). The ETrecon, evaluated using the mean annual water-balance equation, is of good quality with the absolute relative errors less than 1.9%. The total basin discharge (Rtotal) is calculated as the residual of the water budget among the observation-based precipitation, ETrecon, and the GRACE-TWSC. The difference between Rtotal and the observed total basin discharge is used to evaluate the budget closure, with the consideration of inter-basin water diversion. After the ET reconstruction, the mean absolute imbalance value reduced from 3.31 cm/year to 1.69 cm/year and from 15.40 cm/year to 1.96 cm/year over the YRB and CJB, respectively. The estimation-to-observation ratios of total basin discharge improved from 180.8% to 86.8% over the YRB, and from 67.0% to 101.1% over the CJB. The yearly timescale is the finest temporal scale for the analysis in this study due to the data limitation of naturalized streamflow, irrigation water, and water diversion. The proposed ET reconstruction method is applicable to other human-managed river basins to provide an alternative estimation.

  2. Northern Adriatic Response to a Wintertime Bora Wind Event

    DTIC Science & Technology

    2007-11-02

    REPORT TYPE 3. DATES COVERED (From - To) 19-04-2005 1Journal Article, (refereed) 4. TITLE AND SUBTITLE 5a. CONTRACT NUMBER Northern Adriatic Response...Vilicic It is intended to offer this paper to the (Name of Conference) ( Date , Place and Classification of Conference) and/or for publication in EOS...Signature) CODE NS DATE COMMENTS AUtnor(s) _/ NTUF Section Head Branch Head ____________________ Robert A Arnone, 7330 Q ______________/ ______ Division

  3. Adriatic Sea Decision Support System (ADRI-DSS)

    NASA Astrophysics Data System (ADS)

    Coppini, Giovanni; Lyubartsev, Vladyslav; Pinardi, Nadia; Montanari, Giuseppe; Rinaldi, Attilio; Serra, Stefano; Santoleri, Rosalia

    2010-05-01

    The Adriatic Sea decision support system (ADRI-DSS) consists of an on-line service built upon a set of integrated operational oceanography products. ADRI-DSS integrates the Adriatic Sea monitoring and forecasting system (AFS) with local in-situ observations and is built to support the Emilia-Romagna coastal monitoring system for marine environment and ecosystem health. The target user is the Regional Environment Prevention Agency from Emilia-Romagna (Italy) called ARPA-EMR. Specifically ADRI-DSS will support the daily action of the oceanographic section of ARPA-EMR called ARPA-DAPHNE providing all the available products (forecast, observations, simulations) from Adriatic Forecasting System. The product is shaped as required by the user and moreover ADRI-DSS also integrates with the routinely observations that the user carry out on a weekly basis. The system has been designed through the interaction with ARPA-DAPHNE and consists of a online portal containing simulation and forecast for the relevant north Adriatic region. Moreover the model products are compared with in-situ observations of temperature and salinity collected by the ARPA-DAPHNE itself. In the coming future also satellite observations and indicators will be made available by ADRI-DSS. The final aim of ADRI-DSS is to integrate selected products from the AFS with the insitu and satellite observation to support the monitoring activities of ARPA-DAPNHE and to improve ARPA-DAPHNE capabilities for the Emilia-Romagna marine environment status assessment. ADRI-DSS has been developed within ECOOP project (European COastal-shelf sea OPerational Observing and forecasting system Integrated Project). ADRI-DSS is a web-based application available via internet browsers with JavaScript capability. The server part is implemented on PHP (data management) and NCL (graphics production). The NCL is NCAR Command Language, a free interpreted language designed specifically for scientific data processing and visualization, see

  4. Simulation and characterization of the Adriatic Sea mesoscale variability

    NASA Astrophysics Data System (ADS)

    Cushman-Roisin, Benoit; Korotenko, Konstantin A.; Galos, Camelia E.; Dietrich, David E.

    2007-03-01

    This paper presents simulations of the Adriatic Sea using the DieCAST model applied on a 1.2-min grid (about 2-km resolution). The simulations resolve the mesoscale variability because the grid size falls below the first baroclinic deformation radius (about 5-10 km) and DieCAST has very low horizontal dissipation. The model is initialized with seasonally averaged temperature and salinity data and forced with climatological winds and surface buoyancy fluxes (both heat flux and evaporation minus precipitation). River discharges are varied daily according to a perpetual year for every river, and the open-boundary conditions at Otranto Strait are obtained by nesting in two larger-scale models. The present simulations demonstrate that the DieCAST model allows mesoscale instabilities to develop at length scales of 5-20 km and over time scales of a few days. The simulated variability exhibits pronounced similarities with the actual mesoscale variability, in terms of location, nature and temporal evolution of the features. Meanders, swirls and eddies are noted along the relatively smooth Italian coast while offshore jets and filaments better describe the mesoscale activity along the more rugged coast of Croatia. In sum, DieCAST is highly suitable for the study of mesoscale variability in the Adriatic Sea. The present simulations also show that the seasonal hydrography of the Adriatic Sea is intrinsically unstable to mesoscale perturbations, and that the mesoscale variability along the Italian coast is the result of baroclinic instability of the Western Adriatic Current. It is shown how the properties of this instability are related to the local bottom topography.

  5. Tidal currents in the Adriatic as measured by surface drifters

    NASA Astrophysics Data System (ADS)

    Poulain, Pierre-Marie

    2013-03-01

    Velocities of surface drifters are analyzed to study tidal currents throughout the Adriatic Sea. Spectral and harmonic analyses indicate that the M2, S2, and K1 constituents dominate. Maps of tidal characteristics show that M2 and S2 are rectilinear currents (reversing tides) aligned with the main axis of the Adriatic basin with maximum amplitude (~7 cm/s for M2 and ~4 cm/s for S2) in the northern area off the Istrian Peninsula. Near the northern coast, semidiurnal tidal currents decrease in amplitude and rotate in the counterclockwise sense. Near the Po River delta, M2 (S2) motions rotate in the counterclockwise (clockwise) sense. S2 rotation is also counterclockwise near the northeastern coast. M2 phases increase from about 130° on the eastern Croatian coast to 190° on the western Italian side. S2 phases range from 150° to 200°. In the middle and southern Adriatic, the semidiurnal tides are small (~1 cm/s). The diurnal tidal currents (K1) are strong across the basin at the levels of Monte Conero and the Gargano Peninsula with speed larger than 5 cm/s and mainly clockwise rotation, and also in coastal areas (e.g., on the Albanian shelf and close to the Otranto Channel). Phases increase from the east to the west coasts (by as much as 150°). These new results compare satisfactorily with previous observations and numerical simulations, although tidal amplitudes are under-estimated with respect to mooring measurements. They extend for the first time the description of the Adriatic tidal currents to the entire basin based on direct velocity observations.

  6. Lithosphere model of the Pannonian-Adriatic overthrusting

    NASA Astrophysics Data System (ADS)

    Šumanovac, Franjo

    2015-12-01

    A gravity model has been established at the contact of the southern part of the Pannonian basin and central Dinarides. Two-dimensional gravity modelling was carried out by means of the calibrated density set, defined at the Alp07 profile (Šumanovac, 2010), which significantly improved the resolution of the method. Gravity attraction caused by the structure in the upper mantle was analyzed in detail, which enabled construction of complete lithosphere model at the contact of the Dinarides, as a part of the Adriatic microplate, and the Pannonian basin as a segment of the Eurasian plate. Geophysical models demonstrate that overthrusting structures need to be considered in the present geological model; notably, the thrusting of the Adriatic microplate under the European plate. However, overthrusting processes cannot provide a complete explanation of the processes in the Pannonian basin. Considering that the Pannonian basin area is in fact a large geothermal anomaly, it is necessary to introduce the asthenosphere upwelling into the model. The presence of this structure is confirmed by a change in densities and seismic velocities in the uppermost mantle. This process has led to a significant thinning of the crust in the Tisia block and to the homogenization of properties as a result of the rising of the asthenosphere, and the crust can therefore be considered as a single layer. The combined effect of the push exerted by the African plate, and the rising of the asthenosphere and the thinning of the crust in the Pannonian basin caused the underthrusting of the Adriatic microplate below the Pannonian segment, thickening of the crust and steeply sinking of the Adriatic upper mantle below the Dinarides. Seismicity of the area and earthquake hypocenters enable the construction of active faults, which correlate well with the main faults at the surface and boundaries of density blocks in the crust.

  7. Water, methanol and dense gas tracers in the local ULIRG Arp 220: results from the new SEPIA Band 5 Science Verification campaign

    NASA Astrophysics Data System (ADS)

    Galametz, M.; Zhang, Z.-Y.; Immer, K.; Humphreys, E.; Aladro, R.; De Breuck, C.; Ginsburg, A.; Madden, S. C.; Møller, P.; Arumugam, V.

    2016-10-01

    We present a line survey of the ultraluminous infrared galaxy Arp 220, taken with the newly installed SEPIA (Swedish-European Southern Observatory PI receiver for APEX) Band 5 instrument on APEX (Atacama Pathfinder Experiment). We illustrate the capacity of SEPIA to detect the 183.3 GHz H2O 31,3-22,0 line against the atmospheric H2O absorption feature. We confirm the previous detection of the HCN(2-1) line, and detect new transitions of standard dense gas tracers such as HNC(2-1), HCO+(2-1), CS(4-3), C34S(4-3) and HC3N(20-19). We also detect HCN(2-1) v2 = 1 and the 193.5 GHz methanol (4-3) group for the first time. The absence of time variations in the megamaser water line compared to previous observations seems to rule out an AGN nuclear origin for the line. It could, on the contrary, favour a thermal origin instead, but also possibly be a sign that the megamaser emission is associated with star-forming cores washed out in the beam. We finally discuss how the new transitions of HCN, HNC and HCO+ refine our knowledge of the interstellar medium physical conditions in Arp 220.

  8. Spawning of the colonial coral Cladocora caespitosa (Anthozoa, Scleractinia) in the Southern Adriatic Sea

    NASA Astrophysics Data System (ADS)

    Kružić, P.; Žuljević, A.; Nikolić, V.

    2008-06-01

    Data on sexual reproduction of scleractinian coral species living in temperate zones, particularly in the Mediterranean Sea, are quite scarce. This paper describes sexual reproduction of the colonial coral Cladocora caespitosa from Veliko jezero (Mljet Island) in the Adriatic Sea. Spawned orange eggs and white sperm bundles were observed on the coral bank of C. caespitosa two nights before the full moon (20 June 2005) coinciding with increasing water temperature and correlated with the lunar cycle. Spawning was observed during five nights, involving about 30% of the colonies from the coral bank. Different colonies on the bank released only one type of gamete during the reproductive period. The diameter of the sperm bundles ranged from 100 to 200 μm (average 163 μm; SD = 47.08), while the female gametes diameter ranged from 300 to 500 μm (average 416 μm; SD = 73.12).

  9. Eastern Mediterranean high resolution paleoclimate investigations using south Adriatic finely laminated sediment

    NASA Astrophysics Data System (ADS)

    Robert, B.; Jilbert, T.; de Lange, G. J.

    2009-04-01

    Sediments from the Gulf of Taranto area, southern Italy, offer the possibility to very high resolution paleo-reconstructions of the eastern Mediterranean climate variability (MOCCHA project). Riverine waters, with the Po river as its main contributor, are streaming south-eastward in the Adriatic along the eastern Italian coastline, before entering the bay of Taranto and discharging their suspended material as sediments on the shelves. Multicore GeoB 107-39-03 was taken in 2006, in the central part of the straits of Otranto, south Adriatic, on a potential monitoring site for input variability of continental waters to the Gulf of Taranto. The sediment exhibits on its total length sub-milimetric scale laminae potentially connected to high-frequency climate/hydrology variability. Conventional geochemical analyses were carried out on discrete samples (XRF, ICP-OES, organic C/N, ^13C), and a novel technique was used to investigate the sediment chemistry at the laminae scale: the sediment has been resin-impregnated to enable laser ablation coupled to ICP-MS analyses (LA-ICP-MS). This powerful method recently developed at the University of Utrecht (Jilbert et al., 2008) permits extremely high resolution geochemical profiling of the laminated sediment, to unravel the forcing mechanisms generating the laminae. Furthermore, in order to compare the data to modern days sediment geochemistry, a series of analyses were carried out on a batch of 46 surface samples, in collaboration with the MOCCHA project partners (see Posters/Talks in Euromarc session OS18). This work is supported by the EUROCORES/EUROMARC Program of the European Science Foundation (NWO.817.01.002 MOCCHA project).

  10. Flux of Nutrients Between the Middle and Southern Adriatic Sea (Gargano-Split section)

    DTIC Science & Technology

    2013-04-28

    P rather than N limited. The only exception is the northern Adriatic where high primary production and eutrophication are caused by high river...southeastern Adriatic Sea coastal strip an eutrophic area? Estuar. Coast. Shelf. Sci. 88, 395–406. http://dx.doi.org/10.1016/j.ecss.2010.04.020. Martin

  11. Vertical Structure of Bottom Ekman Tidal Flows: Observations, Theory, and Modeling From the Northern Adriatic

    DTIC Science & Technology

    2009-04-17

    STRUCTURE C01S06 Zadar Figure 1. Bathymetry of the north Adriatic and tide ellipses from vertically averaged currents. M2 ellipses are drawn in...upward toward the closed northwest end. The northern Adriatic (defined here to occupy the region northwest of Ancona and Zadar ) is the final 200

  12. Variability of the Surface Circulation and Temperature in the Adriatic Sea

    DTIC Science & Technology

    1997-09-30

    of Otranto (Fig. 3). A strong cyclonic gyre around the South Adriatic Pit was shown by two drifters. A cyclonic circulation feature at the end of the...Mare Adriatico” (PRISMA-2a) are closely related to this project. MATER Project: Surveys in the southern Adriatic and strait of Otranto (MATER, 1997

  13. Atoms in dense plasmas

    SciTech Connect

    More, R.M.

    1986-01-01

    Recent experiments with high-power pulsed lasers have strongly encouraged the development of improved theoretical understanding of highly charged ions in a dense plasma environment. This work examines the theory of dense plasmas with emphasis on general rules which govern matter at extreme high temperature and density. 106 refs., 23 figs.

  14. Ulva (Chlorophyta, Ulvales) Biodiversity in the North Adriatic Sea (Mediterranean, Italy): Cryptic Species and New Introductions.

    PubMed

    Wolf, Marion A; Sciuto, Katia; Andreoli, Carlo; Moro, Isabella

    2012-12-01

    Ulva Linnaeus (Ulvophyceae, Ulvales) is a genus of green algae widespread in different aquatic environments. Members of this genus show a very simple morphology and a certain degree of phenotypic plasticity, heavily influenced by environmental conditions, making difficult the delineation of species by morphological features alone. Most studies dealing with Ulva biodiversity in Mediterranean waters have been based only on morphological characters and a modern taxonomic revision of this genus in the Mediterranean is not available. We report here the results of an investigation on the diversity of Ulva in the North Adriatic Sea based on molecular analyses. Collections from three areas, two of which subject to intense shipping traffic, were examined, as well as historical collections of Ulva stored in the Herbarium Patavinum of the University of Padova, Italy. Molecular analyses based on partial sequences of the rbcL and tufA genes revealed the presence of six different species, often with overlapping morphologies: U. californica Wille, U. flexuosa Wulfen, U. rigida C. Agardh, U. compressa Linnaeus, U. pertusa Kjellman, and one probable new taxon. U. californica is a new record for the Mediterranean and U. pertusa is a new record for the Adriatic. Partial sequences obtained from historical collections show that most of the old specimens are referable to U. rigida. No specimens referable to the two alien species were found among the old herbarium specimens. The results indicate that the number of introduced seaweed species and their impact on Mediterranean communities have been underestimated, due to the difficulties in species identification of morphologically simple taxa as Ulva.

  15. Recent developments in understanding sea level rise at the Adriatic coasts

    NASA Astrophysics Data System (ADS)

    Tsimplis, Michael N.; Raicich, Fabio; Fenoglio-Marc, Luciana; Shaw, Andrew G. P.; Marcos, Marta; Somot, Samuel; Bergamasco, Andrea

    2010-05-01

    Sea level observations from tide-gauge records located at the Adriatic coasts are analysed. The estimated sea level trends show variability in time and space. Spatial variability is assessed by estimating the differential trends by reference to Trieste. For many of the stations the differential trends become smaller than the corresponding error bars. This indicates that the land, atmospheric and oceanic contributors to sea level change are, at long scales, uniform in the basin. Observed trends in the longer records differ significantly for the periods before 1960 and after 1960. Atmospheric forcing has been a significant contribution in sea level variability for the period 1960 onwards. The atmospheric trends account for -0.8 mm/yr for the period 1960-2000. No significant atmospheric trends appear to be present at the period 1900-1960. Changes in the atmospheric forcing alone are not capable of explaining fully the difference in the sea level trends for the periods before and after 1960. Steric trends for the period 1960-2000 have also been identified. Their magnitude depends on the depth used for their estimation. Steric trends range between -0.4 mm/yr for the upper 100 m to -2.4 mm/yr for the whole water column. The residual sea level after the removal of atmospheric and steric effects ranges between 2 to 3.4 mm/yr at various stations with an associated error bar of 1 mm/yr. This residual must be accounted for by land movements and incoming signals through the strait of Otranto. The coherence of high frequency sea level signals in the north part of the Adriatic Sea is also analysed for the period 2002-2005 using eight tide gauges. The first empirical orthogonal function contains 71% of the variability indicating that the known coherency at interannual and interdecadal scales extends partly to the higher frequency too.

  16. Recent developments in understanding sea level rise at the Adriatic coasts

    NASA Astrophysics Data System (ADS)

    Tsimplis, M. N.; Raicich, F.; Fenoglio-Marc, L.; Shaw, A. G. P.; Marcos, M.; Somot, S.; Bergamasco, A.

    Sea level observations from tide-gauge records located at the Adriatic coasts are analysed. The estimated sea level trends show variability in time and space. Spatial variability is assessed by estimating the differential trends by reference to Trieste. For many of the stations the differential trends become smaller than the corresponding error bars. This indicates that the land, atmospheric and oceanic contributors to sea level change are, at long scales, uniform in the basin. Observed trends in the longer records differ significantly for the periods before 1960 and after 1960. Atmospheric forcing has been a significant contribution in sea level variability for the period 1960 onwards. The atmospheric trends account for -0.8 mm/year for the period 1960-2000. No significant atmospheric trends appear to be present at the period 1900-1960. Changes in the atmospheric forcing alone are not capable of explaining fully the difference in the sea level trends for the periods before and after 1960. Steric trends for the period 1960-2000 have also been identified. Their magnitude depends on the depth used for their estimation. Steric trends range between -0.4 mm/year for the upper 100 m to -2.4 mm/year for the whole water column. The residual sea level after the removal of atmospheric and steric effects ranges between 2 and 3.4 mm/year at various stations with an associated error bar of 1 mm/year. This residual must be accounted for by land movements and incoming signals through the strait of Otranto. The coherence of high frequency sea level signals in the north part of the Adriatic Sea is also analysed for the period 2002-2005 using eight tide gauges. The first empirical orthogonal function contains 71% of the variability indicating that the known coherency at inter-annual and inter-decadal scales extends partly to the higher frequency too.

  17. Impacts of extreme weather events on highly eutrophic marine ecosystem (Rogoznica Lake, Adriatic coast)

    NASA Astrophysics Data System (ADS)

    Ciglenečki, I.; Janeković, I.; Marguš, M.; Bura-Nakić, E.; Carić, M.; Ljubešić, Z.; Batistić, M.; Hrustić, E.; Dupčić, I.; Garić, R.

    2015-10-01

    Rogoznica Lake is highly eutrophic marine system located on the Eastern Adriatic coast (43°32‧N, 15°58‧E). Because of the relatively small size (10,276 m2) and depth (15 m) it experiences strong natural and indirect anthropogenic influences. Dynamics within the lake is characterized by the extreme and highly variable environmental conditions (seasonal variations in salinity and temperature, water stratification and mixing, redox and euxinic conditions, concentrations of nutrients) which significantly influence the biology inside the lake. Due to the high phytoplankton activity, the upper part of the water column is well oxygenated, while hypoxia/anoxia usually occurs in the bottom layers. Anoxic part of the water column is characterized with high concentrations of sulfide (up to 5 mM) and nutrients (NH4+ up to 315 μM; PO43- up to 53 μM; SiO44- up to 680 μM) indicating the pronounced remineralization of the allochthonous organic matter, produced in the surface waters. The mixolimnion varies significantly within a season feeling effects of the Adriatic atmospheric and ocean dynamics (temperature, wind, heat fluxes, rainfall) which all affect the vertical stability and possibly induce vertical mixing and/or turnover. Seasonal vertical mixing usually occurs during the autumn/winter upon the breakdown of the stratification, injecting oxygen-rich water from the surface into the deeper layers. Depending on the intensity and duration of the vertical dynamics (slower diffusion and/or faster turnover of the water layers) anoxic conditions could developed within the whole water column. Extreme weather events such as abrupt change in the air temperature accompanied with a strong wind and consequently heat flux are found to be a key triggering mechanism for the fast turnover, introducing a large amount of nutrients and sulfur species from deeper parts to the surface. Increased concentration of nutrients, especially ammonium, phosphate, and silicates persisting for

  18. {sup 210}Pb dating of sediments from the central and the northern Adriatic Sea: The deposition and preservation of sedimentary organic carbon

    SciTech Connect

    Hamilton, T.; Fowler, S.; Miquel, J.C.; La Rosa, J.

    1996-04-01

    A central goal of the ELNA project is to assess the carbon assimilation capacity of the Northern Adriatic Sea. This requires fundamental quantitative information on budgets and sinks of organic carbon. Any change in carbon production in the water column should be reflected in the underlying sediments. Moreover, the fraction of particulate organic carbon reaching the sea floor which is subsequently preserved in the sediment will be strongly coupled to sediment accumulation and mixing. In this study a series of box cores were collected in order to characterize a hypothetical eutrophication gradient extending from the Po River outflow region in the north down to the shallow meso-Adriatic depression (Jabuka Pit). The main tasks assigned to IAEA-MEL were to provide {sup 210}Pb derived sedimentation and dry-mass accumulation rates and to examine the possible correlations between sedimentary processes, the deposition and preservation of sedimentary organic carbon and pelagic primary productivity.

  19. Towards a coastal ocean forecasting system in Southern Adriatic Northern Ionian seas based on unstructured-grid model

    NASA Astrophysics Data System (ADS)

    Federico, Ivan; Oddo, Paolo; Pinardi, Nadia; Coppini, Giovanni

    2014-05-01

    The Southern Adriatic Northern Ionian Forecasting System (SANIFS) operational chain is based on a nesting approach. The large scale model for the entire Mediterranean basin (MFS, Mediterranean Forecasting system, operated by INGV, e.g. Tonani et al. 2008, Oddo et al. 2009) provides lateral open boundary conditions to the regional model for Adriatic and Ionian seas (AIFS, Adriatic Ionian Forecasting System) which provides the open-sea fields (initial conditions and lateral open boundary conditions) to SANIFS. The latter, here presented, is a coastal ocean model based on SHYFEM (Shallow HYdrodynamics Finite Element Model) code, which is an unstructured grid, finite element three-dimensional hydrodynamic model (e.g. Umgiesser et al., 2004, Ferrarin et al., 2013). The SANIFS hydrodynamic model component has been designed to provide accurate information of hydrodynamics and active tracer fields in the coastal waters of Southern Eastern Italy (Apulia, Basilicata and Calabria regions), where the model is characterized by a resolution of about of 200-500 m. The horizontal resolution is also accurate in open-sea areas, where the elements size is approximately 3 km. During the development phase the model has been initialized and forced at the lateral open boundaries through a full nesting strategy directly with the MFS fields. The heat fluxes has been computed by bulk formulae using as input data the operational analyses of European Centre for Medium-Range Weather Forecasts. Short range pre-operational forecast tests have been performed in different seasons to evaluate the robustness of the implemented model in different oceanographic conditions. Model results are validated by means of comparison with MFS operational results and observations. The model is able to reproduce the large-scale oceanographic structures of the area (keeping similar structures of MFS in open sea), while in the coastal area significant improvements in terms of reproduced structures and dynamics are

  20. Morphometric Analysis of Major Catchments Draining the Adriatic Indenter

    NASA Astrophysics Data System (ADS)

    Robl, Jörg; Heberer, Bianca; Neubauer, Franz; Prasicek, Günther; Hergarten, Stefan

    2016-04-01

    Topography and relief in collisional orogens such as the European Alps result from the interplay of uplift driven by plate convergence and crustal shortening, and erosional surface processes that act along evolving topographic gradients and counteract topography formation. Due to ongoing indentation of the Adriatic indenter into the Eastern Alps, the eastern segment of the Adriatic indenter is one of the tectonically most active zones of the Central Mediterranean region. The region is characterized by numerous earthquakes, distinct spatial gradients in recent uplift rates and exhumation level, and active faulting. However, the predominance of carbonaceous lithology hindered low-temperature thermochronology and cosmogenic nuclide dating, so that timing, rates and drivers of south-alpine topography development are still not well constrained. Further on, a systematic morphometric analysis of rivers draining the south-alpine indenter is still missing. In this study we fill this gap and investigate the interplay of tectonics and climate by a morphometric analysis of drainage systems of the eastern segment of the Adriatic indenter. We systematically extract a variety of characteristic channel metrics of four major drainage systems (Adige, Brenta, Piave, and Tagliamento) of this domain and interpret the morphometric results in terms of (a) lithological effects such as erodibility contrasts and karstification, (b) spatially variable uplift rates, (c) base level lowering caused by glacial erosion and possible Messinian preconditioning, and (d) the migration of drainage divides. We find a clear correlation between the normalized steepness index (ksn) and bedrock type. ksn - values are systematically increased whenever rivers incise into the basement of the south-alpine indenter. However, the outcrop of the basement indicates a high level of exhumation and thus the highest overall uplift of the domain such that both increased uplift rates and low rock erodibility may be

  1. Flocculation, heavy metals (Cu, Pb, Zn) and the sand-mud transition on the Adriatic continental shelf, Italy

    USGS Publications Warehouse

    George, D.A.; Hill, P.S.; Milligan, T.G.

    2007-01-01

    Across a limited depth range (5-10 m) on many continental shelves, the dominant sediment size changes from sand to mud. This important boundary, called the sand-mud transition (SMT), separates distinct benthic habitats, causes a significant change in acoustic backscatter, represents a key facies change, and delimits more surface-reactive mud from less surface-reactive sand. With the goal of improving dynamical understanding of the SMT, surficial sediments were characterized across two SMTs on the Adriatic continental shelf of Italy. Geometric mean diameter, specific surface area (SSA), mud fraction (<63 ??m) and heavy metal concentrations were all measured. The SMT related to the Tronto River is identified between 15 and 20 m water depth while the SMT associated with the Pescara River varies between 15 and 25 m water depth. The sediment properties correlate with a new, process-based sedimentological parameter that quantifies the fraction of the sediment in the seabed that was delivered as flocs. These correlations suggest that floc dynamics exert strong influence over sediment textural properties and metal concentrations. Relative constancy in the depth of the SMT along this portion of the margin and its lack of evolution over a period during which sediment input to the margin has dramatically decreased suggest that on the Adriatic continental shelf energy is the dominant control on the depth of the SMT. ?? 2006 Elsevier Ltd. All rights reserved.

  2. Distribution and fate of legacy and emerging contaminants along the Adriatic Sea: A comparative study.

    PubMed

    Combi, Tatiane; Pintado-Herrera, Marina G; Lara-Martin, Pablo A; Miserocchi, Stefano; Langone, Leonardo; Guerra, Roberta

    2016-11-01

    The spatial distributions and fates of selected legacy and emerging compounds were investigated and compared in surface sediments sampled along the Adriatic mud-wedge and in deep-sea regions from the southern Adriatic basin. Results indicated that the concentrations of legacy contaminants (PAHs, PCBs and DDTs) and emerging contaminants (tonalide, galaxolide, EHMC, octocrylene, BP3 and NP) ranged from 0.1 to 572 ng g(-1) and from Adriatic, highlighting the importance of the Po River as the major contributor for the inputs of legacy and emerging contaminants to sediments in the Adriatic Sea. Nevertheless, the prevalence of some UV filters and fragrances in the central and southern Adriatic indicates that the proximity to tourist areas and WWTPs discharges seems to affect the distribution of those compounds. The accumulation of contaminants in the deep-sea areas supports the inference that this region may act as an important repository for contaminants within the Adriatic Sea. Estimated annual contaminant accumulation reveals that both, legacy and emerging contaminants accumulate preferentially in the northern Adriatic (40-60% of the total annual contaminant accumulation), where the presence of legacy, and to a lesser extent emerging contaminants, are likely to pose an immediate or long-term hazard to resident biota.

  3. Marine conservation and accession: the future for the Croatian Adriatic.

    PubMed

    Mackelworth, Peter; Holcer, Draško; Jovanović, Jelena; Fortuna, Caterina

    2011-04-01

    The European Union (EU) is the world's largest trading bloc and the most influential supra-national organisation in the region. The EU has been the goal for many eastern European States, for Croatia accession remains a priority and underpins many of its national policies. However, entry into the EU requires certain commitments and concessions. In October 2003 the Croatian parliament declared an ecological and fisheries protection zone in the Adriatic. Under pressure the zone was suspended, finally entering into force in March 2008 exempting EU States. There are other marine conflicts between Croatia and the EU, particularly the contested maritime border with Slovenia, and the development of the Croatian fishing fleet in opposition to the Common Fisheries Policy. Conversely, attempts to harmonise Croatian Nature Protection with the EU Habitats Directive, facilitated by pre-accession funding, has galvanised conservation policy. Since 2005 two marine protected areas have been declared, significantly increasing the marine ecosystem under protection. Finally, the development of the Marine Strategy Framework Directive is the latest EU attempt to integrate environmental policy in the maritime realm. This will have an effect not only on member States but neighbouring countries. For marine nature protection to be effective in the region the Adriatic Sea needs to be viewed as a mutually important shared and limited resource not a bargaining chip. Negotiations of the EU and Croatia have been watched closely by the other Balkan States and precedents set in this case have the potential to affect EU expansion to the East.

  4. Modeling the mesoscale variability in the Adriatic Sea

    NASA Astrophysics Data System (ADS)

    Korotenko, K. A.

    2007-06-01

    A new high-resolution (<2 km) version of the DieCAST fourth-accuracy-order model for the ocean circulation is proposed for the study of the general circulation, mesoscale structures, and their variability in the Adriatic Sea. The model uses mean seasonal data on the temperature, salinity, buoyancy fluxes, and wind. The data of the COAMPS system with a 4-km resolution were used for the simulation of the sea response to the effects of various winds: Sirocco, Maestro, and two types of boras. The mean monthly runoffs from 38 rivers and mean daily runoffs from 12 main rivers throughout the year were given in the model. The conditions at the open boundary of the Strait of Otranto were given on the basis of the hierarchy of two coarser models for the Adriatic and Mediterranean seas. Due to the extremely weak dissipation and the high resolution (the mesh size is less than the baroclinic radius of deformation, 5 10 km), the model allows one to trace the development of a baroclinic instability along the Italian coast, to simulate mesoscale structures associated with the instability, and to estimate the scales of the structures. Mesoscale filaments, meanders, mushroom-like currents, fronts, and intrusions known from satellite observations were simulated and explained. The scenario of the anomalous upwelling near the Italian coast observed in the summer of 2003 was also simulated and analyzed.

  5. Marine Conservation and Accession: The Future for the Croatian Adriatic

    NASA Astrophysics Data System (ADS)

    Mackelworth, Peter; Holcer, Draško; Jovanović, Jelena; Fortuna, Caterina

    2011-04-01

    The European Union (EU) is the world's largest trading bloc and the most influential supra-national organisation in the region. The EU has been the goal for many eastern European States, for Croatia accession remains a priority and underpins many of its national policies. However, entry into the EU requires certain commitments and concessions. In October 2003 the Croatian parliament declared an ecological and fisheries protection zone in the Adriatic. Under pressure the zone was suspended, finally entering into force in March 2008 exempting EU States. There are other marine conflicts between Croatia and the EU, particularly the contested maritime border with Slovenia, and the development of the Croatian fishing fleet in opposition to the Common Fisheries Policy. Conversely, attempts to harmonise Croatian Nature Protection with the EU Habitats Directive, facilitated by pre-accession funding, has galvanised conservation policy. Since 2005 two marine protected areas have been declared, significantly increasing the marine ecosystem under protection. Finally, the development of the Marine Strategy Framework Directive is the latest EU attempt to integrate environmental policy in the maritime realm. This will have an effect not only on member States but neighbouring countries. For marine nature protection to be effective in the region the Adriatic Sea needs to be viewed as a mutually important shared and limited resource not a bargaining chip. Negotiations of the EU and Croatia have been watched closely by the other Balkan States and precedents set in this case have the potential to affect EU expansion to the East.

  6. Spatial Distribution of Living Coccolithophores in the Southern Adriatic Sea During Late Autumn,2000.

    NASA Astrophysics Data System (ADS)

    Balestra, B.; Monechi, S.

    2001-12-01

    Water samples for coccolithophorid analyses were collected during the cruise on N/O Italica in the Southern Adriatic Sea in October 2000, from the Albanian slope to the Italian shoreline. The investigated area on the Albanian slope includes the shoreline of Gulf of the Drin to the north of the Corfù island and on the Italian shoreline from the Gulf of Manfredonia to the Capo Santa Maria di Leuca and the southern part of the Otranto Channel. The aim of this work is to understand the ecology of coccolithophorids, one of the major contributors to the carbonate sediment in the Mediterranean Sea, studying their spatial and vertical distribution, species diversity and productivity and try to determinate the relationship of this phytoplankton group with environmental parameters. Sampling was done along several transects from east to west coast (86 stations, 300 water samples). The sampling depths were planned to obtain a regular sample grid. The sampling was finer in the upper photic zone and coarser at depths where both a lower coccolithophorid concentration and species diversity have been observed. For each sampling depth the sea water was filtered on board, on Millipore acetate cellulose filters and immediately oven-dried and stored in petri-dishes. Quantitative and qualitative analyses have been performed on LM and SEM microscope. Here we report the results of 42 selected stations collected at 0m and 10m and of a transect in the southern part of the Otranto Channel. The absolute abundance of total nannoplankton varied between less than several hundreds to 1.7E05 cells/l (station 8). These values are consistent with previous studies in the eastern Mediterranean Sea (1.4E04 cells/l, Knappertbusch, 1993). The distribution and composition of the living coccolithophore communities in the Southern Adriatic Sea can be related to the environmental conditions of surface waters. 60 species have been identified at SEM. The assemblage is mainly dominated by E. huxleyi, and by

  7. Different Histories, Different Destinies‒Impact of Evolutionary History and Population Genetic Structure on Extinction Risk of the Adriatic Spined Loaches (Genus Cobitis; Cypriniformes, Actinopterygii)

    PubMed Central

    Buj, Ivana; Ćaleta, Marko; Marčić, Zoran; Šanda, Radek; Vukić, Jasna; Mrakovčić, Milorad

    2015-01-01

    The region of Balkans is often considered as an ichthyologic “hot spot”, with a great number of species and high portion of endemics living in fresh waters in a relatively small area. The Adriatic watershed in Croatia and Herzegovina is inhabited by six spined loach species (genus Cobitis) whose extinction risk estimations were based solely on their extent of occurrence (and/or area of occupancy) and its fragmentation, and conservation proposals do not consider diversity below species level. In this investigation we employed molecular genetic methods to describe present genetic structure of the Adriatic spined loaches and reveal their demographic history. The divergence of the Adriatic lineages inside the genus Cobitis started in Miocene and lasted until Pleistocene epoch. Geological events responsible for shaping recent diversity of spined loaches in the Adriatic basin are: the Dinarid Mountains upwelling, the evolution of Dinaric Lake system, local tectonic activity, river connections during glaciations and differences in sea level. Even though all the investigated species inhabit karstic rivers located in the same geographic area and that were subject of similar geological events, the results obtained reveal great differences in their genetic diversity and structure and point out the necessity of different conservation measures to ensure their future viability. High level of genetic polymorphism is characteristic for species located more to the south. Two species comprised of more than one population have completely different intraspecific structure; populations of C. illyrica are genetically distinct and represent separate evolutionary significant units, whereas intraspecific structure of C. narentana corresponds to metapopulational pattern. Without population genetic data, evolutionary significant units could be easily misidentified. Furthermore, the obtained results affirm that population genetic measurements are able to detect differences among closely

  8. Different Histories, Different Destinies‒Impact of Evolutionary History and Population Genetic Structure on Extinction Risk of the Adriatic Spined Loaches (Genus Cobitis; Cypriniformes, Actinopterygii).

    PubMed

    Buj, Ivana; Ćaleta, Marko; Marčić, Zoran; Šanda, Radek; Vukić, Jasna; Mrakovčić, Milorad

    2015-01-01

    The region of Balkans is often considered as an ichthyologic "hot spot", with a great number of species and high portion of endemics living in fresh waters in a relatively small area. The Adriatic watershed in Croatia and Herzegovina is inhabited by six spined loach species (genus Cobitis) whose extinction risk estimations were based solely on their extent of occurrence (and/or area of occupancy) and its fragmentation, and conservation proposals do not consider diversity below species level. In this investigation we employed molecular genetic methods to describe present genetic structure of the Adriatic spined loaches and reveal their demographic history. The divergence of the Adriatic lineages inside the genus Cobitis started in Miocene and lasted until Pleistocene epoch. Geological events responsible for shaping recent diversity of spined loaches in the Adriatic basin are: the Dinarid Mountains upwelling, the evolution of Dinaric Lake system, local tectonic activity, river connections during glaciations and differences in sea level. Even though all the investigated species inhabit karstic rivers located in the same geographic area and that were subject of similar geological events, the results obtained reveal great differences in their genetic diversity and structure and point out the necessity of different conservation measures to ensure their future viability. High level of genetic polymorphism is characteristic for species located more to the south. Two species comprised of more than one population have completely different intraspecific structure; populations of C. illyrica are genetically distinct and represent separate evolutionary significant units, whereas intraspecific structure of C. narentana corresponds to metapopulational pattern. Without population genetic data, evolutionary significant units could be easily misidentified. Furthermore, the obtained results affirm that population genetic measurements are able to detect differences among closely

  9. An observatory system for physical and biogeochemical parameters in the northern Adriatic Sea: the "Acqua Alta" oceanographic platform

    NASA Astrophysics Data System (ADS)

    Benetazzo, Alvise; Barbariol, Francesco; Bastianini, Mauro; Bergamasco, Andrea; Bergamasco, Filippo; Bernardi Aubry, Fabrizio; Bertotti, Luciana; Bonaldo, Davide; Cavaleri, Luigi; Carniel, Sandro; Falcieri, Francesco M.; Finotto, Stefania; Lester, Graham; Licer, Matjaz; Malacic, Vlado; Minuzzo, Tiziano; Sclavo, Mauro

    2015-04-01

    The history of the "Acqua Alta" oceanographic platform (http://www.ismar.cnr.it/infrastructures/piattaforma-acqua-alta) started more than forty years ago, shortly after the dramatic surge that affected the city of Venice in late 1966. Since then, benefiting also from recent funding acquired within the National Flagship Project RITMARE, great efforts have been devoted to monitor the oceanographic and atmospheric conditions in the Northern Adriatic Sea (NA), in the proximity of the Venice lagoon. Nowadays the "Acqua Alta", located on a 16 m depth area, represents a success story of the Institute of Marine Sciences (ISMAR) of the Italian National Research Council (CNR), that manages the structure and used collected data to improve the knowledge of the fragile sea environment that surrounds the Venetian littoral. The directional wave observations started in 1979, representing one of the world longest continuous series. On the sea surface, waves are now routinely observed by means of a submerged acoustic-Doppler system that provides burst of directional wave data, including significant wave height, mean wave period and direction of propagation. Currently these wave parameters are integrated with the data collected by a stereo-video system (namely Wave Acquisition Stereo System, WASS) that provides the 3-D profile of the wavy sea surface. WASS data are unleashing a "new view" for ocean waves providing the complete space-time dynamics of wave groups. Moreover, a series of multiparameters probes permits to measure the vertical distribution of sea temperature (at nine depths from the surface to the bottom), salinity (three positions), dissolved oxygen (two positions), and turbidity close to the sea bottom. The collected data are continuously used to track the water masses that enter, leave, and are produced within the NA. A striking example is provided by the temperature and salinity data used to follow the exceptional dense water formation that occurred in this basin

  10. High-resolution simulations of heavy precipitation events: role of the Adriatic SST and air-sea interactions

    NASA Astrophysics Data System (ADS)

    Davolio, Silvio; Stocchi, Paolo

    2016-04-01

    Strong Bora and Sirocco winds over the Adriatic Sea favour intense air-sea interactions and are often associated with heavy rainfall that affects the mountainous areas surrounding the basin. A convection-permitting model (MOLOCH) has been implemented at high resolution (2 km) in order to analyse several precipitation events over northern Italy, occurred during different seasons of the year and presenting different rainfall characteristics (stratiform, convective, orographic), and to possibly identify the relevant physical mechanisms involved. With the aim of assessing the impact of the sea surface temperature (SST) and surface fluxes on the intensity and location of the rainfall, sensitivity experiments have been performed taking into account the possible variability of SST analysis for model initialization. The model has been validated and specific diagnostic tools have been developed and applied to evaluate the vertically integrated moisture fluxes feeding the precipitating system or to compute a water balance in the atmosphere over the sea. The results show that the Adriatic Sea plays a role in determining the boundary layer characteristics through exchange of heat and moisture thus modifying the low-level flow dynamics and its interaction with the orography. This in turn impacts on the rainfall. Although the results vary among the analysed events, the precise definition of the SST and its evolution can be relevant for accurate precipitation forecasting.

  11. DENSE NONAQUEOUS PHASE LIQUIDS -- A WORKSHOP SUMMARY

    EPA Science Inventory

    site characterization, and, therefore, DNAPL remediation, can be expected. Dense nonaqueous phase liquids (DNAPLs) in the subsurface are long-term sources of ground-water contamination, and may persist for centuries before dissolving completely in adjacent ground water. In respo...

  12. Applications of remote sensing for the evaluation of Adriatic Sea environmental conditions

    SciTech Connect

    Vitiello, F.; Borfecchia, F.; De Cecco, L.; Martini, S.

    1997-08-01

    The paper shows the remote sensing activities that ENEA is carrying out for the evaluation of Adriatic Sea environmental conditions and their modifications over the last fifteen years. The activities were requested by the Italian Research Ministry to gain knowledge of the circulation model of the Adriatic Sea and to understand what caused algae blooms in some of the last years. The Adriatic Sea is a high environmental risk sea, because its depth is low and a strong pollutant charge is coming into the sea from the Po river and from many other rivers of the NE coast of Italy. Processing of satellite images has covered the period from 1980 up to now and has allowed the reconstruction of modifications of the environmental conditions of the sea. The paper shows the first results obtained by remote sensing images processing that will be utilized for the database of the Adriatic Sea.

  13. Phosphorus regeneration and burial in near-shore marine sediments (the Gulf of Trieste, northern Adriatic Sea)

    NASA Astrophysics Data System (ADS)

    Ogrinc, N.; Faganeli, J.

    2006-05-01

    According to bioassay studies and high dissolved nutrient N/P ratios in the seawater column, phosphorus (P) is thought to control marine productivity in the northern Adriatic Sea. P in near-shore marine sediments of the Gulf of Trieste, the northernmost part of the Adriatic Sea, was investigated using pore water P distributions, and benthic P flux studies under oxic and anoxic conditions. The data show that P regeneration is up to three-fold more extensive in sediments overlain by oxygen-depleted waters and proceeds in parallel with Fe and Mn enhanced benthic fluxes. It appears from the incubation experiments that degradation of sedimentary organic matter is the main contribution to the flux of P at the sediment-water interface, while the release of phosphate adsorbed on the iron oxide surface is of minor importance. It appears that about 50% of P in the Gulf of Trieste is retained within in the sediments, probably bonded to clay minerals and carbonate grains or precipitated as fluoroapatite. In these sediments total P (P tot) is preserved preferentially over organic C (C org). P regenerated from surficial sediments contributes about 1/3 of the P that is assimilated by benthic microalgae. The phytoplankton P requirement should be entirely supplied from fresh-water sources. These results suggest that oxygen depletion in coastal areas caused by eutrophication enhances P regeneration from sediments, providing the additional P necessary for increased biological productivity. The development of anoxic bottom waters in coastal areas enhances the recycling of P, exacerbating the nutrient requirement in the area. A geochemical record of P burial in a longer sedimentary sequence revealed an increasing trend of P tot and organic P (P org) contents occurring approximately 50 years BP (after 1950), probably due to increasing use of inorganic fertilizers and detergents in the area.

  14. Modeling the Northern Adriatic Double-Gyre Response to Intense Bora Wind: A Revist

    DTIC Science & Technology

    2006-12-27

    Tyrrhenian Sea and intense anticy- voked by a strong anticyclone north and northeast of the clones over northwestern Europe imparting strong pressure Alps...SUBJECT TERMS Adriatic Sea ; bora wind; modeling; validation; NCOM; QUODDY 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF 18. NUMBER 19a. NAME OF...quiet view to provide a more insightful interpretation of an all- period, the bora-wind-driven Adriatic Sea circulation recently included, long-term

  15. Relative Dispersion from a High-Resolution Coastal Model of the Adriatic Sea

    DTIC Science & Technology

    2008-01-01

    E.R., Bowen. MM.. 2006. Spatial variations of stirring in the surface ocean: a case study of the Tasman Sea . J. Phys. Oceanogr. 36, 526-542. Wiggins...a high-resolution coastal model of the Adriatic Sea Angelique C. Hazaa*, Andrew C. Pojeb, Tamay M. Ozgokmen3, Paul Martin’ " RSMASIMPO. University...relative dispersion and the distribution of finite-scale Lyapunov exponent (FSLE) fields in the Adriatic Sea . The effects of vary- ing degrees of spatial

  16. Dense array expressions

    NASA Astrophysics Data System (ADS)

    Wilson, Joseph N.; Chen, LiangMing

    1999-10-01

    Various researchers have realized the value of implementing loop fusion to evaluate dense (pointwise) array expressions. Recently, the method of template metaprogramming in C++ has been used to significantly speed-up the evaluation of array expressions, allowing C++ programs to achieve performance comparable to or better than FORTRAN for numerical analysis applications. Unfortunately, the template metaprogramming technique suffers from several limitations in applicability, portability, and potential performance. We present a framework for evaluating dense array expressions in object-oriented programming languages. We demonstrate how this technique supports both common subexpression elimination and threaded implementation and compare its performance to object-library and hand-generated code.

  17. Nematofauna in the Adriatic Sea: review and check-list of free-living nematode species

    NASA Astrophysics Data System (ADS)

    Travizi, Ana; Vidaković, Jasna

    1998-02-01

    The present paper presents a collection and synthesis of data found in numerous publications on Adriatic Sea nematofauna, as well as unpublished, data mentioned in annotations. For this purpose, a chronological order of investigations and a general survey of the species that occurred in the Adriatic Sea are given. In all, 281 free-living nematode species comprised in 133 genera and 34 families were discerned and listed in a taxonomic review, according to their spatial distribution. In special cases, descriptions of habitat features were noted. The position of species characterized by high population densities, their importance, and contribution to the faunistic composition of certain parts of the Adriatic were also discussed. The summary of the results, of prevailing research on free-living marine nematodes serves as a tool for making distinctions concerning the research level and state of nematofauna knowledge in different parts of the Adriatic Sea. Northern Adriatic nematofauna has been considerably more intensively investigated than that of the Central and South Adriatic.

  18. Mapping of decadal middle Adriatic oceanographic variability and its relation to the BiOS regime

    NASA Astrophysics Data System (ADS)

    Mihanović, Hrvoje; Vilibić, Ivica; Dunić, Natalija; Å epić, Jadranka

    2015-08-01

    We analyzed long-term time series of temperature, salinity, and dissolved oxygen (DO) concentrations collected along the Palagruža Sill transect (middle Adriatic) between 1952 and 2010. The data have been mostly collected on seasonal basis, allowing for extraction of seasonal signal from the series. By applying Self-Organizing Maps (SOM) method, a kind of unsupervised neural network method, the processes on a decadal time scale emerged as the most relevant for changes of oceanographic properties in the middle Adriatic area. Sensitivity studies revealed that oceanographic patterns obtained by SOM were not sensitive to shortening of time series, to removal of data from one station or to removal of DO from the analysis. Simultaneous SOM-based mapping of sea surface heights in the northern Ionian Sea, with these heights serving as a proxy for the Adriatic-Ionian Bimodal Oscillating System (BiOS), revealed asymmetry between anticyclonic and cyclonic BiOS patterns and correlated the decadal oscillations in the middle Adriatic with the reversals in the BiOS circulation regimes. These reversals are found to either rapidly change oceanographic properties in the middle Adriatic (e.g., during the Eastern Mediterranean Transient) or to change them with a time lag of 2-3 years. The mapped connections may be used for a short-time (a few years) forecasting of the Adriatic oceanographic properties or for mapping future climate decadal oscillations as seen by ocean climate models.

  19. Changes in the northern Adriatic molluscan community from the Holocene transgression up to the present

    NASA Astrophysics Data System (ADS)

    Gallmetzer, Ivo; Haselmair, Alexandra; Tomasovych, Adam; Stachowitsch, Michael; Zuschin, Martin

    2016-04-01

    The northern Adriatic Sea is one of the few modern, epicontinental seas comparable to typical Palaeozoic shelf environments. It has a shallow average water depth (<50 m) and was formed at the end of the last glaciation when the sea level rose. Since historical times this part of the Adriatic has been strongly influenced by human activities through multiple direct or indirect impacts (e.g. fishing, coastal building development, pollution, eutrophication, increased sedimentation), making it one of the most degraded marine ecosystems worldwide. Our study was designed to reconstruct major environmental changes here since the onset of the Holocene transgression using down-core changes in death assemblages of molluscs as indicators for ecological shifts. The sediment cores were taken at three different stations (Brijuni Islands, Croatia, off Piran, Slovenia, and off Venice, Italy), each representative of specific sediment and nutrient conditions and degrees of habitat exploitation. The cores were 1.5 m long and had diameters of 90 or 160 mm. For the molluscan shell analyses, sediment subsamples were examined for species composition, abundance, taxonomic similarity and ecological interactions (e.g. frequencies of drilling predation). In total, 98,700 valves and shells were investigated and 113 bivalve and 178 gastropod species recorded. Sedimentation rates derived from 210Pb dating are very low, between 0.15 cm/yr at Brijuni and 0.25 cm/yr at Piran. The dating of Lucinella divaricata, Timoclea ovata and Gouldia minima shells with 14C calibrated amino-acid racemisation (AAR) revealed that the cores at all three stations cover at least 6000 to 8000 years, i.e. the whole Holocene transgression period. Time averaging is high, especially in the lower core layers of Piran station, probably due to strong bioturbation. Surface mixed-layer assemblages tend to show right-skewed postmortem age-frequency distributions, whereas subsurface assemblages show unimodal or uniform shapes

  20. Relevance of the dinoflagellate Gonyaulax fragilis in mucilage formations of the Adriatic Sea.

    PubMed

    Pistocchi, Rossella; Cangini, Monica; Totti, Cecilia; Urbani, Ranieri; Guerrini, Franca; Romagnoli, Tiziana; Sist, Paola; Palamidesi, Simona; Boni, Laurita; Pompei, Marinella

    2005-12-15

    Oceanographic cruises were carried out monthly from June 1999 to July 2002 to follow the mucilage formation process in the Northern Adriatic Sea. Results show that in correspondence with these events the dinoflagellate Gonyaulax fragilis (Schütt) Kofoid was observed both in the water column and within mucilage aggregates. In the water column, increasing abundances were observed from May until July, with values never exceeding 8500 cells l(-1). Much higher densities were observed within superficial gelatinous aggregates (22800-3400000 cells l(-1)). In mucilage samples, a large number of decomposing cells were present, together with abundant alive cells, enveloped in exudates. G. fragilis isolated from mucilage samples was cultured in three different culture media; it was characterized by a low growth rate but it produced a high amount of polysaccharides. The highest yield both in terms of cell number and carbohydrate production was observed in the medium having the highest nitrogen and phosphorus content and the lowest N/P ratio. The monomeric composition of G. fragilis carbohydrates, compared with that of mucilage samples, showed that in both natural and cultured samples galactose was the most abundant sugar; in addition, an overall good correlation, especially between the monomeric carbohydrate composition of G. fragilis grown in f/2 medium and that of a mucilage sample in which this species was present in high density, was observed.

  1. Significantly Dense Two-Dimensional Hydrogen-Bond Network in a Layered Zirconium Phosphate Leading to High Proton Conductivities in Both Water-Assisted Low-Temperature and Anhydrous Intermediate-Temperature Regions.

    PubMed

    Gui, Daxiang; Zheng, Tao; Xie, Jian; Cai, Yawen; Wang, Yaxing; Chen, Lanhua; Diwu, Juan; Chai, Zhifang; Wang, Shuao

    2016-12-19

    A highly stable layered zirconium phosphate, (NH4)2[ZrF2(HPO4)2] (ZrP-1), was synthesized by an ionothermal method and contains an extremely dense two-dimensional hydrogen-bond network that is thermally stable up to 573 K, leading to combined ultrahigh water-assisted proton conductivities of 1.45 × 10(-2) S cm(-1) at 363 K/95% relative humidity and sustainable anhydrous proton conductivity of 1.1 × 10(-5) S cm(-1) at 503 K.

  2. Viscoelastic behavior of dense microemulsions

    NASA Astrophysics Data System (ADS)

    Cametti, C.; Codastefano, P.; D'arrigo, G.; Tartaglia, P.; Rouch, J.; Chen, S. H.

    1990-09-01

    We have performed extensive measurements of shear viscosity, ultrasonic absorption, and sound velocity in a ternary system consisting of water-decane-sodium di(2-ethylhexyl)sulfo- succinate(AOT), in the one-phase region where it forms a water-in-oil microemulsion. We observe a rapid increase of the static shear viscosity in the dense microemulsion region. Correspondingly the sound absorption shows unambiguous evidence of a viscoelastic behavior. The absorption data for various volume fractions and temperatures can be reduced to a universal curve by scaling both the absorption and the frequency by the measured static shear viscosity. The sound absorption can be interpreted as coming from the high-frequency tail of the viscoelastic relaxation, describable by a Cole-Cole relaxation formula with unusually small elastic moduli.

  3. Development of climate risk services under climate change scenarios in the North Adriatic coast (Italy).

    NASA Astrophysics Data System (ADS)

    Valentina, Gallina; Silvia, Torresan; Anna, Sperotto; Elisa, Furlan; Andrea, Critto; Antonio, Marcomini

    2014-05-01

    Nowadays, the challenge for coastal stakeholders and decision makers is to incorporate climate change in land and policy planning in order to ensure a sustainable integrated coastal zone management aimed at preserve coastal environments and socio-economic activities. Consequently, an increasing amount of information on climate variability and its impact on human and natural ecosystem is requested. Climate risk services allows to bridge the gap between climate experts and decision makers communicating timely science-based information about impacts and risks related to climate change that could be incorporated into land planning, policy and practice. Within the CLIM-RUN project (FP7), a participatory Regional Risk Assessment (RRA) methodology was applied for the evaluation of water-related hazards in coastal areas (i.e. pluvial flood and sea-level rise inundation risks) taking into consideration future climate change scenarios in the case study of the North Adriatic Sea for the period 2040-2050. Specifically, through the analysis of hazard, exposure, vulnerability and risk and the application of Multi-Criteria Decision Analysis (MCDA), the RRA methodology allowed to identify and prioritize targets (i.e. residential and commercial-industrial areas, beaches, infrastructures, wetlands, agricultural typology) and sub-areas that are more likely to be affected by pluvial flood and sea-level rise impacts in the same region. From the early stages of the climate risk services development and application, the RRA followed a bottom-up approach taking into account the needs, knowledge and perspectives of local stakeholders dealing with the Integrated Coastal Zone Management (ICZM), by means of questionnaires, workshops and focus groups organized within the project. Specifically, stakeholders were asked to provide their needs in terms of time scenarios, geographical scale and resolution, choice of receptors, vulnerability factors and thresholds that were considered in the

  4. Historical ecology of the northern Adriatic Sea: Field methods and coring device

    NASA Astrophysics Data System (ADS)

    Haselmair, Alexandra; Gallmetzer, Ivo; Tomasovych, Adam; Stachowitsch, Michael; Zuschin, Martin

    2014-05-01

    For an ongoing study on the historical ecology of the northern Adriatic Sea, the objective was to retrieve a high number of sediment cores at seven sampling stations spread across the entire basin. One set of cores is intended for sediment analyses including radiometric Pb-sediment-dating, grain size, TOC, TAC and heavy metal analyses. The other set of cores delivered enough shelly remains of endo- or epibenthic hard part producers (e.g. molluscs, crustaceans, echinoderms) to enable the reconstruction of death assemblages in core layers from top to bottom. The down-core changes of such assemblages record ecological shifts in a marine environment that has endured strong human impacts over several centuries. A 1.5 m-long core could, according to the available sedimentation data for the area, cover up to 2000 or even more years of ecological history. The coring method had to meet the following requirements: a) deliver 1.5-m-long cores from different sediment settings (mud to sand, reflecting a wide range of benthic habitats in the northern Adriatic); b) enable quick and easy deployment to ensure that multiple cores can be taken at the individual sampling stations within a short time; c) be relatively affordable and allow handling by the researchers themselves, potentially using a small vessel in order to further contain the operating costs. Two types of UWITEC™ piston corers were used to meet these requirements. A model with 90 mm of diameter (samples for sediment analysis) and another one with 160 mm, specifically designed to obtain the large amount of material needed for shell analysis, successfully delivered a total of 54 cores. The device consists of a stabilizing tripod and the interchangeable coring cylinders. It is equipped with a so-called hammer action that makes it possible, at least for the smaller cylinder, to penetrate even harder sediments. A closing mechanism of the corer retains the sediment in the cylinder upon extraction; it works either

  5. 226Ra activity in the mullet species Liza aurata and South Adriatic Sea marine.

    PubMed

    Antovic, N M; Antovic, I; Svrkota, N

    2010-08-01

    (226)Ra activity in the South Adriatic Sea-water, surface sediment, mud with detritus, seagrass (Posidonia oceanica) samples and the mullet (Mugilidae) species Liza aurata, as well as soil and sand from the Montenegrin Coast-was measured using the six-crystal gamma-coincidence spectrometer PRIPYAT-2M. The results are used for calculation of the absorbed (and annual effective) dose rates in air due to the (226)Ra gamma radiation. The absorbed dose rates ranged from 5.94 to 97.16 nGy h(-1) (soil) and from 0.65 to 7.65 nGy h(-1) (sand). In seawater (226)Ra activity is found to be from 0.08 to 0.15 Bq l(-1), while in whole L. aurata individuals from 0.58 to 1.97 Bq kg(-1). Annual intake of (226)Ra by human consumers of this fish species has been estimated to provide an effective dose of 0.006 mSv y(-1).

  6. Mobilisation processes responsible for iron and manganese contamination of groundwater in Central Adriatic Italy.

    PubMed

    Palmucci, William; Rusi, Sergio; Di Curzio, Diego

    2016-06-01

    Iron and manganese are two of the most common contaminants that exceed the threshold imposed by international and national legislation. When these contamination occurs in groundwater, the use of the water resource is forbidden for any purposes. Several studies investigated these two metals in groundwater, but research focused in the Central Adriatic area are still lacking. Thus, the objective of this study is to identify the origin of Fe and Mn contamination in groundwater and the hydrogeochemical processes that can enrich aquifers with these metals. This work is based on hydrogeochemical and multivariate statistical analysis of analytical results undertaken on soils and groundwater. Fe and Mn contamination are widespread in the alluvial aquifers, and their distribution is regulated by local conditions (i.e. long residence time, presence of peat or organic-rich fine sediments or anthropic pollution) that control redox processes in the aquifers and favour the mobilisation of these two metals in groundwater. The concentration of iron and manganese identified within soil indicates that the latter are a concrete source of the two metals. Anthropic impact on Fe and Mn contamination of groundwater is not related to agricultural activities, but on the contrary, the contribution of hydrocarbons (e.g. spills) is evident.

  7. Fragility in dense suspensions

    NASA Astrophysics Data System (ADS)

    Mari, Romain; Cates, Mike

    Dense suspensions can jam under shear when the volume fraction of solid material is large enough. In this work we investigate the mechanical properties of shear jammed suspensions with numerical simulations. In particular, we address the issue of the fragility of these systems, i.e., the type of mechanical response (elastic or plastic) they show when subject to a mechanical load differing from the one applied during their preparation history.

  8. Dense Plasma Focus Modeling

    SciTech Connect

    Li, Hui; Li, Shengtai; Jungman, Gerard; Hayes-Sterbenz, Anna Catherine

    2016-08-31

    The mechanisms for pinch formation in Dense Plasma Focus (DPF) devices, with the generation of high-energy ions beams and subsequent neutron production over a relatively short distance, are not fully understood. Here we report on high-fidelity 2D and 3D numerical magnetohydrodynamic (MHD) simulations using the LA-COMPASS code to study the pinch formation dynamics and its associated instabilities and neutron production.

  9. VHR Reconstruction of a Portion of Late Holocene Transgressive Adriatic System Tract

    NASA Astrophysics Data System (ADS)

    Moscon, Giorgia; Correggiari, Annamaria; Remia, Alessandro; Stefani, Cristina; Fontana, Alessandro

    2014-05-01

    The Adriatic Sea is an epicontinental semi-enclosed basin characterized by a very low axial gradient shelf in the northern and central part and by a steeper gradient in the southern sector. During the last sea-level cycle in the Adriatic basin were deposited 1) low-stand deposits formed during the Last Glacial Maximum (LGM), 2) transgressive deposits formed during the last relative sea-level rise and 3) high-stand deposits confined in a narrow belt parallel to the modern shore-line. Across the low-gradient northern shelf, the stepwise, high-amplitude last relative sea-level rise favoured the deposition and in-place drowning of different generations of transgressive barrier-lagoon systems. Where present, the paralic transgressive deposits rest on a transgressive surface and are topped by a wave ravinement surface (Cattaneo and Steel, 2003). The transgressive deposits located south of the Po delta, offshore Ravenna show a dominant longshore trend similar to the modern sea-level high-stand deposits. These bodies are wreak of ancient coastal wedges drowned in place and consist in well sorted sand capped by ravinement surface and frequently drapped by a thin veneer of high-stand mud. In recent years, the study of the transgressive deposits has focused on the quality and the amount of sand for beaches nourishment. A stratigraphic characterization of one transgressive deposit at 33 m depth was carried out in order to understand its evolution before and during the last sea-level rise and define its sand content. 765 Km of very high resolution seismic profiles were acquired at 33 w.d. during NAD12 oceanographic cruise to increase the knowledge in a known shelf area. In each profiles the transgressive surface (ts) has been traced correlating the dated peat layers from published data and it has been digitized through SeisPrho which is an interactive software for processing and interpreting high-resolution seismic reflection profiles. Data processing defined a transgressive

  10. Lunar-induced reproductive patterns in transitional habitats: Insights from a Mediterranean killifish inhabiting northern Adriatic saltmarshes

    NASA Astrophysics Data System (ADS)

    Cavraro, Francesco; Varin, Cristiano; Malavasi, Stefano

    2014-02-01

    Estuaries and coastal lagoons play a key role in the functioning of coastal ecosystems and represent important natural areas for fish communities. Species living in these habitats often show specialised ecological and life history traits. The reproductive periodicity of a northern population of the Mediterranean killifish Aphanius fasciatus was assessed using the male courtship behaviour as indicator of reproductive motivation under laboratory conditions. Timing of egg development was also checked to further support the existence of a tidal-related periodicity. Using a statistical model applied to the intensity of courtship behaviour measured over a two-month period, a semilunar periodicity was revealed, with two main peaks corresponding with full moons. Both behaviours and timing of egg development were consistent with a periodicity of 14 days, suggesting that the tidal cycle drives the reproduction of A. fasciatus in Northern Adriatic saltmarshes. The findings are assessed with a comparative approach within both European and North American transitional waters.

  11. Delta growth and river valleys: the influence of climate and sea level changes on the South Adriatic shelf (Mediterranean Sea)

    NASA Astrophysics Data System (ADS)

    Maselli, V.; Trincardi, F.; Asioli, A.; Ceregato, A.; Rizzetto, F.; Taviani, M.

    2014-09-01

    Incised valleys across continental margins represent the response of fluvial systems to changes in their equilibrium dynamics, mainly driven by base level fall forced by glacial-eustatic cycles. The Manfredonia Incised Valley formed during the last glacial sea level lowstand, when most of the southern Adriatic shelf was sub-aerially exposed but the outer shelf remained under water. The pronounced upstream deepening of the valley is ascribed to river incision of the MIS5e highstand coastal prism and related subaqueous clinoform under the influence of MIS5-4 sea level fluctuations, while the downstream shallowing and narrowing mainly reflects the impact of increased rates of sea level fall at the MIS3-2 transition on a flatter mid-outer shelf. Until 15 ka BP, the valley fed an asymmetric delta confined to the mid-outer shelf, testifying that continental and deep marine systems remained disconnected during the lowstand. Sea level rise reached the inner shelf during the Early Holocene, drowning the valley and leading to the formation of a sheltered embayment confined toward the land: at this time part of the incision remained underfilled with a marked bathymetric expression. This mini-basin was rapidly filled by sandy bayhead deltas, prograding from both the northern and southern sides of the valley. In this environment, protected by marine reworking and where sediment dispersal was less effective, the accommodation space was reduced and autogenic processes forced the formation of multiple and coalescing delta lobes. Bayhead delta progradations occurred in few centuries, between 8 and 7.2 ka cal BP, confirming the recent hypothesis that in this area the valley was filled during the formation of sapropel S1. This proximal valley fill, representing the very shallow-water equivalent of the cm-thick sapropel layers accumulated offshore in the deeper southern Adriatic basin, is of key importance in following the signature of the sapropel in a facies-tract ideally from the

  12. Estimation of sedimentation rate in the Middle and South Adriatic Sea using 137Cs.

    PubMed

    Petrinec, Branko; Franic, Zdenko; Ilijanic, Nikolina; Miko, Slobodan; Strok, Marko; Smodis, Borut

    2012-08-01

    (137)Cs activity concentrations were studied in the sediment profiles collected at five locations in the Middle and South Adriatic. In the sediment profiles collected from the South Adriatic Pit, the deepest part of the Adriatic Sea, two (137)Cs peaks were identified. The peak in the deeper layer was attributed to the period of intensive atmospheric nuclear weapon tests (early 1960s), and the other to the Chernobyl nuclear accident (1986). Those peaks could be used to estimate sedimentation rates by relating them to the respective time periods. Grain-size analysis showed no changes in vertical distribution through the depth of the sediment profile, and these results indicate uniform sedimentation, as is expected in deeper marine environments. It was not possible to identify respective peaks on more shallow locations due to disturbance of the seabed either by trawlers (locations PalagruŽa and Jabuka) or by river sediment (location Albania). The highest sedimentation rates were found in Albania (∼4 mm y(-1)) and Jabuka (3.1 mm y(-1)). For PalagruŽa, the sedimentation rate was estimated to be 1.8 mm y(-1), similar to the South Adriatic Pit where the sedimentation rate was estimated to be 1.8±0.5 mm y(-1). Low sedimentation rates found for the Middle and South Adriatic Sea are consistent with previously reported results for the rest of the Mediterranean.

  13. Microbial pollution indicators and culturable heterotrophic bacteria in a Mediterranean area (Southern Adriatic Sea Italian coasts)

    NASA Astrophysics Data System (ADS)

    Stabili, L.; Cavallo, R. A.

    2011-05-01

    In the present study we evaluated the degree of microbial water pollution along the coast line between Brindisi and Santa Maria di Leuca (Southern Adriatic Sea) as well as the culturable heterotrophic bacteria abundances and biodiversity in relation to the microbiological quality of the water. A total of 3773 colonies were isolated, subcultured and identified by several morphological, cultural and biochemical methods including the standardized API 20 E and API 20 NE tests. Along the examined coastal tract the microbial pollution indicators were always below the tolerance limits for bathing waters defined by the CEE directive, suggesting a good sanitary quality. Concerning culturable heterotrophic bacteria, different temporal density trends were observed in the four sites in relation to their geographical position. A positive relationship between the bacterial abundances and the temperature was observed in S. Cataldo and Otranto. The culturable bacterial community was mainly composed of the genera Aeromonas, Pseudomonas, Photobacterium and Flavobacterium. The Enterobacteriaceae family represented a conspicuous component of the bacterial community too. Bacilli were predominant among the Gram-positive bacteria. Of interest is the isolation of yeasts (2% at the surface and 1% at the bottom) taking into account their capability of biodegradation of various materials. Because of the low level of microbial pollution recorded, our results are indicative of the natural variation and diversity of the culturable bacterial community in such an oligotrophic ecosystem and could represent a good point of comparison with other ecosystems as well as a baseline for long term studies aimed to evaluate the effects of environmental fluctuations and human impacts on this aspect of biodiversity in coastal areas.

  14. Triassic oils and related hydrocarbon kitchens in the Adriatic basin

    SciTech Connect

    Novelli, L.; Demaison, G. )

    1988-08-01

    Without exception, the oils from both the Abruzzi basin and Albanian foredeep are of lower Liassic to Upper Triassic origin. This is demonstrated by biological marker-based correlations between the oils and stratigraphically controlled, carbonate-rich source rocks. The biomarker studies also provided proof to conclude that many of the oils possess low API gravities and high sulfur contents because they are immature rather than biodegraded. Following the geochemical investigations, a computer-aided, basinwise maturation simulation of the hydrocarbon kitchens was carried out, with backstripping in geologic time. The simulations, performed with the Tissot-Espitalie kinetic model, used basin-specific kerogen activation energies obtained by the optimum method. These simulated values were calibrated with observed values in deep wells. Two characteristics diverge from normal petroleum basin situations (e.g., the North Sea basin): sulfur-rich kerogens in the source rocks, featuring relatively low activation energy distributions, and low geothermal gradients in the subsurface. The geographic outlines of simulated Triassic-lower Liassic hydrocarbon kitchens closely coincide with the zones of petroleum occurrence and production in the Adriatic basin. Furthermore, API gravities of the oils are broadly predicted by the mathematical simulations. This methodology has once again shown its ability to rationally high-grade the petroleum-rich sectors of sedimentary basin while identifying those areas where chances of success are extremely low regardless of the presence of structures.

  15. Prokaryotic dynamics and heterotrophic metabolism in a deep convection site of Eastern Mediterranean Sea (the Southern Adriatic Pit)

    NASA Astrophysics Data System (ADS)

    Azzaro, M.; La Ferla, R.; Maimone, G.; Monticelli, L. S.; Zaccone, R.; Civitarese, G.

    2012-08-01

    We report on investigations of prokaryotic abundance, biomass, extracellular enzymatic activity, prokaryotic heterotrophic production and respiration in the full water column (˜1200 m) of a deep convection site (the Southern Adriatic Pit), carried out on six cruises in 2006-2008. Prokaryotic abundance (PA) varied vertically and temporally and ranged from 1.2 to 20.4×105 cell ml-1. Cell volumes, generally increased with depth; the lowest mean cell volume was observed in a period with no active convective process (Feb-07) and the highest in a period of stratification (Jun-08) following the convection process occurred in Feb-08. Prokaryotic biomass decreased with the depth and was related with both seasonal cycles of organic matter and hydrological processes. The picophytoplankton ranged in the upper layer (UL) from 0.089 to 10.71×104 cell ml-1. Cells were also recorded till 500 m depth in Feb-08 and this finding could be linked to water convection occurred in the Southern Adriatic Pit in that month. In UL the variations of enzymatic activities as well as leucine-aminopeptidase/ß-glucosidase ratio showed a seasonal trend probably linked to the productive processes of the photic layer. An inverse relation between alkaline phosphatase activity (APA) and phosphate concentrations was found (APA=0.0003PO4-1.7714, R2=0.333, P<0.05). Generally cell-specific enzymatic activities increased with depth as did cell-specific carbon dioxide production rates, while cell-specific prokaryotic heterotrophic production had an opposite trend. High values of prokaryotic growth efficiency registered in the deep layers in Nov-06 reflected a supply of preformed C transported within the deep water masses. Overall, in 2007 when no convective phenomenon was observed, the variability of prokaryotic metabolism was governed by the seasonal cycle of the organic matter, while in Nov-06 and Jun-08 the dynamics of deep water ventilation influenced the trend along the water column of many microbial

  16. Flux and turbulence measurements at a densely built-up site in Marseille: Heat, mass (water and carbon dioxide), and momentum

    NASA Astrophysics Data System (ADS)

    Grimmond, C. S. B.; Salmond, J. A.; Oke, T. R.; Offerle, B.; Lemonsu, A.

    2004-12-01

    Eddy covariance (EC) observations above the densely built-up center of Marseille during the Expérience sur site pour contraindre les modèles de pollution atmosphérique et de transport d'émissions (ESCOMPTE) summertime measurement campaign extend current understanding of surface atmosphere exchanges in cities. The instrument array presented opportunities to address issues of the representativeness of local-scale fluxes in urban settings. Separate EC systems operated at two levels, and a telescoping tower allowed the pair to be exposed at two different sets of heights. The flux and turbulence observations taken at the four heights, stratified by wind conditions (mistral wind and sea breeze), are used to address the partitioning of the surface energy balance in an area with large roughness elements. The turbulent sensible heat flux dominates in the daytime, although the storage heat flux is a significant term that peaks before solar noon. The turbulent latent heat flux is small but not negligible. Carbon dioxide fluxes show that this central city district is almost always a source, but the vegetation reduces the magnitude of the fluxes in the afternoon. The atmosphere in such a heavily developed area is rarely stable. The turbulence characteristics support the empirical functions proposed by M. Roth.

  17. DENSE MEDIUM CYCLONE OPTIMIZATON

    SciTech Connect

    Gerald H. Luttrell; Chris J. Barbee; Peter J. Bethell; Chris J. Wood

    2005-06-30

    Dense medium cyclones (DMCs) are known to be efficient, high-tonnage devices suitable for upgrading particles in the 50 to 0.5 mm size range. This versatile separator, which uses centrifugal forces to enhance the separation of fine particles that cannot be upgraded in static dense medium separators, can be found in most modern coal plants and in a variety of mineral plants treating iron ore, dolomite, diamonds, potash and lead-zinc ores. Due to the high tonnage, a small increase in DMC efficiency can have a large impact on plant profitability. Unfortunately, the knowledge base required to properly design and operate DMCs has been seriously eroded during the past several decades. In an attempt to correct this problem, a set of engineering tools have been developed to allow producers to improve the efficiency of their DMC circuits. These tools include (1) low-cost density tracers that can be used by plant operators to rapidly assess DMC performance, (2) mathematical process models that can be used to predict the influence of changes in operating and design variables on DMC performance, and (3) an expert advisor system that provides plant operators with a user-friendly interface for evaluating, optimizing and trouble-shooting DMC circuits. The field data required to develop these tools was collected by conducting detailed sampling and evaluation programs at several industrial plant sites. These data were used to demonstrate the technical, economic and environmental benefits that can be realized through the application of these engineering tools.

  18. Dense Axion Stars

    NASA Astrophysics Data System (ADS)

    Braaten, Eric; Mohapatra, Abhishek; Zhang, Hong

    2016-09-01

    If the dark matter particles are axions, gravity can cause them to coalesce into axion stars, which are stable gravitationally bound systems of axions. In the previously known solutions for axion stars, gravity and the attractive force between pairs of axions are balanced by the kinetic pressure. The mass of these dilute axion stars cannot exceed a critical mass, which is about 10-14M⊙ if the axion mass is 10-4 eV . We study axion stars using a simple approximation to the effective potential of the nonrelativistic effective field theory for axions. We find a new branch of dense axion stars in which gravity is balanced by the mean-field pressure of the axion Bose-Einstein condensate. The mass on this branch ranges from about 10-20M⊙ to about M⊙ . If a dilute axion star with the critical mass accretes additional axions and collapses, it could produce a bosenova, leaving a dense axion star as the remnant.

  19. Dense Axion Stars

    NASA Astrophysics Data System (ADS)

    Mohapatra, Abhishek; Braaten, Eric; Zhang, Hong

    2016-03-01

    If the dark matter consists of axions, gravity can cause them to coalesce into axion stars, which are stable gravitationally bound Bose-Einstein condensates of axions. In the previously known axion stars, gravity and the attractive force between pairs of axions are balanced by the kinetic pressure. If the axion mass energy is mc2 =10-4 eV, these dilute axion stars have a maximum mass of about 10-14M⊙ . We point out that there are also dense axion stars in which gravity is balanced by the mean-field pressure of the axion condensate. We study axion stars using the leading term in a systematically improvable approximation to the effective potential of the nonrelativistic effective field theory for axions. Using the Thomas-Fermi approximation in which the kinetic pressure is neglected, we find a sequence of new branches of axion stars in which gravity is balanced by the mean-field interaction energy of the axion condensate. If mc2 =10-4 4 eV, the first branch of these dense axion stars has mass ranging from about 10-11M⊙ toabout M⊙.

  20. Dense suspension splash

    NASA Astrophysics Data System (ADS)

    Dodge, Kevin M.; Peters, Ivo R.; Ellowitz, Jake; Schaarsberg, Martin H. Klein; Jaeger, Heinrich M.; Zhang, Wendy W.

    2014-11-01

    Impact of a dense suspension drop onto a solid surface at speeds of several meters-per-second splashes by ejecting individual liquid-coated particles. Suppression or reduction of this splash is important for thermal spray coating and additive manufacturing. Accomplishing this aim requires distinguishing whether the splash is generated by individual scattering events or by collective motion reminiscent of liquid flow. Since particle inertia dominates over surface tension and viscous drag in a strong splash, we model suspension splash using a discrete-particle simulation in which the densely packed macroscopic particles experience inelastic collisions but zero friction or cohesion. Numerical results based on this highly simplified model are qualitatively consistent with observations. They also show that approximately 70% of the splash is generated by collective motion. Here an initially downward-moving particle is ejected into the splash because it experiences a succession of low-momentum-change collisions whose effects do not cancel but instead accumulate. The remainder of the splash is generated by scattering events in which a small number of high-momentum-change collisions cause a particle to be ejected upwards. Current Address: Physics of Fluids Group, University of Twente, P.O. Box 217, 7500 AE Enschede, The Netherlands.

  1. Dense Axion Stars.

    PubMed

    Braaten, Eric; Mohapatra, Abhishek; Zhang, Hong

    2016-09-16

    If the dark matter particles are axions, gravity can cause them to coalesce into axion stars, which are stable gravitationally bound systems of axions. In the previously known solutions for axion stars, gravity and the attractive force between pairs of axions are balanced by the kinetic pressure. The mass of these dilute axion stars cannot exceed a critical mass, which is about 10^{-14}M_{⊙} if the axion mass is 10^{-4}  eV. We study axion stars using a simple approximation to the effective potential of the nonrelativistic effective field theory for axions. We find a new branch of dense axion stars in which gravity is balanced by the mean-field pressure of the axion Bose-Einstein condensate. The mass on this branch ranges from about 10^{-20}M_{⊙} to about M_{⊙}. If a dilute axion star with the critical mass accretes additional axions and collapses, it could produce a bosenova, leaving a dense axion star as the remnant.

  2. Warm dense crystallography

    NASA Astrophysics Data System (ADS)

    Valenza, Ryan A.; Seidler, Gerald T.

    2016-03-01

    The intense femtosecond-scale pulses from x-ray free electron lasers (XFELs) are able to create and interrogate interesting states of matter characterized by long-lived nonequilibrium semicore or core electron occupancies or by the heating of dense phases via the relaxation cascade initiated by the photoelectric effect. We address here the latter case of "warm dense matter" (WDM) and investigate the observable consequences of x-ray heating of the electronic degrees of freedom in crystalline systems. We report temperature-dependent density functional theory calculations for the x-ray diffraction from crystalline LiF, graphite, diamond, and Be. We find testable, strong signatures of condensed-phase effects that emphasize the importance of wide-angle scattering to study nonequilibrium states. These results also suggest that the reorganization of the valence electron density at eV-scale temperatures presents a confounding factor to achieving atomic resolution in macromolecular serial femtosecond crystallography (SFX) studies at XFELs, as performed under the "diffract before destroy" paradigm.

  3. Spatial variations of particle scavenging rates within the central and northern Adriatic Sea: use of U--Th disequilibria

    SciTech Connect

    Hamilton, T. F., LLNL

    1998-04-01

    Dissolved and particlulate Thorium-234 ({sup 234}Th) were measured in near surface waters from the Central and Northern Adriatic Sea in order to gain an insight into the intensity and variability of active scavenging and particle removal processes. Dissolved {sup 234}Th to Uranium-238 ({sup 238}U) activity ratios vary from 0.21 to 0.75 and clearly imply that {sup 234}Th is being actively scavenged from sea water on a timescale of <3 months. The scavenging rate of dissolved {sup 234}Th with respect to scavenging onto particles appears to correlate with primary productivity measurements. Scavenging and rapid removal of particulate {sup 234}Th from the water column is best explained by a mechanism of zooplankton grazing and fecal pellet production. At one sight in the Jabuka Pit, particulate {sup 234}Th residence times below the pycnocline are long (30-40 days) suggesting that particles are being more readily recycled at these depths. By comparison, in a seawater profile collected near the Po outflow region, {sup 234}Th is depleted with respect to {sup 238}U through the entire water column. We conclude from this assessment that particles in waters near the Po River outflow will be more efficiently transported to bottom sediments compared with those in deeper waters over the Jabuka Pit.

  4. An ecological model of the Northern and Central Adriatic Sea: Analysis of ecosystem structure and fishing impacts

    NASA Astrophysics Data System (ADS)

    Coll, Marta; Santojanni, Alberto; Palomera, Isabel; Tudela, Sergi; Arneri, Enrico

    2007-08-01

    A trophic mass-balance model was developed to characterise the food web structure and functioning of the Northern and Central Adriatic Sea and to quantify the ecosystem impacts of fishing during the 1990s. Forty functional groups were described, including target and non-target fish and invertebrate groups, and three detritus groups (natural detritus, discards and by-catch of cetaceans and marine turtles). Results highlighted that there was an important coupling between pelagic-benthic production of plankton, benthic invertebrates and detritus. Organisms located at low and medium trophic levels, (i.e. benthic invertebrates, zooplankton and anchovy), as well as dolphins, were identified as keystone groups of the ecosystem. Jellyfish were an important element in terms of consumption and production of trophic flows within the ecosystem. The analysis of trophic flows of zooplankton and detritus groups indirectly underlined the importance of the microbial food web in the Adriatic Sea. Fishing activities inflicted notable impacts on the ecosystem during the 1990s, with a high gross efficiency of the fishery, a high consumption of fishable production, high exploitation rates for various target and non target species, a low trophic level of the catch and medium values of primary production required to sustain the fishery. Moreover, the analysis of Odum's ecological indicators highlighted that the ecosystem was in a low-medium developmental stage. Bottom trawling ( Strascico), mid-water trawling ( Volante) and beam trawling ( Rapido) fleets had the highest impacts on both target and non target ecological groups. On the contrary, purse seining ( Lampara) showed medium to low impacts on the ecosystem; cetaceans, marine turtles and sea birds were not significantly involved in competition with fishing activity.

  5. Foraminiferal assemblages and trophic state in coastal sediments of the Adriatic Sea

    NASA Astrophysics Data System (ADS)

    Sabbatini, Anna; Bonatto, Sonia; Bianchelli, Silvia; Pusceddu, Antonio; Danovaro, Roberto; Negri, Alessandra

    2012-12-01

    The environmental variables that influence the abundance and biodiversity of foraminifera in shallow-water settings are poorly understood. In order to help address this problem, we investigated abundance, biomass and biodiversity of living (as Rose-Bengal stained) benthic foraminifera together with the quantity and biochemical composition (in terms of phytopigment, protein, lipid, carbohydrate and biopolymeric carbon) of the organic matter in coastal sediments of the Central Adriatic Sea. Sediment samples were collected in the Portonovo Bay in May, July and October 2008 and February 2009, and the organic matter quantity and biochemical composition and benthic foraminiferal abundance and assemblage composition were analysed in the top 1 cm. Uni- and multi-variate analyses of variance revealed clear temporal variability of all the investigated variables as well as relationships between the composition of the foraminiferal assemblages and the quantity and quality of the food sources. The foraminiferal abundance and species composition changed significantly between the four sampling periods, reflecting the temporal (seasonal) variability in the quantity and nutritional quality of the food sources. Lipids, among all other organic compounds, explain significant portions of the variance of both foraminiferal abundance and biomass. In winter, a strong phytoplankton bloom led to an increased quantity of nutritionally available organic matter on the sea floor, which in turn was associated with a bloom of Leptohalysis scottii and Psammophaga sp. 1. These two foraminiferal species thus displayed an opportunistic behaviour in response to the pulse of organic carbon of high nutritional quality. We suggest that these species can be used as indicators of benthic eutrophication in shallow waters.

  6. Polymer Networks Produced by Marine Diatoms in the Northern Adriatic Sea

    PubMed Central

    Svetličić, Vesna; Žutić, Vera; Radić, Tea Mišić; Pletikapić, Galja; Zimmermann, Amela Hozić; Urbani, Ranieri

    2011-01-01

    Using high resolution molecular technique of atomic force microscopy, we address the extracellular polymer production of Adriatic diatom Cylindrotheca closterium analyzed at the single cell level and the supramolecular organization of gel phase isolated from the Northern Adriatic macroaggregates. Our results revealed that extracellular polysaccharides freshly produced by marine diatoms can self-assemble directly to form gel network characteristics of the macroscopic gel phase in the natural aquatorium. Based on the experiments performed with isolated polysaccharide fractions of C. closterium and of macroaggregates gel phase, we demonstrated that the polysaccharide self-assembly into gel network can proceed independent of any bacterial mediation or interaction with inorganic particles. PMID:21731556

  7. Seasonal statistics of highest sea levels along the northwestern Adriatic coast

    NASA Astrophysics Data System (ADS)

    Lamberti, A.; Masina, M.

    2012-04-01

    Joint spatial analyses of marine flood drivers may provide important insights into the assessment of the related impacts on the low-lying coastal areas of the northwestern Adriatic coast. Identification of seasonality in the highest sea levels represents a first step in performing the analysis. Seasonal variability is investigated in the long term tidal gauge series of Punta della Salute (Venezia), Molo Sartorio (Trieste) and Porto Corsini (Ravenna) and in the short and fragmentary one of Rimini for which the available historical information, extracted from Hydrological Annals and provided by ISPRA and the Institute of Marine Science - CNR of Trieste , includes data collected with different criteria (monthly high water levels, daily high and low tides, hourly values and ten-minutes records). Following Carter and Challenor (1981) the variability of extreme high sea levels is initially studied modelling monthly maxima separately with the Generalized Extreme Value (GEV) distribution, combining them to extrapolate the distribution of annual maxima and comparing the resulting curve with that derived from the canonical approach based on annual maxima series. Monthly and annual maxima have been first declustered selecting the maximum value in a 78 hrs window and, aiming to remove the effect of sea level rise and local subsidence, detrended subtracting the regularized mean sea level. After the removal of these effects, monthly and annual maxima do not exhibit a specific multi-decadal trend. The results, expressed in terms of monthly average values, show instead a uniform behaviour for the analyzed stations, characterized by a large variability of extreme sea levels throughout a year with a systematic concentration of potential dangerous events in late autumn and winter seasons. In spite of the limited extension of the Adriatic basin, the most significant historical storms responsible of disastrous impacts on coastal areas were recorded in different years from the two

  8. Pliocene-Quaternary contourite depositional system along the south-western Adriatic margin: changes in sedimentary stacking pattern and associated bottom currents

    NASA Astrophysics Data System (ADS)

    Pellegrini, Claudio; Maselli, Vittorio; Trincardi, Fabio

    2016-02-01

    The Pliocene-Quaternary history of the south-western Adriatic margin, represented by a complex contourite depositional system, records the palaeoceanography of the basin and the interactions between oceanographic processes and the uneven slope morphology that resulted from tectonic deformation. Three main stages can be recognized: (1) during the Pliocene, a giant sediment drift formed on the southern flank of the slope-transverse Gondola anticline that focused and accelerated the flow of slope-parallel bottom currents; (2) since the early to middle Pleistocene transition, a reorganization of bottom-current pathways led to a sharp change in the sedimentary architecture of the margin that became dominated by the growth of contourite deposits; (3) as of 350 ka, landward-migrating contourites on the outer shelf (less than 120 m water depth) reflect the presence of bottom currents also in shallow waters. This analysis of the sedimentary stacking pattern of the contourite depositional system that developed along the south-western Adriatic margin since the Pliocene enables disentangling the processes that controlled changes in bottom-current activity, demonstrating that bottom-current deposits constitute the bulk of depositional sequences at the Milankovitch timescale.

  9. A North Adriatic centenarian: The marine research station at Rovinj

    NASA Astrophysics Data System (ADS)

    Zavodnik, D.

    1995-03-01

    The institute in Rovinj was founded in 1891 as the field station of the Berlin Aquarium. It soon gained in scientific importance. From 1911, it was governed by various scientific bodies, such as the ‘Kaiser-Wilhelm-Gesellschaft zur Förderung der Wissenschaften’, the ‘Reale Comitato Talassografico Italiano’, and the ‘Jugoslavenska Akademija znanosti i umjetnosti’. At present, it is a department of the ‘Ruđer Bo\\vsković’ Institute, called the ‘Center for Marine Research Rovinj’. In the past hundred years, the Rovinj station experienced several ascents and declines in its development: both in the First and Second World Wars the station's scientific equipment, research vessels, library and reference collections were dispersed, and from 1945 1948 the station was closed. But in “happier” periods, rich support by the state and international bodies favoured the increase in research facilities and promoted interest among visiting scientists. The station has always been involved in studies of the Adriatic Sea, especially in its northern part. It contributed much to general knowledge of oceanography, of the physics and chemistry of the sea, but its paramount contribution is to various disciplines of marine biological sciences. Applied research, however, was most oriented to fisheries biology, especially shellfish culture, to resource studies, and, recently, to toxicology, bacteriology, eutrophication and pollution monitoring. The international approach in science and applied research was always favoured. At present, the Center is well equipped for complex coastal and offshore field- and laboratory research, and maintains facilities for graduate and postgraduate teaching. Scientific dissemination is also promoted by the public aquarium and professional meetings.

  10. Long-term ecological changes in the north Adriatic Sea: Epi-to Infauna turnover at the Brijuni islands national park

    NASA Astrophysics Data System (ADS)

    Pifeas, Iason; Gallmetzer, Ivo; Haselmair, Alexandra; Stachowitsch, Michael; Zuschin, Martin

    2015-04-01

    The northern Adriatic Sea with its densely populated coastline experienced strong anthropogenic impacts during the last centuries. The Brijuni islands at the southern tip of Istria, Croatia, are a national park since 1983 and represent a study area of special interest when comparing impacted marine areas with regions under relatively long-term protection that were able to recover from the pressure of fishing and bottom trawling. The present study is part of a project on the historical ecology of the northern Adriatic sea and focusses on long-term ecological changes and benthic community shifts as a result of anthropogenic impacts since the Holocene transgression. Several cores of 1.5 m length and a diameter of 90 mm were taken close to the main island of Brijuni and sliced into smaller subunits for sediment analyses and the investigation of death assemblages. Hard part remains of molluscs, crustaceans, bryozoans, echinoderms and sedentary polychaetes were analysed for species composition, abundance and indicators for high biomass epifauna. Death assemblages were compared with surface samples of the recent fauna taken at the same area by grab-sampling and by divers using a 100 x 100 cm frame. Data analyses revealed a steep increase of species abundance and diversity in the early stages of the Holocene transgression, at the very bottom of the core, followed by a steady decline, representing a major shift from a previously epibenthic to an infauna dominated community. Towards the top of the core, this trend weakens, and in the uppermost 6 cm it even reverses indicating a possible recovery of the benthic communities since the protection of the area. By correlating down-core changes in benthic community structure with sediment parameters (grain size distribution, TOC, heavy metal content, concentrations of organic pollutants) and data from radiometric sediment dating, we can further improve our understanding of the timing and the magnitude of past ecological changes and

  11. Unstructured-grid coastal ocean modelling in Southern Adriatic and Northern Ionian Seas

    NASA Astrophysics Data System (ADS)

    Federico, Ivan; Pinardi, Nadia; Coppini, Giovanni; Oddo, Paolo

    2016-04-01

    The Southern Adriatic Northern Ionian coastal Forecasting System (SANIFS) is a short-term forecasting system based on unstructured grid approach. The model component is built on SHYFEM finite element three-dimensional hydrodynamic model. The operational chain exploits a downscaling approach starting from the Mediterranean oceanographic-scale model MFS (Mediterranean Forecasting System, operated by INGV). The implementation set-up has been designed to provide accurate hydrodynamics and active tracer processes in the coastal waters of Southern Eastern Italy (Apulia, Basilicata and Calabria regions), where the model is characterized by a variable resolution in range of 50-500 m. The horizontal resolution is also high in open-sea areas, where the elements size is approximately 3 km. The model is forced: (i) at the lateral open boundaries through a full nesting strategy directly with the MFS (temperature, salinity, non-tidal sea surface height and currents) and OTPS (tidal forcing) fields; (ii) at surface through two alternative atmospheric forcing datasets (ECMWF and COSMOME) via MFS-bulk-formulae. Given that the coastal fields are driven by a combination of both local/coastal and deep ocean forcings propagating along the shelf, the performance of SANIFS was verified first (i) at the large and shelf-coastal scales by comparing with a large scale CTD survey and then (ii) at the coastal-harbour scale by comparison with CTD, ADCP and tide gauge data. Sensitivity tests were performed on initialization conditions (mainly focused on spin-up procedures) and on surface boundary conditions by assessing the reliability of two alternative datasets at different horizontal resolution (12.5 and 7 km). The present work highlights how downscaling could improve the simulation of the flow field going from typical open-ocean scales of the order of several km to the coastal (and harbour) scales of tens to hundreds of meters.

  12. Evaluation of genetic diversity and root traits of sea beet accessions of the Adriatic Sea coast

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Thirty nine sea beet [Beta vulgaris L. subsp. maritima (L.) Arcang.] accessions of the Adriatic coast were screened genetically and for their adaptive morpho-functional root traits in order to identify new sources of abiotic resistances for sugar beet breeding programs. Genetic diversity was evaluat...

  13. Polychlorinated biphenyls (PCBs) in sediments from the western Adriatic Sea: Sources, historical trends and inventories.

    PubMed

    Combi, Tatiane; Miserocchi, Stefano; Langone, Leonardo; Guerra, Roberta

    2016-08-15

    Sources, historical trends and inventories of polychlorinated biphenyls (PCBs) were investigated in sediments collected in five transects along the north-south axis of the western Adriatic Sea. The concentration of total PCBs (∑28 PCBs) ranged from Adriatic Sea. This is further corroborated by the estimated inventories of PCBs, which were ~4-7 times higher in the Po River prodelta (256ngcm(-2)) in comparison to the middle and southern Adriatic, respectively, and about 100 times higher than the in the deep Adriatic Sea.

  14. Ariel's Densely Pitted Surface

    NASA Technical Reports Server (NTRS)

    1986-01-01

    This mosaic of the four highest-resolution images of Ariel represents the most detailed Voyager 2 picture of this satellite of Uranus. The images were taken through the clear filter of Voyager's narrow-angle camera on Jan. 24, 1986, at a distance of about 130,000 kilometers (80,000 miles). Ariel is about 1,200 km (750 mi) in diameter; the resolution here is 2.4 km (1.5 mi). Much of Ariel's surface is densely pitted with craters 5 to 10 km (3 to 6 mi) across. These craters are close to the threshold of detection in this picture. Numerous valleys and fault scarps crisscross the highly pitted terrain. Voyager scientists believe the valleys have formed over down-dropped fault blocks (graben); apparently, extensive faulting has occurred as a result of expansion and stretching of Ariel's crust. The largest fault valleys, near the terminator at right, as well as a smooth region near the center of this image, have been partly filled with deposits that are younger and less heavily cratered than the pitted terrain. Narrow, somewhat sinuous scarps and valleys have been formed, in turn, in these young deposits. It is not yet clear whether these sinuous features have been formed by faulting or by the flow of fluids.

    JPL manages the Voyager project for NASA's Office of Space Science.

  15. Mercury's Densely Cratered Surface

    NASA Technical Reports Server (NTRS)

    1974-01-01

    Mariner 10 took this picture (FDS 27465) of the densely cratered surface of Mercury when the spacecraft was 18,200 kilometers (8085 miles) from the planet on March 29. The dark line across top of picture is a 'dropout' of a few TV lines of data. At lower left, a portion of a 61 kilometer (38 mile) crater shows a flow front extending across the crater floor and filling more than half of the crater. The smaller, fresh crater at center is about 25 kilometers (15 miles) in diameter. Craters as small as one kilometer (about one-half mile) across are visible in the picture.

    The Mariner 10 mission, managed by the Jet Propulsion Laboratory for NASA's Office of Space Science, explored Venus in February 1974 on the way to three encounters with Mercury-in March and September 1974 and in March 1975. The spacecraft took more than 7,000 photos of Mercury, Venus, the Earth and the Moon.

    Image Credit: NASA/JPL/Northwestern University

  16. Regional prospectivity of Mesozoic and Tertiary in the eastern Adriatic and adjacent area

    SciTech Connect

    Scott, J.; Dolan, P.; Lunn, G. )

    1988-08-01

    Post-Hercynian deposits in the eastern Adriatic and the adjacent external zones of the Dinarides and Albanian Hellenides may be subdivided into four facies groups. (1) Permian-Lower Triassic clastics and carbonates with some evaporites, (2) Middle Triassic-lower Tertiary carbonate platform facies with associated continental margin deeper marine sequences, (3) Upper Cretaceous-lower Tertiary flysch, and (4) middle Tertiary molasse and postorogenic Neogene sediments. The Permian to lower Tertiary section was deposited during the complex Alpine cycle, while the upper Tertiary section is the product of post-Alpine deposition. This depositional history during markedly different tectonic regimes creates two groups of petroleum plays in the eastern Adriatic: (1) Alpine cycle plays in the Permian to lower Tertiary in the thrust-faulted and folded foreland of Adria and (2) post-Alpine plays in upper Tertiary postorogenic or late synorogenic basins. Around the Adriatic, the post-Alpine plays have so far proved the most successful. Major production occurs in the onshore Po basin and its extension beneath the Adriatic. Some of this production is from deep Alpine-cycle reservoirs, but the bulk is from the upper Tertiary-Quaternary. Similar horizons produce onshore and offshore the central-southern Adriatic coast of Italy. Major Tertiary production also occurs to the northeast in the Pannonian basin of Yugoslavia and Hungary from Miocene and younger sequences. Onshore Albania produces significant quantities of hydrocarbons; although data are scarce, much of this production is presumably from upper Tertiary molasse or lower Tertiary flysch.

  17. Toxic element concentrations in the bottlenose (Tursiops truncatus), striped (Stenella coeruleoalba) and Risso's (Grampus griseus) dolphins stranded in eastern Adriatic Sea.

    PubMed

    Bilandžić, Nina; Sedak, Marija; Ðokić, Maja; Ðuras Gomerčić, Martina; Gomerčić, Tomislav; Zadravec, Manuela; Benić, Miroslav; Prevendar Crnić, Andrea

    2012-09-01

    Concentrations of cadmium (Cd), arsenic (As), mercury (Hg) and lead (Pb) were measured in muscle, liver and kidney of three cetacean species, the bottlenose (Tursiops truncatus), striped (Stenella coeruleoalba) and Risso's (Grampus griseus) dolphins from the Croatian waters of the Adriatic Sea. In all three dolphin species Cd levels decreased in tissues in the order: kidney > liver > muscle, while As and Pb decreased in the order: liver > kidney > muscle for striped and Risso's dolphins, but with the order reversed for liver and kidney in the bottlenose dolphin for Pb. Levels of Hg consistently followed the order: liver > muscle > kidney, with mean concentrations in the liver being 11-34 times higher than in the other tissues. The highest mean concentrations of trace elements were measured in Risso's dolphins at 14.9 μg/g wet weight, for Cd in the kidney, and concentrations in the liver of 2.41, 1,115 and 0.63 μg/g for As, Hg and Pb, respectively. Statistically significant differences between the three dolphin species were determined for Cd, Hg and Pb in liver tissues, for As in muscle and for Cd in kidney. Significant correlations of metals between tissues were determined in all three species. The results presented give an indication of the environmental condition with regard to the content of toxic metals along the eastern coast of the Adriatic Sea.

  18. Two-year study of lipophilic marine toxin profile in mussels of the North-central Adriatic Sea: First report of azaspiracids in Mediterranean seafood.

    PubMed

    Bacchiocchi, Simone; Siracusa, Melania; Ruzzi, Angela; Gorbi, Stefania; Ercolessi, Manuela; Cosentino, Maria Anna; Ammazzalorso, Patrizia; Orletti, Roberta

    2015-12-15

    Since the late 1980s, the North-central Adriatic Sea has frequently experienced blooms of harmful algal species, producing marine lipophilic toxins (MLTs) which accumulate in mussels and pose a serious threat to consumer health. Here, we present a 2-year LC-MS/MS study (2012-2014) of the MLT profile in mussels from the North-central Adriatic Sea in the context of the presence of toxic phytoplankton concentrations in seawater. Okadaic acid increased in mussels from all areas during the summer and autumn-winter periods with a rising trend between 2012 and 2014. In the same periods, Dinophysis sp. increased in abundance in seawater, but the highest densities of algae did not always coincide with the highest levels of toxins in mussels. Yessotoxins (YTXs) content in mussel increased sharply in the autumn-winter periods even exceeding the legal limit; although this accumulation did not always correlated with the YTX-producers in water (such as Lingulodinium polyedrum and Protoceratium reticulatum) a massive bloom of Gonyaulax spinifera was reported in November 2013, suggesting the role of this species in YTXs shellfish contamination. Traces of Azaspiracid 2 (AZA-2) were observed often in mussels during the study period, confirming for the first time the presence of this biotoxin in Mediterranean seafood.

  19. Seasonal changes in technological and nutritional quality of Mytilus galloprovincialis from suspended culture in the Gulf of Trieste (North Adriatic Sea).

    PubMed

    Bongiorno, Tiziana; Iacumin, Lucilla; Tubaro, Franco; Marcuzzo, Eva; Sensidoni, Alessandro; Tulli, Francesca

    2015-04-15

    Nutritional quality parameters, microbiological and technological quality indicators (condition index, meat yield and water-holding capacity) of blue mussel, Mytilus galloprovincialis, reared in the North Adriatic Sea were characterised at monthly intervals over a 1 year period. Contents of protein (7.5-11.6 g/100 g), lipid (1.0-2.2 g/100 g) and ash (2.2-3.3 g/100 g) varied significantly accordingly to condition index (6-15%). n-3 PUFAs were the predominant fatty acids (38.7-45.9% of fatty acids) and docosahesaenoic and eicosapentaenoic acids were the most abundant (167 and 93.3 mg/100 g, respectively). Glycine, glutamic and aspartic acids accounted for 40% of total amino acids. All samples exhibited limited concentrations of Cr, Mn, Ni, Cu and Zn, as well as Na. M. galloprovincialis from the North Adriatic Sea showed the highest technological and nutritional quality, considering also the inter-annual variability, in late spring, which corresponds to the period immediately before gamete release.

  20. Conductive dense hydrogen

    NASA Astrophysics Data System (ADS)

    Eremets, M.; Troyan, I.

    2012-12-01

    Hydrogen at ambient pressures and low temperatures forms a molecular crystal which is expected to display metallic properties under megabar pressures. This metal is predicted to be superconducting with a very high critical temperature Tc of 200-400 K. The superconductor may potentially be recovered metastably at ambient pressures, and it may acquire a new quantum state as a metallic superfluid and a superconducting superfluid. Recent experiments performed at low temperatures T < 100 K showed that at record pressures of 300 GPa, hydrogen remains in the molecular state and is an insulator with a band gap of appr 2 eV. Given our current experimental and theoretical understanding, hydrogen is expected to become metallic at pressures of 400-500 GPa, beyond the current limits of static pressures achievable using diamond anvil cells. We found that at room temperature and pressure > 220 GPa, new Raman modes arose, providing evidence for the transformation to a new opaque and electrically conductive phase IV. Above 260 GPa, in the next phase V, hydrogen reflected light well. Its resistance was nearly temperature-independent over a wide temperature range, down to 30 K, indicating that the hydrogen was metallic. Releasing the pressure induced the metallic phase to transform directly into molecular hydrogen with significant hysteresis at 200 GPa and 295 K. These data were published in our paper: M. I. Eremets and I. A. Troyan "Conductive dense hydrogen." Nature Materials 10: 927-931. We will present also new results on hydrogen: phase diagram with phases IV and V determined in P,T domain up to 300 GPa and 350 K. We will also discuss possible structures of phase IV based on our Raman and infrared measurements up to 300 GPa.

  1. Some New Lidar Equations for Laser Pulses Scattered Back from Optically Thick Media Such as Clouds, Dense Aerosol Plumes, Sea Ice, Snow, and Turbid Coastal Waters

    NASA Technical Reports Server (NTRS)

    Davis, Anthony B.

    2013-01-01

    I survey the theoretical foundations of the slowly-but-surely emerging field of multiple scattering lidar, which has already found applications in atmospheric and cryospheric optics that I also discuss. In multiple scattering lidar, returned pulses are stretched far beyond recognition, and there is no longer a one-to-one connection between range and return-trip timing. Moreover, one can exploit the radial profile of the diffuse radiance field excited by the laser source that, by its very nature, is highly concentrated in space and collimated in direction. One needs, however, a new class of lidar equations to explore this new phenomenology. A very useful set is derived from radiative diffusion theory, which is found at the opposite asymptotic limit of radiative transfer theory than the conventional (single-scattering) limit used to derive the standard lidar equation. In particular, one can use it to show that, even if the simple time-of-flight-to-range connection is irretrievably lost, multiply-scattered lidar light can be used to restore a unique profiling capability with coarser resolution but much deeper penetration into a wide variety of optical thick media in nature. Several new applications are proposed, including a laser bathymetry technique that should work for highly turbid coastal waters.

  2. Persistence of polycyclic aromatic hydrocarbons in sediments in the deeper area of the Northern Adriatic Sea (Mediterranean Sea).

    PubMed

    Marini, Mauro; Frapiccini, Emanuela

    2013-02-01

    The Po Valley is the most important agricultural and industrial area of Adriatic basin. In this area there are several rivers which transport polycyclic aromatic hydrocarbons (PAHs) into the sea via suspended particulate matter. This study describes the persistence of PAHs in the deep and coastal sediments of the Northern Adriatic. Different environmental conditions were studied: salinity, temperature, sunlight, sediment particle size and organic matter in sediment. The average conditions in the deep areas of the Northern Adriatic are: salinity higher than 37, temperature lower than 11 °C, darkness and clayey sediments with a high organic matter content. These conditions increase the persistence of the PAHs in the deep area of the Northern Adriatic.

  3. Increased liver apoptosis and tumor necrosis factor expression in Atlantic bluefin tuna (Thunnus thynnus) reared in the northern Adriatic Sea.

    PubMed

    Corriero, Aldo; Zupa, Rosa; Pousis, Chrysovalentinos; Santamaria, Nicoletta; Bello, Giambattista; Jirillo, Emilio; Carrassi, Michele; De Giorgi, Carla; Passantino, Letizia

    2013-06-15

    The Atlantic bluefin tuna Thunnus thynnus (ABFT) is intensely fished in the Mediterranean Sea to supply a prosperous capture-based mariculture industry. Liver apoptotic structures and tumor necrosis factor (TNF) gene expression were determined in: wild ABFT caught in the eastern Atlantic; juvenile ABFT reared in the central Adriatic Sea; juvenile ABFT reared in the northern Adriatic Sea; adult ABFT reared in the western Mediterranean. The highest density of liver apoptotic structures was found in the juveniles from the northern Adriatic. Two partial TNF cDNAs (TNF1 and TNF2) were cloned and sequenced. TNF1 gene expression was higher in juveniles than in adults. The highest expression of TNF2 was found in the juveniles from the northern Adriatic. These findings might be related to the juvenile exposure to environmental pollutants.

  4. Transit and residence times in the Adriatic Sea surface as derived from drifter data and Lagrangian numerical simulations

    NASA Astrophysics Data System (ADS)

    Poulain, P.-M.; Hariri, S.

    2013-08-01

    Statistics of transit and residence times in the Adriatic Sea surface, a semi-enclosed basin of the Mediterranean, are estimated from drifter data and Lagrangian numerical simulations. The results obtained from the drifters are generally underestimated given their short operating lifetimes (half life of ∼40 days) compared to the transit and residence times. This bias can be removed by considering a large amount of numerical particles whose trajectories are integrated over a long time (750 days) with a statistical advection-dispersion model of the Adriatic surface circulation. Numerical particles indicate that the maximum transit time to exit the basin is about 216-260 days for particles released near the northern tip of the Adriatic, and that a particle entering on the eastern Otranto Channel will typically exit on the other side of the channel after 170-185 days. A duration of 150-168 days is estimated as the residence time in the Adriatic Basin.

  5. Transit and residence times in the surface Adriatic Sea as derived from drifter data and Lagrangian numerical simulations

    NASA Astrophysics Data System (ADS)

    Poulain, P.-M.; Hariri, S.

    2013-01-01

    Statistics of transit and residence times in the surface Adriatic Sea, a semi-enclosed basin of the Mediterranean, are estimated from drifter data and Lagrangian numerical simulations. The results obtained from the drifters are generally underestimated given their short operating lifetimes (half life of ~ 40 days) compared to the transit and residence times. This bias can be removed by considering a large amount of numerical particles whose trajectories are integrated over a long time (750 days) with a statistical advection-diffusion model of the Adriatic surface circulation. Numerical particles indicate that the maximum transit time to exit the basin is about 216-260 days for objects released near the northern tip of the Adriatic, and that a particle entering on the eastern Otranto Channel will typically exit on the other side of the Channel after 170-185 days. A value of 150-168 days is estimated for the residence time in the Adriatic basin.

  6. A Coupled Atmosphere-Ocean modelling system to investigate the exceptional Winter 2012 conditions in the Northern Adriatic Sea

    NASA Astrophysics Data System (ADS)

    Ricchi, Antonio; Marcello Miglietta, M.; Benetazzo, Alvise; Warner, John C.; Zambon, Joseph B.; Bonaldo, Davide; Falcieri, Francesco M.; Bergamasco, Andrea; Sclavo, Mauro; Carniel, Sandro

    2014-05-01

    During late January and early February 2012, a persistent cyclonic circulation associated with an exceptional cold anomaly dominated the Mediterranean region. Among the resulting effects, the northern Adriatic sea basin (NA) experienced a very large energy losses, mostly related to the intense and cold Bora winds blowing from north-east. Sea water temperature along the Italian coast dropped down to 6 °C, while part of the Venice lagoon got frozen. These series of exceptionally cold air outbreak episodes, as well as their effects on the NA circulation and dense water formation, are investigated by means of the Coupled Ocean-Atmosphere-Wave-Sediment Transport (COAWST) Modeling System, where the oceanographic model ROMS, the atmospheric model WRF and the wave model SWAN are coupled via MCT. In this specific application to the NA sea configuration, lasting from January 23 to February 23, 2012, particular emphasis was devoted to the analysis of the atmosphere-ocean-waves interactions. First, we employ the "stand alone" WRF atmospheric model in 4 different modes ("zero mode", i.e. using the skin temperature from the global atmospheric model without updating in the Sea Surface Temperature (SST); "static mode", i.e. retaining the January 23 radiometer SST; "dynamic mode", updating every 6 hours the SST as derived from radiometer data at 0.83 deg resolution; "OML mode", as above, but using a simple Ocean Mixed Layer model available within WRF to predict the temperature evolution). Second, the WRF-ROMS one-way forced case is analyzed, where no feedbacks to the atmosphere are provided from the ocean model ROMS, but momentum and heat fluxes are determined by WRF model. Then, the WRF-ROMS two-way coupled case is implemented (where the atmosphere model exchanges momentum and heat, and the ocean model exchanges SST with the Atmospheric model). Finally, the WRF-ROMS-SWAN two-way coupled case for waves-ocean-atmosphere is performed, where common variables are exchanged every 1200

  7. Observed and modeled surface Lagrangian transport between coastal regions in the Adriatic Sea with implications for marine protected areas

    NASA Astrophysics Data System (ADS)

    Carlson, Daniel F.; Griffa, Annalisa; Zambianchi, Enrico; Suaria, Giuseppe; Corgnati, Lorenzo; Magaldi, Marcello G.; Poulain, Pierre-Marie; Russo, Aniello; Bellomo, Lucio; Mantovani, Carlo; Celentano, Paolo; Molcard, Anne; Borghini, Mireno

    2016-04-01

    Surface drifters and virtual particles are used to investigate transport between seven coastal regions in the central and southern Adriatic Sea to estimate the degree to which these regions function as a network. Alongshore coastal currents and cyclonic gyres are the primary circulation features that connected regions in the Adriatic Sea. The historical drifter observations span 25 years and, thus, provide estimates of transport between regions realized by the mean surface circulation. The virtual particle trajectories and a dedicated drifter experiment show that southeasterly Sirocco winds can drive eastward cross-Adriatic transport from the Italian coast near the Gargano Promontory to the Dalmatian Islands in Croatia. Southeasterly winds disrupt alongshore transport on the west coast. Northwesterly Mistral winds enhanced east-to-west transport and resulted in stronger southeastward coastal currents in the western Adriatic current (WAC) and export to the northern Ionian Sea. The central Italian regions showed strong connections from north to south, likely realized by alongshore transport in the WAC. Alongshore, downstream transport was weaker on the east coast, likely due to the more complex topography introduced by the Dalmatian Islands of Croatia. Cross-Adriatic connection percentages were higher for east-to-west transport. Cross-Adriatic transport, in general, occurred via the cyclonic sub-gyres, with westward (eastward) transport observed in the northern (southern) arms of the central and southern gyres.

  8. The influence of the Po River discharge on phytoplankton bloom dynamics along the coastline of Pesaro (Italy) in the Adriatic Sea.

    PubMed

    Penna, N; Capellacci, S; Ricci, F

    2004-02-01

    In recent years, eutrophic phenomena have frequently been reported in the Italian coastal waters of the northern Adriatic Sea. The aim of the present study was to determine that the phytoplankton blooms occurring along the Italian coastline in the area of Pesaro are caused by the Po River waters. In fact between October and December 2000 the nutrient load flushed into the sea from local rivers is not significant (phosphorus 10 tons and nitrogen 110 tons), instead N and P load from the Po River are: 650 and 8969 tons. The bloom episodes occurred during this period, at which time hypoxia developed on the sea bottom. The phytoplankton cell concentrations were 40.0 x 10(6) cells L(-1), and a significant presence of diatoms was observed. This issue is important in analysing the anthropogenic disturbances and environmental changes. The eutrophic seawater conditions were also analysed using the eutrophic index.

  9. Spatial data integration for analyzing the dynamics of Albanian Adriatic shoreline

    NASA Astrophysics Data System (ADS)

    Arapi, Luan; Nikolli, Pal; Kovaçi, Sander

    2016-04-01

    Shoreline mapping and shoreline change detection are critical subjects for coastal resource management, coastal environmental protection and sustainable coastal development and planning. Coastal changes are attracting more focus since they are important environmental indicators that directly impact coastal economic development and land management. Changes in the shape of shoreline may essentially affect the environment of the coastal zone. These may be caused by natural processes and human activities. The undertaken work focuses on analyzing the Adriatic shoreline dynamics, using spatial temporal data, by taking advantage of Geographic Informatin System (GIS) and Remote Sensing (RS). Shoreline mapping focuses on some specific issues such as mapping methods used to acquire shoreline data, models and database design used to represent shoreline in the spatial database and shoreline -change analysis methods. The study area extends from the mouth of Buna River in the north to Vlora Bay in the south covering a total length of about 220 km. Detection and future assessment of Albanian Adriatic shoreline spatial position is carried out through integration of multi scale resolution of spatial temporal data and different processing methods. We have combined topographic maps at different scales (1:75 000, 1918; 1:50 000, 1937; 1:25 000, 1960, 1986 and 1:10 000, 1995), digital aerial photographs of 2007 year, satellite images of Landsat TM, Landsat ETM+ and field observed GIS data. Generation of spatial data is carried out through vectorization process and image processing. Monitoring the dynamics of shoreline position change requires understanding the coastal processes as well as coastal mapping methods. The net rates of variations in the position of the shoreline are calculated according to transects disposed perpendicularly to the baseline and spaced equally along the coast. Analysis of the relative impact of the natural factors and human activities, it is fundamental

  10. Coastal ocean forecasting with an unstructured grid model in the southern Adriatic and northern Ionian seas

    NASA Astrophysics Data System (ADS)

    Federico, Ivan; Pinardi, Nadia; Coppini, Giovanni; Oddo, Paolo; Lecci, Rita; Mossa, Michele

    2017-01-01

    SANIFS (Southern Adriatic Northern Ionian coastal Forecasting System) is a coastal-ocean operational system based on the unstructured grid finite-element three-dimensional hydrodynamic SHYFEM model, providing short-term forecasts. The operational chain is based on a downscaling approach starting from the large-scale system for the entire Mediterranean Basin (MFS, Mediterranean Forecasting System), which provides initial and boundary condition fields to the nested system. The model is configured to provide hydrodynamics and active tracer forecasts both in open ocean and coastal waters of southeastern Italy using a variable horizontal resolution from the open sea (3-4 km) to coastal areas (50-500 m). Given that the coastal fields are driven by a combination of both local (also known as coastal) and deep-ocean forcings propagating along the shelf, the performance of SANIFS was verified both in forecast and simulation mode, first (i) on the large and shelf-coastal scales by comparing with a large-scale survey CTD (conductivity-temperature-depth) in the Gulf of Taranto and then (ii) on the coastal-harbour scale (Mar Grande of Taranto) by comparison with CTD, ADCP (acoustic doppler current profiler) and tide gauge data. Sensitivity tests were performed on initialization conditions (mainly focused on spin-up procedures) and on surface boundary conditions by assessing the reliability of two alternative datasets at different horizontal resolution (12.5 and 6.5 km). The SANIFS forecasts at a lead time of 1 day were compared with the MFS forecasts, highlighting that SANIFS is able to retain the large-scale dynamics of MFS. The large-scale dynamics of MFS are correctly propagated to the shelf-coastal scale, improving the forecast accuracy (+17 % for temperature and +6 % for salinity compared to MFS). Moreover, the added value of SANIFS was assessed on the coastal-harbour scale, which is not covered by the coarse resolution of MFS, where the fields forecasted by SANIFS

  11. Characterization and distribution of organic matter using specific physico-chemical methods: A case study of the southeast Adriatic continental and shelf slope (Albania)

    NASA Astrophysics Data System (ADS)

    Plavšić, Marta; Strmečki, Slađana; Dautović, Jelena; Vojvodić, Vjeročka; Olujić, Goran; Ćosović, Božena

    2012-05-01

    In May 2009, we characterized the organic matter in the area where Albanian shelf riverine plume waters enter the Southern Adriatic Pit region. Due to stable weather and hydrological conditions at the time of sampling a longitudinal thermal front was present around the Albanian shelf break. Our measurements point to the input of inorganic nutrients, including phosphorus (average P-PO4 concentration was 0.71 μg/L) and nitrogen (average as total inorganic nitrogen (TIN) concentration was 25.33 μg/L) due to the intrusion of Levantine Intermediate Water (LIW) through the Otranto Strait. The input of LIW brings high salinity (˜38.7) water that is poor in organic matter content. Low concentrations of dissolved organic carbon (DOC) (0.7 mg C/L) and particulate organic carbon (POC) (0.06 mg C/L), surface active substances (SAS) (in the range from 0.025 to 0.078 mg/L equiv. Triton-X-100) and copper complexing capacity (CuCC) (24 nmol Cu2+/L) were measured in the area. All the values for DOC, POC, SAS and CuCC were significantly lower in the Albanian coastal waters than in the North Adriatic. The measurable influence of the inflowing Albanian rivers was observed from the inverse dependance of the DOC concentrations and salinity data. The Albanian rivers contribute to the elevated nutrient concentrations especially those of silicate, which displayed concentrations up to 380 μg/L in the shallowest coastal station.

  12. Spherical Elementary Current Systems Method Applied to Geomagnetic Field Modeling for the Adriatic

    NASA Astrophysics Data System (ADS)

    Vujić, Eugen; Brkić, Mario

    2016-08-01

    The aim of this work was to derive an accurate regional model of geomagnetic components on the Adriatic. Data of north, east and vertical geomagnetic components at repeat stations and ground survey sites enclosing the Adriatic Sea were used to obtain a geomagnetic model at 2010.5 epoch. The core field was estimated by use of the global Enhanced Magnetic Model, while the crustal field by a mathematical technique for expanding vector systems on a sphere into basis functions, known as spherical elementary current systems method. The results of this method were presented and compared to the crustal field estimations by the Enhanced Magnetic Model. The maps of isolines of the regional model are also presented.

  13. First record of Ostreopsis cfr. ovata on macroalgae in the Northern Adriatic Sea.

    PubMed

    Monti, Marina; Minocci, Marco; Beran, Alfred; Ivesa, Ljiljana

    2007-05-01

    Ostreopsis ovata is an epiphytic potentially toxic dinoflagellate. It has a world-wide distribution, normally associated with other epiphytic or benthic dinoflagellates. In tropical seas O. ovata is often associated with the genera Gambierdiscus, Coolia and Prorocentrum, causing cinguatera fish poisoning. Recently, Ostreopsis spp. blooms in the Tyrrhenian and southern Adriatic Sea have been related to human health problems, such as breathing and skin irritation. Here we report the first record of Ostreopsis cfr. ovata in the Northern Adriatic Sea. O. cfr. ovata was isolated from macroalgae in two areas, the Gulf of Trieste (Italy) and close to Rovinj (Croatia). The microalga was identified by scanning electron microscopy and by fluorescence light microscopy. Size range and thecal pore structure were similar to those described for O. cfr. ovata in previous studies. Ostreopsis cfr. ovata was present on all the macroalgae collected, particularly browns and reds. The microalgal association on macroalgae was mostly composed of Ostreopsis sp., Coolia monotis and Coscinodiscus sp.

  14. Polybrominated diphenyl ethers in mussels (Mytilus galloprovincialis) collected from Central Adriatic Sea.

    PubMed

    Piersanti, Arianna; Tavoloni, Tamara; Bastari, Eleonora; Lestingi, Carmela; Romanelli, Sara; Saluti, Giorgio; Moretti, Simone; Galarini, Roberta

    2015-12-15

    One-hundred and thirty-four samples of mussels (Mytilus galloprovincialis) collected along Central Adriatic Sea in 2013 were examined to determine the levels of fifteen congeners of polybrominated diphenyl ethers (PBDEs). The purified samples were analysed by gas-chromatography coupled to tandem mass spectrometry (GC-MS/MS) applying the isotopic dilution. Only four congeners (PBDE 47, PBDE 99, PBDE 49 and PBDE 100) were present above the established limits of quantification with mean concentrations equal to 73, 30, 19 and 18 pg g(-1), respectively. The concentrations of PBDEs (sum) ranged from 27 to 386 pg g(-1), with the highest levels around the coastal area of Ancona town. The here found levels were comparable to those measured in mussels collected along Southern Adriatic Sea.

  15. GROUND WATER ISSUE: DENSE NONAQUEOUS PHASE LIQUIDS

    EPA Science Inventory

    This issue paper is a literature evaluation focusing on DNAPLs and provides an overview from a conceptual fate and transport point of view of DNAPL phase distribution, monitoring, site characterization, remediation, and modeling.

  16. Morphology and Species Composition of Southern Adriatic Sea Leptocephali Evaluated Using DNA Barcoding

    PubMed Central

    Anibaldi, Alessandra; Benassi Franciosi, Claudia; Massari, Francesco; Tinti, Fausto; Piccinetti, Corrado

    2016-01-01

    Leptocephali are the characteristic larvae of the superorder Elopomorpha that are difficult to identify at the species level. In this study, we used DNA barcoding (i.e. short genetic sequences of DNA used as unique species tags) coupled with classical taxonomic methods to identify leptocephali in the southern Adriatic Sea. This information will provide an assessment of the biodiversity of the eel larvae in this region. A total of 2,785 leptocephali were collected, and using external morphology were assigned to seven morphotypes: Ariosoma balearicum, Conger conger, Gnathophis mystax, Facciolella sp., Nettastoma melanurum, Dalophis imberbis and Chlopsis bicolor. Collectively, these seven morphotypes are considered to be a good proxy for the Anguilliformes community (the main order of the Elopomorpha) in the southern Adriatic Sea (to date, seven families and sixteen species have been recorded in this region). Interestingly, the higher number of G. mystax larvae collected suggests an increased abundance of this genus. To validate the morphological identifications, we sequenced 61 leptocephali (at a 655 bp fragment from the cytochrome oxidase subunit 1 mitochondrial region) and developed barcode vouchers for the seven morphotypes. Using genetic information from reference databases, we validated three of these morphotypes. Where reference sequences were unavailable, we generated barcodes for both adult and juvenile forms to provide additional genetic information. Using this integrated approach allowed us to characterize a new species of Facciolella in the Adriatic Sea for the first time. Moreover, we also revealed a lack of differentiation, at the species level, between G. mistax and G. bathytopos, a western Atlantic Ocean species. Our morphological and barcode data have been published in the Barcoding of the Adriatic Leptocephali database. This work represents the first contribution to a wider project that aims to create a barcode database to support the assessment of

  17. Offshore Adriatic marginal gas fields: An approach to the technique of reservoir development

    SciTech Connect

    Montanari, A.; Bolelli, V.; Piccoli, G.

    1986-01-01

    The application of accelerated gas blowdown and wire line techniques in reservoir development and exploitation is presented for an off-shore Adriatic marginal gas field. The approach discussed in this paper utilizes selective completion, very low reserves/production ratio, sequential production, Through Tubing Bridge Plug and Through Tubing Perforation techniques to avoid the use of costly workover rigs and to allow economically convenient exploitation of a structure which otherwise would have been abandoned.

  18. Morphology and Species Composition of Southern Adriatic Sea Leptocephali Evaluated Using DNA Barcoding.

    PubMed

    Anibaldi, Alessandra; Benassi Franciosi, Claudia; Massari, Francesco; Tinti, Fausto; Piccinetti, Corrado; Riccioni, Giulia

    2016-01-01

    Leptocephali are the characteristic larvae of the superorder Elopomorpha that are difficult to identify at the species level. In this study, we used DNA barcoding (i.e. short genetic sequences of DNA used as unique species tags) coupled with classical taxonomic methods to identify leptocephali in the southern Adriatic Sea. This information will provide an assessment of the biodiversity of the eel larvae in this region. A total of 2,785 leptocephali were collected, and using external morphology were assigned to seven morphotypes: Ariosoma balearicum, Conger conger, Gnathophis mystax, Facciolella sp., Nettastoma melanurum, Dalophis imberbis and Chlopsis bicolor. Collectively, these seven morphotypes are considered to be a good proxy for the Anguilliformes community (the main order of the Elopomorpha) in the southern Adriatic Sea (to date, seven families and sixteen species have been recorded in this region). Interestingly, the higher number of G. mystax larvae collected suggests an increased abundance of this genus. To validate the morphological identifications, we sequenced 61 leptocephali (at a 655 bp fragment from the cytochrome oxidase subunit 1 mitochondrial region) and developed barcode vouchers for the seven morphotypes. Using genetic information from reference databases, we validated three of these morphotypes. Where reference sequences were unavailable, we generated barcodes for both adult and juvenile forms to provide additional genetic information. Using this integrated approach allowed us to characterize a new species of Facciolella in the Adriatic Sea for the first time. Moreover, we also revealed a lack of differentiation, at the species level, between G. mistax and G. bathytopos, a western Atlantic Ocean species. Our morphological and barcode data have been published in the Barcoding of the Adriatic Leptocephali database. This work represents the first contribution to a wider project that aims to create a barcode database to support the assessment of

  19. Comparison of Model-Simulated and Observed Currents in the Central Adriatic During DART

    DTIC Science & Technology

    2009-01-01

    AUTHOR(S) Paul J. Martin, Jeffrey W. Book, Derek M. Burrage, Clark D. Rowley, Marina Tudor 5d. PROJECT NUMBER 5e. TASK NUMBER 5f. WORK UNIT...OF RESPONSIBLE PERSON Paul Martin 19b. TELEPHONE NUMBER (Include area code) 228-688-5447 Standard Form 298 (Rev. 8/98I Prescribed by ANSI Std...Kuzmic, and M. Wimbush (2009), Vertical structure of bottom Ekman tidal flow: Observatios, theory, and modeling from northern Adriatic, J. Geophys. Res

  20. Helminth communities in eels Anguilla anguilla from Adriatic coastal lagoons in Italy.

    PubMed

    Di Cave, D; Berrilli, F; De Liberato, C; Orecchia, P; Kennedy, C R

    2001-03-01

    The composition and diversity of the total and intestinal component and infra-communities were determined in eels Anguilla anguilla from three shallow lagoons on the Adriatic coast of Italy to determine whether the helminth communities would differ in composition and structure from those in eels from lagoons on the Tyrrhenian coast. The lagoons differed in respect of their management regimes and the extent of freshwater influx. Both freshwater and marine species of helminths were found in the eels in all three lagoons, but the freshwater component was richer in Valle Figheri. A suite of three digenean eel specialist species occurred in all three lagoons, of which any two members dominated each community. This conferred a high degree of similarity between the communities of the three lagoons. The same three species also dominated helminth communities in eels in lagoons along the Tyrrhenian coast of Italy, and compositional similarity levels were similar within and between western and eastern groups. Species richness was higher in the component communities of the eels of the Adriatic lagoons when compared to the Tyrrhenian ones, but diversity and dominance indices were of a similar order of magnitude and range. Intestinal helminth communities were richer and more diverse in two of the Adriatic lagoons because the proportion of eels with zero or one helminth species was, unusually, in the minority. It was nevertheless concluded that infracommunity structure was similar in eels from both western and eastern lagoons and that the hypothesis that it would differ in Adriatic lagoons could not be supported. The findings provide further evidence of the similarity in composition and structure of helminth communities in eels from coastal lagoons throughout Europe.

  1. Comparison of model-simulated and observed currents in the central Adriatic during DART

    NASA Astrophysics Data System (ADS)

    Martin, P. J.; Book, J. W.; Burrage, D. M.; Rowley, C. D.; Tudor, M.

    2009-02-01

    Numerical simulations of the Adriatic Sea were performed with the Navy Coastal Ocean Model (NCOM) during the Dynamics of the Adriatic in Real Time (DART) Experiments conducted between October 2005 and September 2006. Grid resolution was 1 km. Model forcing included tides, surface fluxes from the Aire Limitée Adaptation Dynamique Développement International (ALADIN) atmospheric model, relaxation to a daily satellite sea surface temperature analysis, extensive river and runoff discharges, and open boundary conditions south of Otranto specified from a global model. Currents predicted by the model were compared with currents from 12 Acoustic Doppler Current Profiler (ADCP) moorings located along a line between the Gargano Peninsula, Italy, and Split, Croatia. The nontidal comparisons were performed with detided currents. Correlations between the model and ADCP currents were highest in the Western Adriatic Current (WAC), which flows southeastward along the Italian coast. Lowest correlations were in the interior of the Adriatic, likely because of instability processes. Correlations between the ALADIN winds and the model and ADCP currents at the mooring locations were also highest in the WAC. For November 2005 through August 2006, the model and ADCP mean WAC transports were 0.321 and 0.304 Sv, respectively, with a temporal correlation of 0.79. Comparison of current variance showed best agreement near the Italian and Croatian coasts. In the interior, the NCOM current variance compared fairly well with that of the ADCPs for November-January but decreased significantly relative to the ADCPs for February-August. Spectral analyses indicate most of the difference in variance to be at periods exceeding 2 days.

  2. Characterization of aerosols above the Northern Adriatic Sea: Case studies of offshore and onshore wind conditions

    NASA Astrophysics Data System (ADS)

    Piazzola, J.; Mihalopoulos, N.; Canepa, E.; Tedeschi, G.; Prati, P.; Zarmpas, P.; Bastianini, M.; Missamou, T.; Cavaleri, L.

    2016-05-01

    Aerosol particles in coastal areas result from a complex mixing between sea spray aerosols locally generated at the sea surface by the wind-waves interaction processes and a continental component resulting from natural and/or anthropogenic sources. This paper presents a physical and chemical analysis of the aerosol data acquired from May to September 2014 in the Adriatic Sea. Aerosol distributions were measured on the Acqua Alta platform located 15 km off the coast of Venice using two Particle Measuring System probes and a chemical characterization was made using an Ion Chromatography analysis (IC). Our aim is to study both the sea-spray contribution and the anthropogenic influence in the coastal aerosol of this Mediterranean region. To this end, we focus on a comparison between the present data and the aerosol size distributions measured south of the French Mediterranean coast. For air masses of marine origin transported by southern winds on the French coast and by the Sirocco in the Adriatic, we note a good agreement between the concentrations of super-micrometer aerosols measured in the two locations. This indicates a similar sea surface production of sea-spray aerosols formed by bubble bursting processes in the two locations. In contrast, the results show larger concentrations of submicron particles in the North-Western Mediterranean compared to the Adriatic, which result probably from a larger anthropogenic background for marine conditions. In contrast, for a coastal influence, the chemical analysis presented in the present paper seems to indicate a larger importance of the anthropogenic impact in the Northern Adriatic compared to the North-Western Mediterranean.

  3. Long Waves Perturbations to Astronomical Tides in Adriatic and Tyrrenian Sea

    SciTech Connect

    Sigismondi, Costantino

    2008-01-03

    Portable tide gauges have been made with ultrasonic detectors with acquisition rate of 100 data per minute. With them we measured mean sea level variations in different locations of Adriatic and Tyrrenian sea around latitude 42 deg. N. Several long term variations are superimposed to astronomical tide, ranging from 4 to 60 minutes. Their nature of seiches or edge waves and their identification with transversal oscillations of the whole sea are discussed.

  4. Dense spray evaporation as a mixing process

    NASA Astrophysics Data System (ADS)

    de Rivas, A.; Villermaux, E.

    2016-05-01

    We explore the processes by which a dense set of small liquid droplets (a spray) evaporates in a dry, stirred gas phase. A dense spray of micron-sized liquid (water or ethanol) droplets is formed in air by a pneumatic atomizer in a closed chamber. The spray is conveyed in ambient air as a plume whose extension depends on the relative humidity of the diluting medium. Standard shear instabilities develop at the plume edge, forming the stretched lamellar structures familiar with passive scalars. Unlike passive scalars however, these lamellae vanish in a finite time, because individual droplets evaporate at their border in contact with the dry environment. Experiments demonstrate that the lifetime of an individual droplet embedded in a lamellae is much larger than expected from the usual d2 law describing the fate of a single drop evaporating in a quiescent environment. By analogy with the way mixing times are understood from the convection-diffusion equation for passive scalars, we show that the lifetime of a spray lamellae stretched at a constant rate γ is tv=1/γ ln(1/+ϕ ϕ ) , where ϕ is a parameter that incorporates the thermodynamic and diffusional properties of the vapor in the diluting phase. The case of time-dependent stretching rates is examined too. A dense spray behaves almost as a (nonconserved) passive scalar.

  5. Climate change effects on environment (marine, atmospheric and terrestrial) and human perception in an Italian Region (Marche) and the nearby northern Adriatic Sea.

    NASA Astrophysics Data System (ADS)

    Appiotti, F.; Krzelj, M.; Marincioni, F.; Russo, A.

    2012-04-01

    An integrated analysis of recent climate change, including atmosphere, sea and land, as well as some of the impacts on society, has been conducted on the Marche Region in central Italy and the northern portion of the Adriatic Sea. The Marche Region is one of the 20 administrative divisions of Italy, located at a latitude approximately 43° North, with a total surface area of 9,366 km2 and 1,565,000 residents. The northern Adriatic Sea is the northernmost area of the Mediterranean Sea, and it has peculiar relevance for several aspects (environment, tourism, fisheries, economy). The collected environmental data included meteorological stations (daily maximum and minimum air temperature, daily precipitation), oceanographic stations (sea temperature, salinity, dissolved oxygen, nutrient salts concentration, chlorophyll) and river flows, over the last 50 years. The collected social data include 800 questionnaires and interviews carried out on selected samples of residents, decision-makers and emergency managers. These questionnaires and interviews aimed at highlighting the perception of climate change risks. The trend analysis of air temperature and precipitation data detailed an overall temperature increase in all seasons and rainfall decreases in Winter, Spring and Summer with Autumn increases, influencing river flow changes. Marine data showed a relevant warming of the water column in the period after 1990 in comparison with the previous period, particularly in the cold season. Surface salinity increased in Spring and Summer and strongly decreased in Autumn and Winter (according with the precipitation and river flow changes). These last mentioned changes, combined with anthropogenic effects, also influenced the marine ecosystems, with changes of nutrient salts, chlorophyll and dissolved oxygen. Changes in nutrient discharge from rivers influenced the average marine chlorophyll concentration reduction and the consequent average reduction of warm season hypoxic

  6. Recent changes in surge-associated meteorological events in the Northern Adriatic Sea

    NASA Astrophysics Data System (ADS)

    Pirazzoli, P. A.; Tomasin, A.

    2001-05-01

    The recent increase in the frequency of coastal flooding in Venice (Italy) mainly depends on loss of soil elevation (land subsidence and eustasy) and on man-induced hydrodynamic changes in the lagoon area, but can also be strengthened in the near future by changes in climate. In this paper, after a short review of recent changes in the relative mean and maximal levels of the sea and their causes, the main meteorological factors (atmospheric pressure and winds of bora or sirocco) which produce sea surges in the Gulf of Venice are identified statistically. The recent evolution of these meteorological factors in the Adriatic area shows some favorable trends (the atmospheric pressure is increasing, thus masking provisionally eustatic sea-level rise, and bora is sharply lessening). However, the effects of sirocco, which is increasing in frequency in the central Adriatic, seem to be prevailing. On the whole, the frequency of sea surges greater or equal to 10 to 30 cm is increasing in the North Adriatic and this implies more frequent "moderately high tide levels", which are however liable to flood the lowest parts of the city of Venice.

  7. Three Anisakis spp. isolated from toothed whales stranded along the eastern Adriatic Sea coast.

    PubMed

    Blažeković, Kristina; Pleić, Ivana Lepen; Đuras, Martina; Gomerčić, Tomislav; Mladineo, Ivona

    2015-01-01

    Knowledge concerning cetacean ecology in the Mediterranean is limited but important for sustainable planning and enforcement of appropriate conservation measures. Any information that might help to elucidate their ecology is essential. We explored the population and genetic structures of Anisakis spp. nematodes isolated from four toothed whale species - bottlenose dolphins (Tursiops truncatus), striped dolphins (Stenella coeruleoalba), Risso's dolphins (Grampus griseus) and Cuvier's beaked whales (Ziphius cavirostris) - stranded along the eastern Adriatic Sea coast (1990-2012) to reveal more information on host ecological patterns. Lower parasite prevalence was observed in resident dolphin species compared with occasionally occurring species, as well as in young compared with adult dolphins, indicating different feeding habits related to age. No unequivocal relationship between the biological traits of a host (age, body length, body mass and blubber depth) and Anisakis population parameters was observed. Phylogenetic analysis revealed a new geographical record of Anisakis simplex sensu stricto (1.96%) and Anisakis physeteris (1.31%) in the Adriatic Sea in addition to resident Anisakis pegreffii (96.73%). In an assessment of the Adriatic Sea and oceans worldwide, the genetic structure of Anisakis revealed that A. pegreffii populations do not differ among various final host species but do differ with respect to geographical location in contrast to previously accepted Anisakis panmixia.

  8. A high resolution late Holocene palaeo environmental record from the central Adriatic Sea

    NASA Astrophysics Data System (ADS)

    Oldfield, F.; Asioli, A.; Accorsi, C. A.; Mercuri, A. M.; Juggins, S.; Langone, L.; Rolph, T.; Trincardi, F.; Wolff, G.; Gibbs, Z.; Vigliotti, L.; Frignani, M.; van der Post, K.; Branch, N.

    2003-02-01

    A multi-proxy study of a Holocene sediment core (RF 93-30) from the western flank of the central Adriatic, in 77 m of water, reveals a sequence of changes in terrestrial vegetation, terrigenous sediment input and benthic fauna, as well as evidence for variations in sea surface temperature spanning most of the last 7000 yr. The chronology of sedimentation is based on several lines of evidence, including AMS 14C dates of foraminifera extracted from the core, palaeomagnetic secular variation, pollen indicators and dated tephra. The temporal resolution increases towards the surface and, for some of the properties measured, is sub-decadal for the last few centuries. The main changes recorded in vegetation, sedimentation and benthic foraminiferal assemblages appear to be directly related to human activity in the sediment source area, which includes the Po valley and the eastern flanks of the central and northern Appenines. The most striking episodes of deforestation and expanding human impact begin around 3600 BP (Late Bronze Age) and 700 BP (Medieval) and each leads to an acceleration in mass sedimentation and an increase in the proportion of terrigenous material, reflecting the response of surface processes to widespread forest clearance and cultivation. Although human impact appears to be the proximal cause of these changes, climatic effects may also have been important. During these periods, signs of stress are detectable in the benthic foram morphotype assemblages. Between these two periods of increased terrigeneous sedimentation there is smaller peak in sedimentation rate around 2400BP which is not associated with evidence for deforestation, shifts in the balance between terrigenous and authigenic sedimentation, or changes in benthic foraminifera. The mineral magnetic record provides a sensitive indicator of changing sediment sources: during forested periods of reduced terrigenous input it is dominated by authigenic bacterial magnetite, whereas during periods of

  9. Extracellular enzyme activity and dynamics of bacterial community in mucilaginous aggregates of the northern Adriatic Sea.

    PubMed

    Zoppini, Annamaria; Puddu, Alberto; Fazi, Stefano; Rosati, Michela; Sist, Paola

    2005-12-15

    Bacterial degradation of mucilaginous aggregates (creamy layers, stringers and macroflocs) collected during two summer events (2001-2002) was tested. The objective was to describe the temporal trend of the bacterial activity, abundance and composition in the aggregated and dissolved organic matter under different trophic conditions. In the native aggregates proteins and organic phosphorous were actively hydrolyzed as aminopeptidase and alkaline phosphatase activities represented up to 87% and 25% of total activity, respectively; polysaccharides were less hydrolyzed and the highest activities were observed for beta-glucosidase (5% of the total). This hydrolysation pattern tends to a progressive accumulation of long persistent polysaccharides. During short term incubations nutrient addition (P, N and Glucose) differently stimulated bacterial growth in the seawater: P played the main role in stimulating bacterial production from 3 to 6 folds higher than in the control, whereas a secondary C-limitation was observed only for bacteria growing on seawater from macroflocs. This scarce dissolved organic carbon (DOC) bioavailability was confirmed by the lower DOC removal (13% macroflocs, 36% stringers). The total amount of carbon incorporated by bacteria living on aggregates was similar (0.58 mg C L(-1)) both in the control and under P enrichments showing a more balanced condition with respect to the seawater. Hence the well-known P limitation in the Northern Adriatic Sea affects only dissolved organic carbon uptake without influencing the uptake of aggregated organic matter. Organic matter limitation was observed only on stringers--total C incorporated raised to 0.96 mg C L(-1) after PNG addition. Macroflocs release of refractory compounds leads to DOC accumulation (73 microM DOC) contributing to inflate the pool of refractory DOC in the surrounding waters. Several evidences, including different monosaccharide composition of stringers and macroflocs (glucose 15% and 56% on

  10. Influence of seasonal forcing on habitat use by bottlenose dolphins Tursiops truncatus in the Northern Adriatic Sea

    NASA Astrophysics Data System (ADS)

    Bearzi, Giovanni; Azzellino, Arianna; Politi, Elena; Costa, Marina; Bastianini, Mauro

    2008-12-01

    Bottlenose dolphins are the only cetaceans regularly observed in the northern Adriatic Sea, but they survive at low densities and are exposed to significant threats. This study investigates some of the factors that influence habitat use by the animals in a largely homogeneous environment by combining dolphin data with hydrological and physiographical variables sampled from oceanographic ships. Surveys were conducted year-round between 2003 and 2006, totalling 3,397 km of effort. Habitat modelling based on a binary stepwise logistic regression analysis predicted between 81% and 93% of the cells where animals were present. Seven environmental covariates were important predictors: oxygen saturation, water temperature, density anomaly, gradient of density anomaly, turbidity, distance from the nearest coast and bottom depth. The model selected consistent predictors in spring and summer. However, the relationship (inverse or direct) between each predictor and dolphin presence varied among seasons, and different predictors were selected in fall. This suggests that dolphin distribution changed depending on seasonal forcing. As the study area is relatively uniform in terms of bottom topography, habitat use by the animals seems to depend on complex interactions among hydrological variables, caused primarily by seasonal change and likely to determine shifts in prey distribution.

  11. Organochlorine contaminants in tissues of common bottlenose dolphins Tursiops truncatus from the northeastern part of the Adriatic Sea.

    PubMed

    Romanić, S Herceg; Holcer, D; Lazar, B; Klinčić, D; Mackelworth, P; Fortuna, C M

    2014-09-01

    Levels of 24 organochlorine compounds, including toxic mono-ortho PCB congeners, were determined in the organs and tissues (blubber, kidney, lung, muscle, liver, heart) of 13 common bottlenose dolphins (Tursiops truncatus) stranded between 2000 and 2005 in the northern part of the Croatian territorial waters of the Adriatic Sea. Polychlorinated biphenyls (PCBs) were found at higher concentrations in comparison with organochlorine pesticides (OCPs) in all of the analyzed tissues. Sums of six indicator congeners (Σ6PCB) constituted around 50% of the total PCB amount, while PCB-153 and PCB-138 were found to have the highest concentrations. Among the seven investigated OCPs, p,p'-DDE was found at the highest concentrations. In blubber, mean values of 22,048 and 11,310ngg(-1) wet weight were determined for ΣPCB and ΣDDT, respectively. Much lower concentrations were found in muscle samples, followed by similar concentrations in kidneys, liver and heart, while the lowest levels of organochlorine contaminants were found in lungs. The results indicate that p,p'-DDT is still being introduced in the Mediterranean region. PCB concentrations are among the highest found in this region and toxicological assessments indicate that the health of this specie is at high risk.

  12. Trophic status and meiofauna biodiversity in the Northern Adriatic Sea: Insights for the assessment of good environmental status.

    PubMed

    Bianchelli, Silvia; Pusceddu, Antonio; Buschi, Emanuela; Danovaro, Roberto

    2016-02-01

    The Descriptor 5 (Eutrophication) of the EU Marine Strategy Framework Directive aims at preventing the negative effects of eutrophication. However, in coastal systems all indicators based on water column parameters fail in identifying the trophic status and its effects on biodiversity and ecosystem functioning. We investigated benthic trophic status, in terms of sedimentary organic matter quantity, composition and quality, along with meiofaunal abundance, richness of taxa and community composition in three coastal sites (N Adriatic Sea) affected by different levels of anthropogenic stressors. We show that, on the basis of organic matter quantity and composition, the investigated areas can be classified from oligo-to mesotrophic, whereas using meiofauna as a descriptor, their environmental quality ranged from sufficient to moderately impacted. Our results show that the benthic trophic status based on organic matter variables, is not sufficient to provide a sound assessment of the environmental quality in marine coastal ecosystems. However, data reported here indicate that the integration of the meiofaunal variable allows providing robust assessments of the marine environmental status.

  13. Ecological and morphological characteristics of Ephelota gemmipara (Ciliophora, Suctoria), epibiontic on Eudendrium racemosum (Cnidaria, Hydrozoa) from the Adriatic Sea.

    PubMed

    Tazioli, Silvia; Di Camillo, Cristina Gioia

    2013-11-01

    The relationship between the suctorian Ephelota gemmipara and the large hydroid Eudendrium racemosum from the North Adriatic Sea has been studied over its full annual cycle. Ephelota gemmipara settles on the perisarc of the hydroid, usually close to the hydranths in order to exploit the hydroid's food discharges. The life cycle of E. gemmipara is influenced by temperature variations and by its relationship with the host. The hydroid shows an active phase in the summer, and it gets through the adverse winter season forming resting stages. In April, when temperature increases, the hydroid starts its active phase and it is colonized by suctorians. From May to September the suctorians produce multiple buds (swarmers) that detach from the parental cells to settle on an Eudendrium colony. The abundance of the suctorian peaks in September, with more than 1.2 million ind. m(-2). Their proliferation coincides with the maximal abundance of their host and the highest water temperatures. On the contrary, sexual reproduction and the encystment occur when the temperature and the abundance of E. racemosum decrease. Lastly, we also report the presence of symbionts such as bacteria and the parasitic protozoans Tachyblaston ephelotensis and Enigmocoma acinetarum.

  14. Influence of releases of I-129 from reprocessing plants on the marine environment of the North Adriatic Sea.

    PubMed

    Osterc, Andrej; Stibilj, Vekoslava

    2012-03-01

    Compared to the pre-nuclear era, large amounts of (129)I have been released to the marine environment, especially as liquid and gaseous discharges from two European reprocessing plants located at Sellafield and La Hague. Their liquid discharges influence Northern Europe and most research was conducted in the area of the North Atlantic Ocean and the Baltic Sea. In this article data on (129)I content and (129)I/(127)I ratios observed in the North Adriatic Sea, which is a rather enclosed basin of the Mediterranean Sea, are presented. To the best of our knowledge no data on (129)I in the Mediterranean Sea have previously been reported. As this area is isolated from direct liquid discharges, the main transport pathway is probably gaseous releases from reprocessing plants. Surface sea water, the marine alga Fucus virsoides, an iodine accumulator, and the Mediterranean mussel Mytilus galloprovincialis collected in 2009 and 2010, and marine sediment collected in 2005 and 2009 were analysed. The (129)I/(127)I isotopic ratios observed were in the range from 0.8 to 3.0×10(-08) for seawater, from 0.06 to 0.35×10(-08) for marine sediment, from 0.05 to 0.10×10(-08) for F. virsoides and from 0.3 to 0.9×10(-08) for M. galloprovincialis.

  15. Classification of Satellite Derived Chlorophyll a Space-Time Series by Means of Quantile Regression: An Application to the Adriatic Sea

    NASA Astrophysics Data System (ADS)

    Girardi, P.; Pastres, R.; Gaetan, C.; Mangin, A.; Taji, M. A.

    2015-12-01

    In this paper, we present the results of a classification of Adriatic waters, based on spatial time series of remotely sensed Chlorophyll type-a. The study was carried out using a clustering procedure combining quantile smoothing and an agglomerative clustering algorithms. The smoothing function includes a seasonal term, thus allowing one to classify areas according to “similar” seasonal evolution, as well as according to “similar” trends. This methodology, which is here applied for the first time to Ocean Colour data, is more robust with respect to other classical methods, as it does not require any assumption on the probability distribution of the data. This approach was applied to the classification of an eleven year long time series, from January 2002 to December 2012, of monthly values of Chlorophyll type-a concentrations covering the whole Adriatic Sea. The data set was made available by ACRI (http://hermes.acri.fr) in the framework of the Glob-Colour Project (http://www.globcolour.info). Data were obtained by calibrating Ocean Colour data provided by different satellite missions, such as MERIS, SeaWiFS and MODIS. The results clearly show the presence of North-South and West-East gradient in the level of Chlorophyll, which is consistent with literature findings. This analysis could provide a sound basis for the identification of “water bodies” and of Chlorophyll type-a thresholds which define their Good Ecological Status, in terms of trophic level, as required by the implementation of the Marine Strategy Framework Directive. The forthcoming availability of Sentinel-3 OLCI data, in continuity of the previous missions, and with perspective of more than a 15-year monitoring system, offers a real opportunity of expansion of our study as a strong support to the implementation of both the EU Marine Strategy Framework Directive and the UNEP-MAP Ecosystem Approach in the Mediterranean.

  16. Physicochemical signatures of natural surfactant sea films from coastal Middle Adriatic stations

    NASA Astrophysics Data System (ADS)

    Frka, Sanja; Pogorzelski, Stanislaw; Kozarac, Zlatica; Ćosović, Božena

    2013-04-01

    substances of the natural microlayers from coastal Middle Adriatic stations including saline Rogoznica Lake and Krka river estuarine station. Higher primary production during late spring-early autumn is reflected in the presence of microlayers of higher surfactant activity containing on average molecules of lower molecular masses (Mw=0.65±0.27 kDa) and higher miscibility (y=6.46±1.33) and elasticity (E=18.33±2.02 mN/m) modulus in comparison to structural parameters (average Mw=2.15±1.58 kDa; y=3.51±1.46; E=6.41±1.97 mN/m) obtained for microlayers from period of lower organic matter production. Higher inhibition effect on the reduction process of cadmium ions is observed for natural microlayers abundant with SA material from more productive period. This kind of distribution is explained as the consequence of competitive adsorption of hydrophobic lipid-like substances of lower Mw which highly influence the surface structural properties of natural air-water interface forming there segregated surface films during more productive period. This study will offer different perspective on contemporary SML concept taking into account the lipids that act as end-members highly influencing seasonal change of SA concentration and surface structural properties of natural films at the air-water interface.

  17. Benthic fluxes of oxygen, carbon and nutrients in the Marano and Grado Lagoon (northern Adriatic Sea, Italy)

    NASA Astrophysics Data System (ADS)

    De Vittor, C.; Faganeli, J.; Emili, A.; Covelli, S.; Predonzani, S.; Acquavita, A.

    2012-11-01

    Benthic metabolism and carbon and nutrient cycling at the sediment-water interface were studied seasonally in the Marano (sites MB and MC) and Grado Lagoon (sites ART and BAR), northern Adriatic Italy, using porewater vertical profiles and daily fluxes of O2, DIC, DOC, NO3-, NH4+, PO43- and SiO44- measured in situ deployed transparent and dark benthic chambers. Diffusive and benthic fluxes of solutes were evaluated on a seasonal basis. Sites MC and ART were characterized by higher Corg. contents due to input of riverine organic matter and mariculture, respectively. The Corg., Ntot., Ptot., Porg. and Sibiog. contents decreased along the sediment cores while porewater concentrations of DIC, DOC, NO3-, NH4+, PO43- and SiO44- increased along the sediment cores at all study sites due to the degradation of labile sedimentary matter. Higher concentrations of all porewater solutes and higher diffusive fluxes were observed in warmer periods. Benthic fluxes of O2, DIC, NO3-, NH4+, PO43- and SiO44- showed intensive seasonal variations. Based on O2 and DIC metabolism, the lagoon sediments were highly heterotrophic except at BAR being in trophic balance or weakly heterotrophic. NO3- and SiO44- exhibited influxes due to intense microphytobenthic assimilation, mostly by diatoms, and denitrification while extremely low PO43- fluxes suggest P as a limiting factor. The great difference observed between the diffusive and the in situ benthic fluxes suggests the importance of bioturbation and that the pertinent processes occur at the sediment-water interface. Tentative annual budgets of carbon and nutrients in surface sediments of studied sites indicate that their cycling, compared to burial flux, is more intensive at the sediment-water interface. These basic benthic biogeochemical processes can be important to better understand the trace metal cycling, especially Hg mobilization and sequestration, in the lagoon environment.

  18. Parametric bleaching of dense plasmas

    NASA Astrophysics Data System (ADS)

    Gradov, O. M.; Ramazashvili, R. R.

    1981-11-01

    A mechanism is proposed for the nonlinear bleaching of a dense plasma slab. In this new mechanism, the electromagnetic wave incident on the plasma decays into plasma waves and then reappears as a result of the coalescence of the plasma waves at the second boundary of the slab.

  19. Burried MIS 5 abrasion platforms in the Bay of Koper (Gulf of Trieste, Northern Adriatic) confirm long-term subsidence of the Northern Adriatic region

    NASA Astrophysics Data System (ADS)

    Trobec, Ana; Šmuc, Andrej; Poglajen, Sašo; Vrabec, Marko

    2016-04-01

    The youngest seafloor sediments of the Gulf of Trieste (Northern Adriatic) are represented by an up to several 100 meters thick succession of Pliocene to Quaternary continental and shallow-marine deposits recording numerous transgressive-regressive cycles. These sediments are separated from older lithologies (mainly Eocene flysch) by an erosional unconformity. Previous geophysical campaigns conducted in the Italian part of the Gulf of Trieste revealed a complex undulating morphology of the unconformity characterised by numerous morphological steps in the flysch appearing between 40 and 200 m below sea level. From correlation with onshore well data from the Friuli and Veneto area it is assumed that the highest system of these unconformities located at approximately 40 mbsl represents a marine abrasion platform formed during the MIS 5 period sea-level highstand. We present the first observations of these abrasion platforms in the Bay of Koper in the southern (Slovenian) part of the Gulf of Trieste. A series of perpendicular sub-bottom sonar profiles with a spacing of 250-500 meters was acquired in the Bay of Koper between 2009 and 2012 with the Innomar parametric sediment echo sounder SES-2000. Along the northern coast of the bay several acoustic facies were resolved, including the top erosional unconformity surface of the flysch. On this surface we located platforms at 35 ms (platform A), 40 ms (platform B) and 50 ms (platform C) of two-way-travel time. The top of abrasion platform B coincides with the top of a sediment progradational wedge which overlies abrasion platform C. No progradational wedge is developed at the top of platform A. Due to signal attenuation and multiples sub-bottom profiles could not be interpreted below 53 ms TWT time. We used a sound velocity of 1650 m/s for the time to depth conversion, which places the platforms at the depth of 28, 33 and 41 mbsl, respectively. Assuming that the abrasion platforms are a remnant of the MIS 5 highstand, this

  20. Oil spill model coupled to an ultra-high-resolution circulation model: implementation for the Adriatic Sea

    NASA Astrophysics Data System (ADS)

    Korotenko, K.

    2003-04-01

    An ultra-high-resolution version of DieCAST was adjusted for the Adriatic Sea and coupled with an oil spill model. Hydrodynamic module was developed on base of th low dissipative, four-order-accuracy version DieCAST with the resolution of ~2km. The oil spill model was developed on base of particle tracking technique The effect of evaporation is modeled with an original method developed on the base of the pseudo-component approach. A special dialog interface of this hybrid system allowing direct coupling to meteorlogical data collection systems or/and meteorological models. Experiments with hypothetic oil spill are analyzed for the Northern Adriatic Sea. Results (animations) of mesoscale circulation and oil slick modeling are presented at wabsite http://thayer.dartmouth.edu/~cushman/adriatic/movies/

  1. Warm Dense Matter: An Overview

    SciTech Connect

    Kalantar, D H; Lee, R W; Molitoris, J D

    2004-04-21

    This document provides a summary of the ''LLNL Workshop on Extreme States of Materials: Warm Dense Matter to NIF'' which was held on 20, 21, and 22 February 2002 at the Wente Conference Center in Livermore, CA. The warm dense matter regime, the transitional phase space region between cold material and hot plasma, is presently poorly understood. The drive to understand the nature of matter in this regime is sparking scientific activity worldwide. In addition to pure scientific interest, finite temperature dense matter occurs in the regimes of interest to the SSMP (Stockpile Stewardship Materials Program). So that obtaining a better understanding of WDM is important to performing effective experiments at, e.g., NIF, a primary mission of LLNL. At this workshop we examined current experimental and theoretical work performed at, and in conjunction with, LLNL to focus future activities and define our role in this rapidly emerging research area. On the experimental front LLNL plays a leading role in three of the five relevant areas and has the opportunity to become a major player in the other two. Discussion at the workshop indicated that the path forward for the experimental efforts at LLNL were two fold: First, we are doing reasonable baseline work at SPLs, HE, and High Energy Lasers with more effort encouraged. Second, we need to plan effectively for the next evolution in large scale facilities, both laser (NIF) and Light/Beam sources (LCLS/TESLA and GSI) Theoretically, LLNL has major research advantages in areas as diverse as the thermochemical approach to warm dense matter equations of state to first principles molecular dynamics simulations. However, it was clear that there is much work to be done theoretically to understand warm dense matter. Further, there is a need for a close collaboration between the generation of verifiable experimental data that can provide benchmarks of both the experimental techniques and the theoretical capabilities. The conclusion of this

  2. An algorithm for the detection of the white-tide ('mucilage') phenomenon in the Adriatic Sea using AVHRR data

    SciTech Connect

    Tassan, S. )

    1993-06-01

    An algorithm using AVHRR data has been set up for the detection of a white tide consisting of algae secretion ('mucilage'), an event occurring in the Adriatic Sea under particular meteorological conditions. The algorithm, which includes an ad hoc procedure for cloud masking, has been tested with reference to the mucilage map obtained from the analysis of contemporary Thematic Mapper data, as well as by comparing consecutive AVHRR scenes. The main features of the exceptional mucilage phenomenon that took place in the northern basin of the Adriatic Sea in summer 1989 are shown by a time series of maps.

  3. Boundary Preserving Dense Local Regions.

    PubMed

    Kim, Jaechul; Grauman, Kristen

    2015-05-01

    We propose a dense local region detector to extract features suitable for image matching and object recognition tasks. Whereas traditional local interest operators rely on repeatable structures that often cross object boundaries (e.g., corners, scale-space blobs), our sampling strategy is driven by segmentation, and thus preserves object boundaries and shape. At the same time, whereas existing region-based representations are sensitive to segmentation parameters and object deformations, our novel approach to robustly sample dense sites and determine their connectivity offers better repeatability. In extensive experiments, we find that the proposed region detector provides significantly better repeatability and localization accuracy for object matching compared to an array of existing feature detectors. In addition, we show our regions lead to excellent results on two benchmark tasks that require good feature matching: weakly supervised foreground discovery and nearest neighbor-based object recognition.

  4. Radiative properties of dense nanofluids.

    PubMed

    Wei, Wei; Fedorov, Andrei G; Luo, Zhongyang; Ni, Mingjiang

    2012-09-01

    The radiative properties of dense nanofluids are investigated. For nanofluids, scattering and absorbing of electromagnetic waves by nanoparticles, as well as light absorption by the matrix/fluid in which the nanoparticles are suspended, should be considered. We compare five models for predicting apparent radiative properties of nanoparticulate media and evaluate their applicability. Using spectral absorption and scattering coefficients predicted by different models, we compute the apparent transmittance of a nanofluid layer, including multiple reflecting interfaces bounding the layer, and compare the model predictions with experimental results from the literature. Finally, we propose a new method to calculate the spectral radiative properties of dense nanofluids that shows quantitatively good agreement with the experimental results.

  5. Measurements of storm and nonstorm circulation in the northern Adriatic: October 2002 Through April 2003

    USGS Publications Warehouse

    Book, J.W.; Signell, R.P.; Perkins, H.

    2007-01-01

    Fifteen bottom-mounted Acoustic Doppler Current Profilers were deployed from October 2002 through April 2003 in the northern Adriatic Sea. Average transport from the portion of the Western Adriatic Current (WAC) along the Italian slope was 0.1470 ?? 0.0043 Sv, punctuated by bursts of more than twice that amount during storm events. Monthly means were calculated with times of strong wind-driven circulation excluded. These suggest a 2002/2003 seasonal separation consisting of October, December through February, and March through April. An extreme Po River flood influenced November conditions making seasonal categorization difficult. October generally had more kinetic energy and more vertical structure than other months, and near-inertial waves were more frequent in April and October. The Eastern Adriatic Current (EAC)/WAC (i.e. inflow/outflow) system was clearly present in the means for all months. The cyclonic gyre north of the Po River was present October through February. Generally, in the WAC, over 50% of kinetic energy came from vertically uniform monthly mean flows. Elsewhere, eddy kinetic energy was stronger than mean kinetic energy with 10-40% contributions for vertically uniform monthly mean flows, 40-60% for vertically uniform monthly varying flows, and 10-30% for vertically varying monthly varying flows. Mean currents for bora storms indicate enhancement of the EAC/WAC and the cyclonic northern gyre, a shift toward Kvarner Bay in EAC direction, a circulation null point south of the Po, and double-gyre bifurcation of flow at Istria. Strengthening of both the EAC and WAC also occurs during sirocco storms. Copyright 2007 by the American Geophysical Union.

  6. The Adriatic Sea ecosystem seasonal cycle: Validation of a three-dimensional numerical model

    NASA Astrophysics Data System (ADS)

    Polimene, L.; Pinardi, N.; Zavatarelli, M.; Colella, S.

    2006-03-01

    A three-dimensional coupled biogeochemical-circulation numerical model was implemented in the Adriatic Sea. The biogeochemical part of the model is a development of the European Seas Regional Ecosystem Model (ERSEM II), while the circulation model is the Adriatic Sea implementation of the Princeton Ocean Model (POM). The model was run under climatological monthly varying atmospheric and river runoff forcing in order to reproduce seasonal circulation and biochemical processes. Simulated chlorophyll, nutrient, and plankton biomass and distributions were analyzed and compared with the data coming from a historic in situ data set and a newly constructed chlorophyll climatological data set from SeaWiFS. Model reproduction of the chlorophyll seasonal cycle is, at least qualitatively, in good agreement both with the remote sensing and the in situ data. However, larger production than observed is simulated during the late winter and spring, probably due to inadequate knowledge of the nutrient inputs. Comparison between simulated nutrients and observations shows a general underestimation for orthophosphate and orthosilicate, while nitrate is mostly overestimated. The shape of the nutrient-simulated profiles is in qualitatively good agreement with observations in the central and southern part of the basin. The analysis of the ratio between the large (>20 μm) and small (<20 μm) phytoplankton biomass and between the bacteria and phytoplankton biomass shows that the Western Adriatic Coastal Current is not only a physical frontal structure but also an ecosystem front, where larger phytoplankton grow on the coastal side while smaller ones are present offshore where the microbial loop is the dominant food web.

  7. Role of Recruitment Processes in Structuring Coralligenous Benthic Assemblages in the Northern Adriatic Continental Shelf.

    PubMed

    Fava, Federica; Ponti, Massimo; Abbiati, Marco

    2016-01-01

    Coralligenous biogenic reefs are among the most diverse marine habitats in the Mediterranean Sea. The northern Adriatic mesophotic coralligenous outcrops host very rich and diverse epibenthic assemblages. Several studies quantified the low temporal variability and high spatial heterogeneity of these habitats, while processes driving structuring and differentiation are still poorly understood. To shed light on these processes, temporal and spatial patterns of colonisation were investigated using travertine tiles deployed on three coralligenous outcrops, corresponding to the main typologies of benthic assemblages described in previous studies. Three years after deployment, assemblages colonising travertine tiles resembled the differentiation among sites revealed by the natural assemblages in terms of major ecological groups. Processes structuring and maintaining species diversity have been explored. Pioneer species with high reproduction rate, long distance larval dispersal and fast growth (e.g. the serpulid polychaete Spirobranchus triqueter and the bivalve Anomia ephippium), were the most abundant in the early stages of recruitment on the two outcrops further away from the coast and with lower sedimentation. Their success may vary according to larval availability and environmental conditions (e.g., sedimentation rates). At these sites early-stage lasted 10-12 months, during which even species from natural substrates began colonising tiles by settlement of planktonic propagules (e.g., encrusting calcareous Rhodophyta) and lateral encroachment (e.g., sponges and ascidians). On coastal outcrop, exposed to a higher sedimentation rates, tiles were colonised by fast-growing algal turfs. Resilience of northern Adriatic coralligenous assemblages, and maintenance of their diversity, appeared largely entrusted to asexual reproduction. Exploring the mechanisms that underlie the formation and maintenance of the species diversity is crucial to improve our understanding of

  8. Role of Recruitment Processes in Structuring Coralligenous Benthic Assemblages in the Northern Adriatic Continental Shelf

    PubMed Central

    Abbiati, Marco

    2016-01-01

    Coralligenous biogenic reefs are among the most diverse marine habitats in the Mediterranean Sea. The northern Adriatic mesophotic coralligenous outcrops host very rich and diverse epibenthic assemblages. Several studies quantified the low temporal variability and high spatial heterogeneity of these habitats, while processes driving structuring and differentiation are still poorly understood. To shed light on these processes, temporal and spatial patterns of colonisation were investigated using travertine tiles deployed on three coralligenous outcrops, corresponding to the main typologies of benthic assemblages described in previous studies. Three years after deployment, assemblages colonising travertine tiles resembled the differentiation among sites revealed by the natural assemblages in terms of major ecological groups. Processes structuring and maintaining species diversity have been explored. Pioneer species with high reproduction rate, long distance larval dispersal and fast growth (e.g. the serpulid polychaete Spirobranchus triqueter and the bivalve Anomia ephippium), were the most abundant in the early stages of recruitment on the two outcrops further away from the coast and with lower sedimentation. Their success may vary according to larval availability and environmental conditions (e.g., sedimentation rates). At these sites early-stage lasted 10–12 months, during which even species from natural substrates began colonising tiles by settlement of planktonic propagules (e.g., encrusting calcareous Rhodophyta) and lateral encroachment (e.g., sponges and ascidians). On coastal outcrop, exposed to a higher sedimentation rates, tiles were colonised by fast-growing algal turfs. Resilience of northern Adriatic coralligenous assemblages, and maintenance of their diversity, appeared largely entrusted to asexual reproduction. Exploring the mechanisms that underlie the formation and maintenance of the species diversity is crucial to improve our understanding of

  9. Application of a Dense Gas Technique for Sterilizing Soft Biomaterials

    PubMed Central

    Karajanagi, Sandeep S.; Yoganathan, Roshan; Mammucari, Raffaella; Park, Hyoungshin; Cox, Julian; Zeitels, Steven M.; Langer, Robert; Foster, Neil R.

    2017-01-01

    Sterilization of soft biomaterials such as hydrogels is challenging because existing methods such as gamma irradiation, steam sterilization, or ethylene oxide sterilization, while effective at achieving high sterility assurance levels (SAL), may compromise their physicochemical properties and biocompatibility. New methods that effectively sterilize soft biomaterials without compromising their properties are therefore required. In this report, a dense-carbon dioxide (CO2)-based technique was used to sterilize soft polyethylene glycol (PEG)-based hydrogels while retaining their structure and physicochemical properties. Conventional sterilization methods such as gamma irradiation and steam sterilization severely compromised the structure of the hydrogels. PEG hydrogels with high water content and low elastic shear modulus (a measure of stiffness) were deliberately inoculated with bacteria and spores and then subjected to dense CO2. The dense CO2-based methods effectively sterilized the hydrogels achieving a SAL of 10−7 without compromising the viscoelastic properties, pH, water-content, and structure of the gels. Furthermore, dense CO2-treated gels were biocompatible and non-toxic when implanted subcutaneously in ferrets. The application of novel dense CO2-based methods to sterilize soft biomaterials has implications in developing safe sterilization methods for soft biomedical implants such as dermal fillers and viscosupplements. PMID:21337339

  10. Investigation of the loss of byssus in Mytilus galloprovincialis from mussel farms in the Adriatic Sea.

    PubMed

    Franchini, Antonella; Malagoli, Davide; Ottaviani, Enzo

    2005-10-01

    A fungal infection has been found in the mussel Mytilus galloprovincialis from Adriatic Sea mussel farms. The infection ultimately results in the loss of the byssus, with serious consequences for mussel farming yield. The pathogen provokes the progressive destruction of the foot muscles, also damaging related structures such as the intra-organism part of the byssus apparatus, resulting in loss of the thread component. The affected health status of the animal is also sustained by modifications in the digestive gland structure, ranging from hyperactivity to extreme cell death in the tubula. At present, the identity of the harmful fungus is unknown.

  11. Dimorphic growth in male and female cuttlefish Sepia orbignyana (Cephalopoda: Sepiidae) from the Adriatic Sea

    NASA Astrophysics Data System (ADS)

    Bello, Giambattista

    2001-07-01

    The relationships between mantle length and number of cuttlebone chambers (or septa), and between weight and number of cuttlebone chambers were studied in Sepia orbignyana collected in the south-western Adriatic Sea. Weight-at-chamber count and mantle length-at-chamber count were statistically higher in females than in males. As the available literature suggests that the rate of cuttlebone septum formation is the same in both sexes of Sepia species, it follows that in S. orbignyana females have higher growth rates than males.

  12. Measurements of Storm and Nonstorm Circulation in the Northern Adriatic: October 2002 Through April 2003

    DTIC Science & Technology

    2007-11-16

    dcgrecs inc. 9 of 20 CIIS92 BOOK El AL.: ADRIATIC CIRCULATION C11S92 in the inertial oscillation energy band (as indicated by the clockwise rotary...0.3 in January through in this frequency band . The percentages are especially high March. and peaks to 1.8 for April. In April the median for all...the presence of ncar-inertial waves. The sites SS2, VRI. and VR2 in March and April, spatial contribution of oscillations from this frequency band was

  13. Coupled Ocean-Atmosphere Nested Modeling of the Adriatic Sea During Winter and Spring 2001

    DTIC Science & Technology

    2003-10-15

    offshore of Zadar . The 36-km COAMPS mean wind stress fails to resolve the bora fingers situated over the Gulf of Trieste and off Zadar . Where the bora blows...Adriatic. However, in the Gulf of Trieste and offshore of Zadar , fluctuating and mean wind stress values are stronger in the 4-km-resolution model. Also...the northern portion of the Gulf of Trieste, off the southern tip of the Istrian peninsula, and north of the Croatian town of Zadar . By contrast, the

  14. Genetic identification of a rare record of Ommastrephes Bartramii (Cephalopoda: Ommastrephidae) from the Eastern Adriatic Sea.

    PubMed

    Franjević, Damjan; Skaramuca, Daria; Katavić, Vedran; Rajević, Nives; Skaramuca, Boško

    2015-01-01

    The neon flying squid Ommastrephes bartramii Lesueur, 1821 belongs to the Ommastrephidae, Cephalopoda family. The family Ommastrephidae (Mollusca: Cephalopoda) includes many commercially important species, dispersed around the world. The Ommastrephidae family is conventionally divided into three subfamilies (Illicinae, Todarodinae, and Ommastrephinae). We report a specimen of neon flying squid caught in the winter 2013 at Luka Šipanska, Island of Šipan, Croatia and identified at the genetic level using the standard mitochondrial COI barcode region. This record represents the first genetic identification of a neon flying squid from the Adriatic Sea.

  15. Constructing Dense Graphs with Unique Hamiltonian Cycles

    ERIC Educational Resources Information Center

    Lynch, Mark A. M.

    2012-01-01

    It is not difficult to construct dense graphs containing Hamiltonian cycles, but it is difficult to generate dense graphs that are guaranteed to contain a unique Hamiltonian cycle. This article presents an algorithm for generating arbitrarily large simple graphs containing "unique" Hamiltonian cycles. These graphs can be turned into dense graphs…

  16. Anthropogenic disturbance and spatial heterogeneity of macrobenthic invertebrate assemblages in coastal lagoons: the study case of Pialassa Baiona (northern Adriatic Sea)

    NASA Astrophysics Data System (ADS)

    Ponti, Massimo; Casselli, Chiara; Abbiati, Marco

    2011-03-01

    The distribution patterns of macrobenthic invertebrate assemblages at different spatial scales and in relation to natural and anthropogenic disturbance gradients were investigated in the Pialassa Baiona, a eutrophic and polluted brackish coastal lagoon located along the Italian coast of the northern Adriatic Sea. This coastal lagoon shows a complex physiography with several shallow water ponds and channels separated by discontinuous artificial embankments. Environmental variables and macrobenthic invertebrate assemblages showed higher heterogeneity at small spatial scale (i.e. within channels and ponds). Distinction between channels and ponds is only weakly supported by the distribution patterns of macrobenthic assemblages. Depth was the major factor in structuring benthic communities within ponds, while species distributions along the channels were strongly correlated with the anthropogenic disturbance gradient. Anthropogenic disturbance mainly affected species richness, which was inversely correlated with the organic carbon contents in the sediments and the water surface temperature, which is affected by the input of cooling water from two thermal power plants. Some opportunistic species, like the polychaetes Streblospio shrubsolii and Capitella capitata, were more abundant in the southern polluted areas. In particular, the abundance of S. shrubsolii significantly increased with organic carbon contents in the sediments and water surface temperature, while C. capitata was more abundant in the warmed sites and close to sewages. Conversely, the abundance of the amphipod Corophium insidiosum was inversely related to organic carbon contents.

  17. Impacts of maintenance channel dredging in a northern Adriatic coastal lagoon. II: Effects on macrobenthic assemblages in channels and ponds

    NASA Astrophysics Data System (ADS)

    Ponti, Massimo; Pasteris, Andrea; Guerra, Roberta; Abbiati, Marco

    2009-10-01

    Coastal lagoons are ephemeral habitats whose conservation requires human intervention, such as maintenance dredging of inner channels. Dredging can reduce the abundance of benthic species due to the removal of individuals with the sediment, modify sediment properties, and resuspend fine sediment, nutrients and pollutants, which can lead to eutrophication, hypoxic events and increasing toxicity. Both direct effects in the dredged channel and possible indirect effects in surrounding shallow areas could be expected. This study assesses the effects of the channel maintenance dredging, performed between October 2004 and August 2005, on the invertebrate assemblages both in channels and adjacent ponds in the northern Adriatic coastal lagoon of Pialassa Baiona. The lagoon is affected by eutrophication, chemical and thermal pollution from wastewater treatment and power plants. Three impacted sites were located in the dredged channel and three in the adjacent interconnected shallow water ponds, while three non-impacted sites were located in a channel and in a pond far from the dredged area. Replicate samples were collected from each site one time before and one time after the dredging operations. Despite the extent of the intervention, effects of the dredging on macrobenthic assemblages were detected only within the dredged channel, while in the surrounding ponds no clear and unequivocal effects were found. In particular the dredging could have promoted the increase of the abundance of the polychaete Streblospio shrubsolii in the southern and central parts of the dredged channel and the increase in abundance of the amphipod Corophium insidiosum in the northern side, compared to the controls. Instead, species diversity was reduced in the central and northern parts of the dredged channel. These effects on the macrobenthic invertebrate assemblages could be related to the observed changes of sediment characteristics, contamination and toxicity. Overall, direct effects on benthic

  18. Levels of polychlorinated biphenyls and organochlorine pesticides in some edible marine organisms from the Central Adriatic Sea.

    PubMed

    Perugini, M; Cavaliere, M; Giammarino, A; Mazzone, P; Olivieri, V; Amorena, M

    2004-11-01

    Concentrations of polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCs) were found in tissue of marine organisms such as Mediterranean mussel, Norway lobster, red mullet, common cuttle-fish, European flying squid, European anchovy, European pilchard and Atlantic mackerel, coming from two sites along the Abruzzo coast of the Adriatic Sea. Species were selected due to their habitat, trophic level, feeding behaviour and their use in the Italian diet. Mussels, filter feeder and sedentary organisms, were used in order to test water pollution whereas Norway lobster and red mullet (benthic fish) were used in order to test sediment pollution. The concentration of ?PCBs exceeded that of ?OCs in the samples analysed. The highest concentrations of ?PCBs (1415 ng/g lipid weight) and ?OCs (507 ng/g lipid weight) were found in pilchard while the lowest concentrations of the same pollutants were found in cephalopods. Our results have shown that species such as anchovy, pilchard and mackerel, were the most polluted due to their location at the last level of the trophic chain. All samples contained different concentrations of PCBs and among these, congeners 153 and 138 were the most representative. Among the OCs, except for the cuttle-fish, the highest concentrations were found for p,p(')-DDE and p,p(')-DDD that are metabolite of DDT. The prevailing DDE presence, compared to DDT (high DDE/DDT ratio), suggested that the biotransformation rate of pollutants was very efficacious in fish and above all in crustaceans. Results have also been interpreted in terms of geographical distribution and organisms' biological cycle. None of the samples analysed exceeded the tolerance limits established by the OCs Italian legislation.

  19. Recent changes in the marine ecosystems of the northern Adriatic Sea

    NASA Astrophysics Data System (ADS)

    Giani, Michele; Djakovac, Tamara; Degobbis, Danilo; Cozzi, Stefano; Solidoro, Cosimo; Umani, Serena Fonda

    2012-12-01

    This review of studies on long term series on river discharges, oceanographic features, plankton, fish and benthic compartments, collected since the 1970s revealed significant changes of mechanisms and trophic structures in the northern Adriatic ecosystems. A gradual increase of eutrophication pressure occurred during the 1970s until the mid 1980s, followed by a reversal of the trend, particularly marked in the 2000s. This trend was ascribed to the combination of a reduction of the anthropogenic impact, mainly due to a substantial decrease of the phosphorus loads, and of climatic modifications, resulting in a decline of atmospheric precipitations and, consequently, of the runoff in the northern Adriatic Sea. Significant decreases of the phytoplankton abundances were observed after the mid 1980s, concurrently with changes in the species composition of the communities, with an evident shift toward smaller cells or organism sizes. Moreover, changes in the zooplankton community were also observed. A decrease of demersal fishes, top predators and small pelagic fishes was ascribed to both overfishing and a demise of eutrophication. Macrozoobenthic communities slowly recovered in the last two decades after the anoxia events of the 1970s and 1980s. An increasing number of non-autochthonous species has been recorded in the last decades moreover the increasing seawater temperature facilitated the spreading of thermophilic species.

  20. Northern Adriatic meteorological tsunamis: Assessment of their potential through ocean modeling experiments

    NASA Astrophysics Data System (ADS)

    Å epić, Jadranka; Vilibić, Ivica; Fine, Isaac

    2015-04-01

    Potential for generation of meteotsunami waves via open ocean resonance has been documented for the shallow northern Adriatic, based on a set of barotropic numerical modeling experiments. Model simulations were forced by a bell-shaped traveling atmospheric (air pressure, wind) disturbance, with shape and propagation parameters chosen in accordance with measurements done during several observed northern Adriatic meteotsunamis. Air pressure disturbances were found to generate much larger meteotsunami waves than wind disturbances, with wind disturbances having a limited influence in the very coastal and shallow areas only. Numerical simulations reveal that the most important factor for generation of large meteotsunami waves is matching between the speed of the atmospheric disturbance and the speed of long-ocean waves. Already a small (˜10%) deviation from resonant conditions stops the wave growth and dramatically decreases height of predicted waves. A train of atmospheric disturbances can significantly increase maximum wave heights at selected locations at which multiple reflections and superimpositions of meteotsunami waves occur. Sensitivity of model simulations to resonant conditions and limited cross-propagation width of atmospheric disturbance explain the localization of destructive meteotsunami waves in a limited area during destructive historic events. Mapping of maximum predicted wave heights indicates places with large meteotsunami hazard potential, matching the locations where real events were observed, and may be a useful tool for assessing vulnerability and risks in coastal areas during extreme sea level events.

  1. Survey of Anisakis sp. and Hysterothylacium sp. in sardines and anchovies from the North Adriatic Sea.

    PubMed

    Cavallero, S; Magnabosco, C; Civettini, M; Boffo, L; Mingarelli, G; Buratti, P; Giovanardi, O; Fortuna, C M; Arcangeli, G

    2015-05-04

    The occurrence of larval Anisakidae and Raphidascarididae in anchovies and sardines from the North Adriatic Sea has been estimated. Anisakis pegreffii and Hysterothylacium aduncum were reported, with low prevalence values. In brief, a total amount of 7650 fish specimens collected between September 2011 and 2012 were analysed using three different inspection analyses: a visual inspection of the coelomic cavity, an examination of the viscera exploiting the positive hydro-tropism of the larvae (modified Baermann technique) and enzymatic digestion of muscular tissue pools. Low level of infestation was reported for Anisakis sp. in both in anchovies and sardines, while higher values were reported for Hysterothylacium sp. Subsamples of nematodes collected were characterized at species level using the molecular diagnostic key based on ITS nuclear ribosomal region, and A. pegreffii and H. aduncum were identified. The low prevalence of Anisakis sp. in sardines and anchovies from the North Adriatic Sea could be related to the peculiar distribution of cetaceans and carnivorous zooplankton in the investigated region and could be used as a potential tag to define oily fishes from this specific fishing area as at low-risk for anisakiasis.

  2. Ingestion of marine debris by loggerhead sea turtles, Caretta caretta, in the Adriatic Sea.

    PubMed

    Lazar, Bojan; Gračan, Romana

    2011-01-01

    We examined the occurrence of marine debris in the gastrointestinal tract of 54 loggerhead sea turtles (Caretta caretta) found stranded or incidentally captured dead by fisheries in the Adriatic Sea, with a curved carapace length of 25.0-79.2 cm. Marine debris was present in 35.2% of turtles and included soft plastic, ropes, Styrofoam and monofilament lines found in 68.4%, 42.1%, 15.8% and 5.3% of loggerheads that have ingested debris, respectively. The dry mass of debris per turtle was low, ranging from <0.01 to 0.71 g, and the ingestion was not significantly affected by sex or body size (all p>0.05). Marine debris averaged 2.2 ± 8.0% of dry mass of gut content, with a maximum of 35% found in a juvenile turtle that most likely died due to debris ingestion. Considering the relatively high occurrence of debris intake and possible sub-lethal effects of even small quantities of marine debris, this can be an additional factor of concern for loggerheads in the Adriatic Sea.

  3. First evaluation of the threat posed by antifouling biocides in the Southern Adriatic Sea.

    PubMed

    Manzo, Sonia; Ansanelli, Giuliana; Parrella, Luisa; Di Landa, Giuseppe; Massanisso, Paolo; Schiavo, Simona; Minopoli, Carmine; Lanza, Bruno; Boggia, Raffaella; Aleksi, Pellumb; Tabaku, Afrim

    2014-08-01

    The CARISMA project (characterization and ecological risk analysis of antifouling biocides in the Southern Adriatic Sea) aims to appraise the quality of the Southern Adriatic Sea between Italy (Apulia region) and Albania and, in particular, the impact due to the use of biocidal antifouling coatings. Under this project, a preliminary survey at the main hot spots of contamination (e.g. ports and marinas) was conducted at the end of the nautical season in 2012. Chemical seawater analyses were complemented with ecotoxicological assays and the results were analyzed by principal component analysis (PCA). As expected, PCA splits the Albanian and Italian ports, according to the different degrees of contamination indicated for the two countries by the experimental data, highlighting the most critical situation in one port of Apulia. In addition, in order to assess the potential adverse ecological effects posed by antifouling agents (i.e. tributyltin (TBT)-irgarol-diuron) on non-target marine organisms, hazard quotients (HQ) were calculated. The results showed a low risk posed by irgarol and diuron whereas the probability of adverse effects was high in the case of TBT.

  4. Trichoptera biodiversity of the Aegean and Adriatic sea basins in the republic of Kosovo.

    PubMed

    Ibrahimi, Halil; Kučinić, Mladen; Gashi, Agim; Grapci-Kotori, Linda

    2014-01-01

    We present the first preliminary inventory of Trichoptera taxa in the Aegean and Adriatic Sea basins in Kosovo that have previously received poor and fragmentary attention. Adult caddisflies were collected using ultraviolet (UV) light traps in 13 stations in areas of the Aegean Sea and Adriatic Sea drainage basins in Kosovo. Nineteen species out of 82, reported in this article, are first records for the Kosovo caddisfly fauna. Five genera are recorded for the first time in Kosovo: Brachycentrus, Ecclisopteryx, Psilopteryx, Thremma, and Oecetis. During this investigation, we found several Southeastern European endemic and rare species whose previous known distribution was limited to particular areas of this region, as well as other species whose distribution is considerably enlarged by this investigation: Polycentropus ierapetra, Polycentropus irroratus, Chaetopteryx stankovici, Drusus schmidi, Drusus tenellus, Potamophylax goulandriourum, Oecetis notata, and Notidobia melanoptera. Even though this article is a result of a limited sampling effort, it increases the number of Trichoptera taxa recorded for the Republic of Kosovo to 131.

  5. Bacterial diversity of polluted surface sediments in the northern Adriatic Sea.

    PubMed

    Korlević, Marino; Zucko, Jurica; Dragić, Mirjana Najdek; Blažina, Maria; Pustijanac, Emina; Zeljko, Tanja Vojvoda; Gacesa, Ranko; Baranasic, Damir; Starcevic, Antonio; Diminic, Janko; Long, Paul F; Cullum, John; Hranueli, Daslav; Orlić, Sandi

    2015-05-01

    Samples were collected from sea sediments at seven sites in the northern Adriatic Sea that included six sites next to industrial complexes and one from a tourist site (recreational beach). The samples were assayed for alkanes and polycyclic aromatic hydrocarbons. The composition of the hydrocarbon samples suggested that industrial pollution was present in most cases. A sample from one site was also grown aerobically under crude oil enrichment in order to evaluate the response of indigenous bacterial populations to crude oil exposure. Analysis of 16S rRNA gene sequences showed varying microbial biodiversity depending on the level of pollution--ranging from low (200 detected genera) to high (1000+ genera) biodiversity, with lowest biodiversity observed in polluted samples. This indicated that there was considerable biodiversity in all sediment samples but it was severely restricted after exposure to crude oil selection pressure. Phylogenetic analysis of putative alkB genes showed high evolutionary diversity of the enzymes in the samples and suggested great potential for bioremediation and bioprospecting. The first systematic analysis of bacterial communities from sediments of the northern Adriatic Sea is presented, and it will provide a baseline assessment that may serve as a reference point for ecosystem changes and hydrocarbon degrading potential--a potential that could soon gain importance due to plans for oil exploitation in the area.

  6. PSP toxins profile in ascidian Microcosmus vulgaris (Heller, 1877) after human poisoning in Croatia (Adriatic Sea).

    PubMed

    Roje-Busatto, Romana; Ujević, Ivana

    2014-03-01

    Toxins known to cause Paralytic Shellfish Poisoning (PSP) syndrome in humans that can have serious economic consequences for aquaculture were determined in ascidians of the genus Microcosmus. Significant concentrations of toxins were confirmed in all tested samples collected from the western coast of Istria Peninsula (Adriatic Sea, Croatia) when six people were poisoned following the consumption of fresh ascidians. Several species of bivalves that were under continuous monitoring had not accumulated PSP toxins although they were exposed to the same environmental conditions over the survey period. In the present study, HPLC-FLD with pre-column oxidation of PSP toxins has been carried out to provide evidence for the first human intoxication due to consumption of PSP toxic ascidians (Microcosmus vulgaris, Heller, 1877) harvested from the Adriatic Sea. Qualitative analysis established the presence of six PSP toxins: saxitoxin (STX), decarbamoylsaxitoxin (dcSTX), gonyautoxins 2 and 3 (GTX2,3), decarbamoylgonyautoxins 2 and 3 (dcGTX2,3), gonyautoxin 5 (GTX5) and N-sulfocarbamoylgonyautoxins 1 and 2 (C1,2), while quantitative analysis suggested STX and GTX2,3 as dominant toxin types and the ones that contribute the most to the overall toxicity of these samples with concentrations near the regulatory limit.

  7. Probing Cold Dense Nuclear Matter

    SciTech Connect

    Subedi, Ramesh; Shneor, R.; Monaghan, Peter; Anderson, Bryon; Aniol, Konrad; Annand, John; Arrington, John; Benaoum, Hachemi; Benmokhtar, Fatiha; Bertozzi, William; Boeglin, Werner; Chen, Jian-Ping; Choi, Seonho; Cisbani, Evaristo; Craver, Brandon; Frullani, Salvatore; Garibaldi, Franco; Gilad, Shalev; Gilman, Ronald; Glamazdin, Oleksandr; Hansen, Jens-Ole; Higinbotham, Douglas; Holmstrom, Timothy; Ibrahim, Hassan; Igarashi, Ryuichi; De Jager, Cornelis; Jans, Eddy; Jiang, Xiaodong; Kaufman, Lisa; Kelleher, Aidan; Kolarkar, Ameya; Kumbartzki, Gerfried; LeRose, John; Lindgren, Richard; Liyanage, Nilanga; Margaziotis, Demetrius; Markowitz, Pete; Marrone, Stefano; Mazouz, Malek; Meekins, David; Michaels, Robert; Moffit, Bryan; Perdrisat, Charles; Piasetzky, Eliazer; Potokar, Milan; Punjabi, Vina; Qiang, Yi; Reinhold, Joerg; Ron, Guy; Rosner, Guenther; Saha, Arunava; Sawatzky, Bradley; Shahinyan, Albert; Sirca, Simon; Slifer, Karl; Solvignon, Patricia; Sulkosky, Vince; Sulkosky, Vincent; Sulkosky, Vince; Sulkosky, Vincent; Urciuoli, Guido; Voutier, Eric; Watson, John; Weinstein, Lawrence; Wojtsekhowski, Bogdan; Wood, Stephen; Zheng, Xiaochao; Zhu, Lingyan

    2008-06-01

    The protons and neutrons in a nucleus can form strongly correlated nucleon pairs. Scattering experiments, in which a proton is knocked out of the nucleus with high-momentum transfer and high missing momentum, show that in carbon-12 the neutron-proton pairs are nearly 20 times as prevalent as proton-proton pairs and, by inference, neutron-neutron pairs. This difference between the types of pairs is due to the nature of the strong force and has implications for understanding cold dense nuclear systems such as neutron stars.

  8. The AdriaX Campaign: Meteo-Hydrological forecast and multi-radar observation in Central Adriatic

    NASA Astrophysics Data System (ADS)

    Maiello, Ida; Ferretti, Rossella

    2015-04-01

    In the framework of the IPA Adriatic Cross-Border Cooperation Programme the ADRIARadNet project planned a field campaign held during September-December 2014 for the western Adriatic regions (Marche and Abruzzo- Central Adriatic Operational, CAO) and to be held on January-March for the eastern side (Croatia and Albania - Southern Adriatic Operational, SAO). For the CAO region the X-band mini Radars recently installed in Tortoreto (Abruzzo) and Cingoli (Marche) have been operationally tested and used for studying special events occurred during the campaign. Moreover, in the framework of this project a dedicated model chain (coupling meteo and hydro) has been developed and implemented for the two areas CAO and SAO; specifically WRF-ARW (Weather Research Forecast meteorological model) high resolution output has been used to force CHyM (CETEMPS Hydrological Model). Several intensive observation periods (IOP) have been launched and among them the most relevant in terms of impact at the ground are presented in this study. During the IOPs radars data, measurements from surface stations and satellite data were collected together with operational forecast output to the aim of both verifying model performance and eventually to understand model failure and to study physical processes. The impact of the radars data assimilation on the precipitation forecast will be tested for a case of the CAO region by using 3DVAR data assimilation for WRF-ARW. The results for the CHyM hydrological simulation will be also discussed.

  9. The Istria yo-yo - evidence for millennial seismic cycle in the northern Adriatic

    NASA Astrophysics Data System (ADS)

    Kázmér, Miklós; Vrabec, Marko; Székely, Balázs

    2014-05-01

    The Istria Peninsula in the northern Adriatic Sea (Croatia and Slovenia) is considered to be a nearly aseismic part of the Adriatic microplate, as opposed to the seismically active frontal ranges of the highly active Dinaric orogen. New archaeoseismological data from the Medieval Eufrasius cathedral in Poreč on the west coast of Istria demonstrate two, previously unknown major earthquakes, which occured approx. a millennium apart. Evidence for slow coastal uplift alternating with rapid subsidence allows to identify the seismic cycle. A marine notch, otherwise an excellent marker of sea level, extends along a 240 km segment of the northern Adriatic rocky coast, from Trieste to Zadar. We interpret the following history of vertical displacements: (1) Slow uplift, evidenced by the 1-2 m high, roofed marine notch oversized with respect to the microtidal regime of the Adriatic Sea. 0.5-1 m deep notches were etched into the coast between ~3000 BC until the 4-6th century AD (Faivre et al., 2010). (2) Rapid submergence of the notch to 1-2 m depth below sea level, dated by the construction of successive cathedrals of Poreč built on increasingly higher ground at the seaside (4-6th century AD); submergence of Cissa town on Pag island in 361 AD. (3) Slow uplift of less than 2 m between the construction of the last, Eufrasius cathedral in the 4-6th century AD and the ~1440 AD earthquake. No conspicuous notch were etched in the rocky shore during this period. (4) Rapid submergence of terrestrial sediments below sea level after 1400 AD (Faivre et al., 2011). Major earthquake damage in Poreč cathedral just before 1440 AD. (5) Slow uplift after 1440 AD, corroborated by three decades of high-precision levelling and recent GPS data (Rezo et al., 2010). No conspicuous notch etched in the rocky shore during this period. (6) Next major earthquake with subsidence on land and uplift in the sea with tsunami... when? In our interpretation of the seismic cycle, Istria is slowly raised

  10. Dense crystalline packings of ellipsoids

    NASA Astrophysics Data System (ADS)

    Jin, Weiwei; Jiao, Yang; Liu, Lufeng; Yuan, Ye; Li, Shuixiang

    2017-03-01

    An ellipsoid, the simplest nonspherical shape, has been extensively used as a model for elongated building blocks for a wide spectrum of molecular, colloidal, and granular systems. Yet the densest packing of congruent hard ellipsoids, which is intimately related to the high-density phase of many condensed matter systems, is still an open problem. We discover an unusual family of dense crystalline packings of self-dual ellipsoids (ratios of the semiaxes α : √{α }:1 ), containing 24 particles with a quasi-square-triangular (SQ-TR) tiling arrangement in the fundamental cell. The associated packing density ϕ exceeds that of the densest known SM2 crystal [ A. Donev et al., Phys. Rev. Lett. 92, 255506 (2004), 10.1103/PhysRevLett.92.255506] for aspect ratios α in (1.365, 1.5625), attaining a maximal ϕ ≈0.758 06 ... at α = 93 /64 . We show that the SQ-TR phase derived from these dense packings is thermodynamically stable at high densities over the aforementioned α range and report a phase diagram for self-dual ellipsoids. The discovery of the SQ-TR crystal suggests organizing principles for nonspherical particles and self-assembly of colloidal systems.

  11. Down-core changes in molluscan death assemblages at Panzano Bay, an impacted area in the northern Adriatic Sea

    NASA Astrophysics Data System (ADS)

    Haselmair, Alexandra; Gallmetzer, Ivo; Stachowitsch, Michael; Tomasovych, Adam; Zuschin, Martin

    2016-04-01

    We use a historical ecology approach to shed light on the environmental history of the northern Adriatic Sea over the last hundreds to thousands of years. We focus on down-core changes in molluscan death assemblages, which serve as proxies for ecological shifts over time. The northern Adriatic Sea is particularly suited to study ecosystem modification under human pressure because it is among the most degraded marine ecosystems worldwide. We chose a sampling station in Panzano Bay, close the Isonzo River mouth and not far from the major industrial harbours of Trieste (Italy) and Koper (Slovenia), and traced down-core changes in molluscan community structure in correlation to major anthropogenic impacts that occurred here during the last centuries. Five sediment cores (1.5 m in length and diameters of 90 and 160 mm) were taken at a water depth of 12 m. We analysed grain size composition, the concentration of heavy metals and organic pollutants, and radiometrically dated the sediment using 210Pb. Furthermore, we dated shells of the abundant bivalve species Corbula gibba using 14C calibrated amino acid-racemisation (AAR). The whole molluscan community in the cores was analysed for species composition, abundance, taxonomic similarity, evidence for ecological interactions (i.e., frequencies of drilling predation) and taphonomic conditions of shells. The granulometric analysis shows that silt and clay dominate equally throughout the cores. Radiometric sediment dating revealed an average sedimentation rate of 2.5 mm/yr during the last 120 years. Shell dating points to a comparable overall core age, with only a few shell specimens being older than 500 years in the deepest core layer. In total, 10,452 mollusc individuals were analysed and 104 species identified. The most abundant bivalve species are Kurtiella bidentata, Corbula gibba and Abra nitida. Turritella communis and Nassarius pygmaeus are the most frequent gastropod species. Down-core changes in species composition

  12. Multi-Meteotsunami Event in the Adriatic Sea Generated by Atmospheric Disturbances of 25-26 June 2014

    NASA Astrophysics Data System (ADS)

    Šepić, Jadranka; Međugorac, Iva; Janeković, Ivica; Dunić, Natalija; Vilibić, Ivica

    2016-12-01

    A series of meteotsunamis hit a few locations in the Mediterranean and Black Seas during 22-27 June 2014. Meteotsunamis were particularly numerous on 25 and 26 June in the Adriatic Sea, where at least six harbours and bays were stricken by powerful waves: strongest events occurred in Vela Luka (Korčula Island), a known meteotsunami hot-spot, where waves reached height of 3 m, and in Rijeka dubrovačka Bay, where strong 5 m/s currents accompanied 2.5 m high waves. Intensification of high-frequency sea level activity was observed at both the eastern and western Adriatic tide gauge stations, with maximum recorded wave heights reaching 68 cm (Ortona, Italy). A series of individual air pressure disturbances characterized by pronounced rates of air pressure change (up to 2.4 hPa/5 min), limited spatial extent ( 50 km) and high temporal variability, propagated over the Adriatic on 2 days in question. Numerical hydrodynamic model SCHISM forced by measured and idealised air pressure disturbances was utilised to reproduce the observed Adriatic sea level response. Several important conclusions were reached: (1) meteotsunamis occurring at various parts of the coast were generated by different atmospheric air pressure disturbances; (2) topographic influence can be removed from sea level spectra by computing spectral signal-to-background ratios; the result, being related to the external forcing, resembles atmospheric pressure spectra; (3) sea response is strongly dependant on details of atmospheric forcing; and (4) over complex bathymetries, like the middle and south Adriatic ones, numerous effects, including Proudman resonance, edge waves, strong topographical enhancement and refractions on the islands placed on the pathway of atmospheric disturbances should be taken into account to fully understand meteotsunami generation and dynamics. An in-depth numerical study is planned to supplement the latter conclusion and to quantify contribution of each process.

  13. Dense fluids—New aspects and results

    NASA Astrophysics Data System (ADS)

    Franck, E. U.

    1986-05-01

    Dense fluids at elevated and supercritical temperatures find increased interest in science and technology. In this presentation special attention is given to binary mixtures with polar components. Methods and results of experiments with such high pressure-high temperature fluids are described. Far infrared spectra of CHCIF 2 and CHF 3 give indications of the types of molecular motion in the supercritical phases. “Enhancement factors” for the solubility of a solid solute like caffeine in high pressure CO 2 have been determined spectroscopically. The phase diagrams in the pressure-temperature-composition space and critical curves for water combined with nitrogen, oxygen, methane and helium have been measured recently to 2500 bar and 450°C. A “rational” equation of state permits calculation of critical curves and binodal surfaces for such systems. An extended investigation was made with the ternary system water-methane-sodium chloride. Small additions of salt shift critical curves by 100°C and more to higher temperatures. In water-methane mixtures between 400 and 500°C and at 1000 bar “supercritical flames” and “hydrothermal combustion” could be produced with injected oxygen. Binary liquid mixtures of cesium and cesium hydride to elevated hydrogen pressure and to 800°C show the phenomena of continuous transition from metal to ionic fluids. Electric conductance measurements in the whole range of concentrations are presented and discussed.

  14. Velocity coherence in dense cores

    NASA Astrophysics Data System (ADS)

    Goodman, Alyssa A.; Barranco, Joseph A.; Wilner, David J.; Heyer, Mark H.

    1997-02-01

    At the meeting, we presented a summary of two papers which support the hypothesis that the molecular clouds which contain star-forming low-mass dense cores are self-similar in nature on size scales larger than an inner scale, Rcoh, and that within Rcoh, the cores are ``coherent,'' in that their filling factor is large and they are characterized by a very small, roughly constant, mildly supersonic velocity dispersion. We expect these two papers, by Barranco & Goodman [1] and Goodman, Barranco, Wilner, & Heyer, to appear in the Astrophysical Journal within the coming year. Here, we present a short summary of our results. The interested reader is urged to consult the on-line version of this work at cfa-www.harvard.edu/~agoodman/vel_coh.html [2].

  15. Uniformly dense polymeric foam body

    DOEpatents

    Whinnery, Jr., Leroy

    2003-07-15

    A method for providing a uniformly dense polymer foam body having a density between about 0.013 g/cm.sup.3 to about 0.5 g/cm.sup.3 is disclosed. The method utilizes a thermally expandable polymer microsphere material wherein some of the microspheres are unexpanded and some are only partially expanded. It is shown that by mixing the two types of materials in appropriate ratios to achieve the desired bulk final density, filling a mold with this mixture so as to displace all or essentially all of the internal volume of the mold, heating the mold for a predetermined interval at a temperature above about 130.degree. C., and then cooling the mold to a temperature below 80.degree. C. the molded part achieves a bulk density which varies by less then about .+-.6% everywhere throughout the part volume.

  16. Neutrino Oscillations in Dense Matter

    NASA Astrophysics Data System (ADS)

    Lobanov, A. E.

    2017-03-01

    A modification of the electroweak theory, where the fermions with the same electroweak quantum numbers are combined in multiplets and are treated as different quantum states of a single particle, is proposed. In this model, mixing and oscillations of particles arise as a direct consequence of the general principles of quantum field theory. The developed approach enables one to calculate the probabilities of the processes taking place in the detector at long distances from the particle source. Calculations of higher-order processes, including computation of the contributions due to radiative corrections, can be performed in the framework of the perturbation theory using the regular diagram technique. As a result, the analog to the Dirac-Schwinger equation of quantum electrodynamics describing neutrino oscillations and its spin rotation in dense matter can be obtained.

  17. Extended thermodynamics of dense gases

    NASA Astrophysics Data System (ADS)

    Arima, T.; Taniguchi, S.; Ruggeri, T.; Sugiyama, M.

    2012-11-01

    We study extended thermodynamics of dense gases by adopting the system of field equations with a different hierarchy structure to that adopted in the previous works. It is the theory of 14 fields of mass density, velocity, temperature, viscous stress, dynamic pressure, and heat flux. As a result, most of the constitutive equations can be determined explicitly by the caloric and thermal equations of state. It is shown that the rarefied-gas limit of the theory is consistent with the kinetic theory of gases. We also analyze three physically important systems, that is, a gas with the virial equations of state, a hard-sphere system, and a van der Waals fluid, by using the general theory developed in the former part of the present work.

  18. DPIS for warm dense matter

    SciTech Connect

    Kondo, K.; Kanesue, T.; Horioka, K.; Okamura, M.

    2010-05-23

    Warm Dense Matter (WDM) offers an challenging problem because WDM, which is beyond ideal plasma, is in a low temperature and high density state with partially degenerate electrons and coupled ions. WDM is a common state of matter in astrophysical objects such as cores of giant planets and white dwarfs. The WDM studies require large energy deposition into a small target volume in a shorter time than the hydrodynamical time and need uniformity across the full thickness of the target. Since moderate energy ion beams ({approx} 0.3 MeV/u) can be useful tool for WDM physics, we propose WDM generation using Direct Plasma Injection Scheme (DPIS). In the DPIS, laser ion source is connected to the Radio Frequency Quadrupole (RFQ) linear accelerator directly without the beam transport line. DPIS with a realistic final focus and a linear accelerator can produce WDM.

  19. Carbonate chemistry dynamics and biological processes along a river-sea gradient (Gulf of Trieste, northern Adriatic Sea)

    NASA Astrophysics Data System (ADS)

    Ingrosso, Gianmarco; Giani, Michele; Cibic, Tamara; Karuza, Ana; Kralj, Martina; Del Negro, Paola

    2016-03-01

    In this paper we investigated, for two years and with a bi-monthly frequency, how physical, chemical, and biological processes affect the marine carbonate system in a coastal area characterized by high alkalinity riverine discharge (Gulf of Trieste, northern Adriatic Sea, Mediterranean Sea). By combining synoptic measurements of the carbonate system with in situ determinations of the primary production (14C incorporation technique) and secondary prokaryotic carbon production (3H-leucine incorporation) along a river-sea gradient, we showed that the conservative mixing between river endmember and off-shore waters was the main driver of the dissolved inorganic carbon (DIC) distribution and seasonal variation. However, during spring and summer seasons also the influence of biological uptake and release of DIC was significant. In the surface water of June 2012, the spreading and persistence of nutrient-rich freshwater stimulated the primary production (3.21 μg C L- 1 h- 1) and net biological DIC decrease (- 100 μmol kg- 1), reducing the dissolved CO2 concentration and increasing the pHT. Below the pycnocline of August 2012, instead, an elevated bacterial carbon production rate (0.92 μg C L- 1 h- 1) was related with net DIC increase (92 μmol kg- 1), low dissolved oxygen concentration, and strong pHT reduction, suggesting the predominance of bacterial heterotrophic respiration over primary production. The flux of carbon dioxide estimated at the air-sea interface exerted a low influence on the seasonal variation of the carbonate system. A complex temporal and spatial dynamic of the air-sea CO2 exchange was also detected, due to the combined effects of seawater temperature, river discharge, and water circulation. On annual scale the system was a sink of atmospheric CO2. However, in summer and during elevated riverine discharges, the area close to the river's mouth acted as a source of carbon dioxide. Also the wind speed was crucial in controlling the air-sea CO2

  20. Microbial processes and organic priority substances in marine coastal sediments (Adriatic Sea, Italy)

    NASA Astrophysics Data System (ADS)

    Zoppini, Annamaria; Ademollo, Nicoletta; Amalfitano, Stefano; Dellisanti, Walter; Lungarini, Silvia; Miserocchi, Stefano; Patrolecco, Luisa; Langone, Leonardo

    2015-04-01

    PERSEUS EU FP7 Project aims to identify the interacting patterns of natural and human-derived pressures to assess their impact on marine ecosystems and, using the objectives and principles of the Marine Strategy Framework Directive (MSFD) as a vehicle, to design an effective and innovative research governance framework based on sound scientific knowledge. In the frame of this Project (subtask 1.3.3 ADREX: Adriatic and Ionian Seas Experiment), monitoring surveys were conducted in the Adriatic Sea (Italy) in order to study the variation of structural and functional characteristics of native bacterial communities and the occurrence of selected classes of organic priority substances in sediments. The study area represents a good natural laboratory sensitive to climate variability and human pressure, owing to the semi-enclosed nature of the Adriatic Sea and to the increasing trend of human activities in the coastal regions. During the cruise ADRI-13 (November 2013) and ADRI-14 (October 2014) we sampled several coastal sites from the mouth of the Po River to the Otranto strait. Surface sediments were collected in all areas, while sediment cores were sampled in selected sites. Microbes associated with marine sediments play an important role in the C-flux being responsible for the transformation of organic detritus (autochthonous and allochthonous) into biomass. The sediment bacterial abundance was determined by epifluorescence microscopy and the rate of bacterial carbon production by measuring the 3H-leucine uptake rates. The community respiration rate was estimated by the measurement of the electron transport system (ETS) activity. The sediment contamination level was determined by measuring the concentration of contaminants included in the list of organic priority substances: PAHs, bisphenol A (BPA), alkylphenols (APs). The extraction/clean-up of PAHs, BPA and APs was performed by ultrasonic bath with the appropriate solvents, followed by analytical determination with

  1. An operational coupled wave-current forecasting system for the northern Adriatic Sea

    NASA Astrophysics Data System (ADS)

    Russo, A.; Coluccelli, A.; Deserti, M.; Valentini, A.; Benetazzo, A.; Carniel, S.

    2012-04-01

    Since 2005 an Adriatic implementation of the Regional Ocean Modeling System (AdriaROMS) is being producing operational short-term forecasts (72 hours) of some hydrodynamic properties (currents, sea level, temperature, salinity) of the Adriatic Sea at 2 km horizontal resolution and 20 vertical s-levels, on a daily basis. The main objective of AdriaROMS, which is managed by the Hydro-Meteo-Clima Service (SIMC) of ARPA Emilia Romagna, is to provide useful products for civil protection purposes (sea level forecasts, outputs to run other forecasting models as for saline wedge, oil spills and coastal erosion). In order to improve the forecasts in the coastal area, where most of the attention is focused, a higher resolution model (0.5 km, again with 20 vertical s-levels) has been implemented for the northern Adriatic domain. The new implementation is based on the Coupled-Ocean-Atmosphere-Wave-Sediment Transport Modeling System (COAWST)and adopts ROMS for the hydrodynamic and Simulating WAve Nearshore (SWAN) for the wave module, respectively. Air-sea fluxes are computed using forecasts produced by the COSMO-I7 operational atmospheric model. At the open boundary of the high resolution model, temperature, salinity and velocity fields are provided by AdriaROMS while the wave characteristics are provided by an operational SWAN implementation (also managed by SIMC). Main tidal components are imposed as well, derived from a tidal model. Work in progress is oriented now on the validation of model results by means of extensive comparisons with acquired hydrographic measurements (such as CTDs or XBTs from sea-truth campaigns), currents and waves acquired at observational sites (including those of SIMC, CNR-ISMAR network and its oceanographic tower, located off the Venice littoral) and satellite-derived wave-heights data. Preliminary results on the forecast waves denote how, especially during intense storms, the effect of coupling can lead to significant variations in the wave

  2. Comparison Between Numerical Simulations and Drifter Observations of the Surface Circulation in the Adriatic Sea

    NASA Astrophysics Data System (ADS)

    Korotenko, K. A.; Poulain, P. M.; Cushman-Roisin, B. R.

    2007-12-01

    Eulerian statistics computed from drifter data and estimated from numerical simulations of circulation of the Adriatic Sea are compared for different seasons and wind forcing. The periods of interest are August-October 2003, May, June and February 2003, where drifter data have high density. The numerical simulations were performed with a 1.2- min resolution DieCAST Ocean Circulation Model adapted for the Adriatic Sea. The simulations resolve the mesoscale variability because the grid size falls below the first baroclinic deformation radius (about 5-10 km) and the model has very low horizontal dissipation. The DieCAST model is initialized with seasonally averaged temperature and salinity data and forced with climatological winds and surface buoyancy fluxes (both heat flux and evaporation minus precipitation). River discharges are varied daily according to a perpetual year for every river, and the open-boundary conditions at Otranto Strait are obtained by nesting in two larger-scale models (Cushman-Roisin et al., JGR, 2007). In the period of interests the model was forced with the COAMPS wind stresses and heat fluxes. Mean Kinetic Energy (MKE) and Eddy Kinetic Energy (EKE) estimates were obtained using the methodology commonly used with drifter (Poulain, JMS, 2001). The surface drifter observations were obtained in 2002 and 2003 as part of the DOLCEVITA project (Ursella et al., JGR, 2006). More than 120 CODE drifters were released in the northern and middle Adriatic with the purpose of studying the surface circulation at mesoscale to seasonal scale in relation to wind forcing. Drifter velocities were low-pass filtered to eliminate tidal and inertial currents. Comparison of the MKE and EKE computed from the model and drifter data shows a good agreement for high- energy dynamics along the Italian coast and local effects of strong winds like Bora and Sirocco. Discrepancies between the drifter-based and model-inferred Eulerian statistics originates in the specification

  3. A multidisciplinary environmental integrated approach to better understand the Tegnue Reefs formation, offshore Chioggia, Northern Adriatic Sea.

    NASA Astrophysics Data System (ADS)

    Bergamasco, Andrea; Donnici, Sandra; Tosi, Luigi; Tagliapietra, Davide; Zaggia, Luca; Bonaldo, Davide; Braga, Federica; Da Lio, Cristina; Keppel, Erica; Lorenzetti, Giuliano; Manfè, Giorgia; Franceschini, Gianluca; Giovanardi, Otello; Carol, Eleonora; Fornaro, Elena; Grant, Carley

    2014-05-01

    , and benthic invertebrates like bryozoans, mollusks, serpulids and corals also contribute to the final building of the status of Tegnue's environment, but we want to demonstrate that the in first stage of consolidation abiotic phenomena could have played a major role. In order to prove our thesis a series of ground water sampling as well as rock sampling and sediment cores were carried out. The poster illustrates the overall ongoing program as well as some work in progress and first results from field cruise. Acknowledgments This work was supported by the Municipality of Chioggia through the Tegnue Project and partially by the Flagship Project RITMARE - The Italian Research for the Sea - coordinated by the Italian National Research Council and funded by the Italian Ministry of Education, University and Research within the National Research Program 2011-2013, and by the Scientific Cooperation Agreement between the CONICET (Argentina) - CNR (Italy), Program 2013-2014, Project 'Fresh-saltwaters in high-value coastlands: from the hydrogeophysical/geochemical characterization of the present interactions to the modeling quantification of the expected effects of climate changes'. References - Bonardi, M., Tosi, L. 2000. Indagini preliminari su alcune formazioni di sabbie cementate nella laguna di Venezia. In: La Ricerca Scientifica Per Venezia. Il Progetto Sistema Lagunare Veneziano, Modellistica del Sistema Lagunare Studio di Impatto Ambientale. Istituto Veneto di Scienze, Lettere ed Arti, Vol. II, Tomo II, p. 967-974, Venezia, ISBN: 88-86166-82-6. - Bonardi, M., Tosi, L., Rizzetto, F., Brancolini, G., Baradello, L. 2006. Effects of climate changes on the late Pleistocene and Holocene sediments of the Venice Lagoon, Italy. Journal of Coastal Research, SI 39, 279-284. - Casellato S., Stefanon A. 2008. Coralligenous habitat in the northern Adriatic Sea: an overview. Marine Ecology, 29: 321-341. - Gabbianelli, G., Colantoni, P., Degetto, S., Dinelli, E., Lucchini, F. 1997

  4. Thermochemistry of dense hydrous magnesium silicates

    NASA Technical Reports Server (NTRS)

    Bose, Kunal; Burnley, Pamela; Navrotsky, Alexandra

    1994-01-01

    Recent experimental investigations under mantle conditions have identified a suite of dense hydrous magnesium silicate (DHMS) phases that could be conduits to transport water to at least the 660 km discontinuity via mature, relatively cold, subducting slabs. Water released from successive dehydration of these phases during subduction could be responsible for deep focus earthquakes, mantle metasomatism and a host of other physico-chemical processes central to our understanding of the earth's deep interior. In order to construct a thermodynamic data base that can delineate and predict the stability ranges for DHMS phases, reliable thermochemical and thermophysical data are required. One of the major obstacles in calorimetric studies of phases synthesized under high pressure conditions has been limitation due to the small (less than 5 mg) sample mass. Our refinement of calorimeter techniques now allow precise determination of enthalpies of solution of less than 5 mg samples of hydrous magnesium silicates. For example, high temperature solution calorimetry of natural talc (Mg(0.99) Fe(0.01)Si4O10(OH)2), periclase (MgO) and quartz (SiO2) yield enthalpies of drop solution at 1044 K to be 592.2 (2.2), 52.01 (0.12) and 45.76 (0.4) kJ/mol respectively. The corresponding enthalpy of formation from oxides at 298 K for talc is minus 5908.2 kJ/mol agreeing within 0.1 percent to literature values.

  5. Model For Dense Molecular Cloud Cores

    NASA Technical Reports Server (NTRS)

    Doty, Steven D.; Neufeld, David A.

    1997-01-01

    We present a detailed theoretical model for the thermal balance, chemistry, and radiative transfer within quiescent dense molecular cloud cores that contain a central protostar. In the interior of such cores, we expect the dust and gas temperatures to be well coupled, while in the outer regions CO rotational emissions dominate the gas cooling and the predicted gas temperature lies significantly below the dust temperature. Large spatial variations in the gas temperature are expected to affect the gas phase chemistry dramatically; in particular, the predicted water abundance varies by more than a factor of 1000 within cloud cores that contain luminous protostars. Based upon our predictions for the thermal and chemical structure of cloud cores, we have constructed self-consistent radiative transfer models to compute the line strengths and line profiles for transitions of (12)CO, (13)CO, C(18)O, ortho- and para-H2(16)O, ortho- and para-H2(18)O, and O I. We carried out a general parameter study to determine the dependence of the model predictions upon the parameters assumed for the source. We expect many of the far-infrared and submillimeter rotational transitions of water to be detectable either in emission or absorption with the use of the Infrared Space Observatory (ISO) and the Submillimeter Wave Astronomy Satellite. Quiescent, radiatively heated hot cores are expected to show low-gain maser emission in the 183 GHz 3(sub 13)-2(sub 20) water line, such as has been observed toward several hot core regions using ground-based telescopes. We predict the (3)P(sub l) - (3)P(sub 2) fine-structure transition of atomic oxygen near 63 micron to be in strong absorption against the continuum for many sources. Our model can also account successfully for recent ISO observations of absorption in rovibrational transitions of water toward the source AFGL 2591.

  6. Defining conservation units in a stocking-induced genetic melting pot: unraveling native and multiple exotic genetic imprints of recent and historical secondary contact in Adriatic grayling

    PubMed Central

    Meraner, Andreas; Cornetti, Luca; Gandolfi, Andrea

    2014-01-01

    The definition of conservation units is crucial for the sustainable management of endangered species, though particularly challenging when recent and past anthropogenic and natural gene flow might have played a role. The conservation of the European grayling, Thymallus thymallus, is particularly complex in its southern distribution area, where the Adriatic evolutionary lineage is endangered by a long history of anthropogenic disturbance, intensive stocking and potentially widespread genetic introgression. We provide mtDNA sequence and microsatellite data of 683 grayling from 30 sites of Adriatic as well as Danubian and Atlantic origin. We apply Bayesian clustering and Approximate Bayesian Computation (ABC) to detect microgeographic population structure and to infer the demographic history of the Adriatic populations, to define appropriate conservation units. Varying frequencies of indigenous genetic signatures of the Adriatic grayling were revealed, spanning from marginal genetic introgression to the collapse of native gene pools. Genetic introgression involved multiple exotic source populations of Danubian and Atlantic origin, thus evidencing the negative impact of few decades of stocking. Within the Adige River system, a contact zone of western Adriatic and eastern Danubian populations was detected, with ABC analyses suggesting a historical anthropogenic origin of eastern Adige populations, most likely founded by medieval translocations. Substantial river-specific population substructure within the Adriatic grayling Evolutionary Significant Unit points to the definition of different conservation units. We finally propose a catalog of management measures, including the legal prohibition of stocking exotic grayling and the use of molecular markers in supportive- and captive-breeding programs. PMID:24834328

  7. The performance of dense medium processes

    SciTech Connect

    Horsfall, D.W.

    1993-12-31

    Dense medium washing in baths and cyclones is widely carried out in South Africa. The paper shows the reason for the preferred use of dense medium processes rather than gravity concentrators such as jigs. The factors leading to efficient separation in baths are listed and an indication given of the extent to which these factors may be controlled and embodied in the deployment of baths and dense medium cyclones in the planning stages of a plant.

  8. Cadmium and total mercury in some cephalopods from the South Adriatic Sea (Italy).

    PubMed

    Storelli, M M; Marcotrigiano, G O

    1999-06-01

    In the framework of a wide monitoring programme on the presence of heavy metals in marine organisms caught in the South Adriatic Sea, cadmium and total mercury concentrations were determined in flesh and hepatopancreas of 512 specimens of two species of cephalopods. The aim of the study was to establish the quality of the marine food with respect to the health of consumers and to investigate cadmium and mercury distribution in organisms representing different habitats. For both elements, higher levels were found in spider octopus (Octopus salutii) than in broadtail squid (Illex coindeti). Between the two different tissues analysed, higher concentrations were observed in hepatopancreas than flesh. According to the rules in force, no flesh sample showed cadmium and total mercury concentrations exceeding the peak permitted values of 2 mg/kg wet wt and 0.5 mg/kg wet wt respectively.

  9. Regional approach to modeling the transport of floating plastic debris in the Adriatic Sea.

    PubMed

    Liubartseva, S; Coppini, G; Lecci, R; Creti, S

    2016-02-15

    Sea surface concentrations of plastics and their fluxes onto coastlines are simulated over 2009-2015. Calculations incorporate combinations of terrestrial and maritime litter inputs, the Lagrangian model MEDSLIK-II forced by AFS ocean current simulations, and ECMWF wind analyses. With a relatively short particle half-life of 43.7 days, the Adriatic Sea is defined as a highly dissipative basin where the shoreline is, by construction, the main sink of floating debris. Our model results show that the coastline of the Po Delta receives a plastic flux of approximately 70 kg(km day)(-1). The most polluted sea surface area (>10 g km(-2) floating debris) is represented by an elongated band shifted to the Italian coastline and narrowed from northwest to southeast. Evident seasonality is found in the calculated plastic concentration fields and the coastline fluxes. Complex source-receptor relationships among the basin's subregions are quantified in impact matrices.

  10. Northern Adriatic LNG receiving terminal: Pre-feasibility study. Part 1. Export trade information

    SciTech Connect

    Not Available

    1991-03-19

    The study evaluated 2 potential sites as the location for a Liquefied Natural Gas (LNG) receiving terminal. The study assumed that the LNG will be obtained in Algeria and transported, via liquefied gas carriers, to either Koper or Omisalj, located on the Northern Adriatic coast of Yugoslavia. The proposed terminal will provide natural gas, via pipeline, to Austria, Czechoslovakia, Hungary and Yugoslavia. The goal of the study was to determine specific transportation and processing costs, per cubic meter of gas, at each delivery station in Yugoslavia and at the respective custody transfer points. Consideration has been given to the overall costs for construction, maintenance and operation, as well as marine transport for the gas and capital equipment of the system.

  11. Bioaccumulation of arsenic species in rays from the northern Adriatic Sea.

    PubMed

    Šlejkovec, Zdenka; Stajnko, Anja; Falnoga, Ingrid; Lipej, Lovrenc; Mazej, Darja; Horvat, Milena; Faganeli, Jadran

    2014-12-01

    The difference in arsenic concentration and speciation between benthic (Pteromylaeus bovinus, Myliobatis aquila) and pelagic rays (Pteroplatytrygon violacea) from the northern Adriatic Sea (Gulf of Trieste) in relation to their size (age) was investigated. High arsenic concentrations were found in both groups with tendency of more efficient arsenic accumulation in benthic species, particularly in muscle (32.4 to 362 µg·g-1 of total arsenic). This was attributed to species differences in arsenic access, uptake and retention. In liver most arsenic was present in a form of arsenobetaine, dimethylarsinic acid and arsenoipids, whereas in muscle mainly arsenobetaine was found. The good correlations between total arsenic/arsenobetaine and size reflect the importance of accumulation of arsenobetaine with age. Arsenobetaine is an analogue of glycine betaine, a known osmoregulator in marine animals and both are very abundant in mussels, representing an important source of food for benthic species P. bovinus and M. aquila.

  12. The Clodia database: a long time series of fishery data from the Adriatic Sea.

    PubMed

    Mazzoldi, Carlotta; Sambo, Andrea; Riginella, Emilio

    2014-01-01

    Long-term time series of species abundances can depict population declines and changes in communities in response to anthropogenic activities, climate changes, alterations of trophic relationships. Here we present a database of historical marine fishery landing data, covering a remarkably long time series (1945-2013) and referring to one of the most exploited areas of the Mediterranean Sea, the Adriatic Sea. The database includes two time series of landing data, 1945-2013 and 1997-2013, from the official statistics of the fish market of Chioggia, where the major fishing fleet of the area operates. Comparisons between the landing data of the database and landing data from other fisheries or data from scientific surveys support the reliability of the time series in depicting changes in species abundances. The database is expected to be used by fishery biologists and ecologists interested in depicting and understanding temporal variations in species abundances and community composition, in relation to environmental and anthropogenic factors.

  13. Historical pattern and mass balance of trace metals in sediments of the northwestern Adriatic Sea Shelf.

    PubMed

    Romano, Stefania; Langone, Leonardo; Frignani, Mauro; Albertazzi, Sonia; Focaccia, Paola; Bellucci, Luca Giorgio; Ravaioli, Mariangela

    2013-11-15

    In view of the recent action in Marine Strategy Framework Directive, reconstructing the history of anthropogenic metal inputs and calculating the budgets for the northwestern part of the Italian Adriatic basin can provide a benchmark for comparison with new evidences and enlighten recent environmental changes. Among the metals, the attention was focused on Pb and Zn, as they provide the most significant anthropogenic signals. In 1988, areal distributions clearly identified the Po, Adige and Brenta rivers as the main sources of contaminants. The study area was divided in three compartments. The area in front of the Po delta represented a sink for metals but the accumulation of Zn and Pb integrated over the entire study area suggests an effective export throughout southern boundary. Most concentration-depth/year profiles in cores showed an upward increase from the Italian Unification (1861), with a still significant anthropogenic supply at the time of sampling.

  14. Post-mortem investigations on a leatherback turtle Dermochelys coriacea stranded along the Northern Adriatic coastline.

    PubMed

    Poppi, Lisa; Zaccaroni, Annalisa; Pasotto, Daniela; Dotto, Giorgia; Marcer, Federica; Scaravelli, Dino; Mazzariol, Sandro

    2012-08-13

    Leatherback sea turtles Dermochelys coriacea are regularly reported in the Mediterranean Sea but rarely reach the northern Adriatic Sea. In the summer of 2009, a well-preserved carcass of an adult female of this species was found dead along the coast of Lido di Venezia. A complete necropsy was carried out, along with evaluation of levels of tissue trace elements. The the post-mortem revealed acute severe bacterial gastroenteritis caused by Photobacterium damselae ssp. piscicida, an opportunistic agent that infected an apparently debilitated animal weakened by ingested plastic debris. High levels of heavy metals (Hg, Pb, Cd and As) found in the liver and kidneys might have contributed to the animal's demise. These findings support previous indications that marine debris is one of the major threats to marine animals, particularly for critically endangered species such as the leatherback turtle.

  15. Bioaccumulation of Arsenic Species in Rays from the Northern Adriatic Sea

    PubMed Central

    Šlejkovec, Zdenka; Stajnko, Anja; Falnoga, Ingrid; Lipej, Lovrenc; Mazej, Darja; Horvat, Milena; Faganeli, Jadran

    2014-01-01

    The difference in arsenic concentration and speciation between benthic (Pteromylaeus bovinus, Myliobatis aquila) and pelagic rays (Pteroplatytrygon violacea) from the northern Adriatic Sea (Gulf of Trieste) in relation to their size (age) was investigated. High arsenic concentrations were found in both groups with tendency of more efficient arsenic accumulation in benthic species, particularly in muscle (32.4 to 362 µg·g−1 of total arsenic). This was attributed to species differences in arsenic access, uptake and retention. In liver most arsenic was present in a form of arsenobetaine, dimethylarsinic acid and arsenoipids, whereas in muscle mainly arsenobetaine was found. The good correlations between total arsenic/arsenobetaine and size reflect the importance of accumulation of arsenobetaine with age. Arsenobetaine is an analogue of glycine betaine, a known osmoregulator in marine animals and both are very abundant in mussels, representing an important source of food for benthic species P. bovinus and M. aquila. PMID:25470025

  16. Performance analysis of coupled and uncoupled hydrodynamic and wave models in the northern Adriatic Sea

    NASA Astrophysics Data System (ADS)

    Busca, Claudia; Coluccelli, Alessandro; Valentini, Andrea; Benetazzo, Alvise; Bonaldo, Davide; Bortoluzzi, Giovanni; Carniel, Sandro; Falcieri, Francesco; Paccagnella, Tiziana; Ravaioli, Mariangela; Riminucci, Francesco; Sclavo, Mauro; Russo, Aniello

    2014-05-01

    The complex dynamics of the Adriatic Sea are the result of geographical position, orography and bathymetry, as well as rivers discharge and meteorological conditions that influence, more strongly, the shallow northern part. Such complexity requires a constant monitoring of marine conditions in order to support several activities (marine resources management, naval operations, emergency management, shipping, tourism, as well as scientific ones). Platforms, buoys and mooring located in Adriatic Sea supply almost continuously real time punctual information, which can be spatially extended, with some limitations, by drifters and remote sensing. Operational forecasting systems represent valid tools to provide a complete tridimensional coverage of the area, with a high spatial and temporal resolution. The Hydro-Meteo-Clima Service of the Emilia-Romagna Environmental Agency (ARPA-SIMC, Bologna, Italy) and the Dept. of Life and Environmental Sciences of Università Politecnica delle Marche (DISVA-UNIVPM, Ancona, Italy), in collaboration with the Institute of Marine Science of the National Research Council (ISMAR-CNR, Italy) operationally run several wave and hydrodynamic models on the Adriatic Sea. The main implementations are based on the Regional Ocean Modeling System (ROMS), the wave model Simulating WAves Nearshore (SWAN), and the coupling of the former two models in the Coupled Ocean-Atmosphere-Wave-Sediment Transport (COAWST) system. Horizontal resolutions of the different systems range from the 2 km of AdriaROMS to the 0.5 km of the recently implemented northern Adriatic COAWST. Forecasts are produced every day for the subsequent 72 hour with hourly resolution. All the systems compute the fluxes exchanged through the interface with the atmosphere from the numerical weather prediction system named COSMO-I7, an implementation for Italy of the Consortium for Small-scale Modeling (COSMO) model, at 7 km horizontal resolution. Considering the several operational

  17. Harmful Algae Records in Venice Lagoon and in Po River Delta (Northern Adriatic Sea, Italy)

    PubMed Central

    Bilaničovà, Dagmar; Marcomini, Antonio

    2014-01-01

    A detailed review of harmful algal blooms (HAB) in northern Adriatic Sea lagoons (Po River Delta and Venice lagoon) is presented to provide “updated reference conditions” for future research and monitoring activities. In the study areas, the high mollusc production requires the necessity to identify better methods able to prevent risks for human health and socioeconomical interests. So, an integrated approach for the identification and quantification of algal toxins is presented by combining microscopy techniques with Liquid Chromatography coupled with High Resolution Time of Flight Mass Spectrometry (HPLC-HR-TOF-MS). The method efficiency was first tested on some samples from the mentioned coastal areas, where Dinophysis spp. occurred during summer in the sites directly affected by seawaters. Although cell abundance was always <200 cells/L, the presence of Pectenotoxin-2 (PTX2), detected by HPLC-HR-TOF-MS, indicated the potential release of detectable amounts of toxins even at low cell abundance. PMID:24683360

  18. Impact of fish farming on the distribution of phosphorus in sediments in the middle Adriatic area.

    PubMed

    Matijević, Slavica; Kuspilić, Grozdan; Kljaković-Gaspić, Zorana; Bogner, Danijela

    2008-03-01

    During the last decade, intensive fish farming developed along the central Croatian coast, creating a need to study and evaluate its potential influence on unaffected sites. We considered phosphorus as an indicator of the influence of fish farming and investigated the distribution of phosphorus forms in sediment from several fish farms and marine areas of different trophic status in the middle Adriatic. Analyses of samples were performed with modified SEDEX techniques. Our results indicated that authigenic apatite phosphorus showed no significant differences among the investigated stations, while organic phosphorus concentrations reflected the trophic status of the station area. Below-cage sediment was characterized by enhanced fish debris phosphorus and low detrital apatite phosphorus concentrations, while sediment from an anthropogenically influenced bay showed the highest values of iron bound phosphorus species. Among the different P fractions, fish debris phosphorus proved to be the most sensitive indicator of the influence of fish farming on marine sediment.

  19. Life-history traits and population decline of the Atlantic mackerel Scomber scombrusin the Adriatic Sea.

    PubMed

    Meneghesso, C; Riginella, E; La Mesa, M; Donato, F; Mazzoldi, C

    2013-11-01

    This study investigated demographic structure and reproductive characteristics of the Atlantic mackerel Scomber scombrus, in relation to landing trends in the northern-central Adriatic Sea. Results highlighted the occurrence of only small-sized and young-age individuals, and a marked decline from the 1990s to the present in maximum age (from 8 to 3 years) and total length (L(T); from 420 to 360 mm). Fecundity ranged between 40,000 and 190,000 eggs, and was related to female L(T). High levels of atresia implied lower values of actual fecundity. Sexual maturity was attained by 72·8% of individuals in their first year of life at 200 mm. The reduction in maximum L(T) resulted in a marked decline in the population egg production, while the reduction in maximum age implied that females participated in fewer spawning events.

  20. Spatial pattern and weight of seabed marine litter in the northern and central Adriatic Sea.

    PubMed

    Strafella, P; Fabi, G; Spagnolo, A; Grati, F; Polidori, P; Punzo, E; Fortibuoni, T; Marceta, B; Raicevich, S; Cvitkovic, I; Despalatovic, M; Scarcella, G

    2015-02-15

    The present study analyzes spatial distribution and typology of marine litter on the seabed in the FAO Geographical Sub-Area 17 (northern and central Adriatic Sea). Two surveys were conducted during fall 2011 and 2012 and 67 stations were sampled each year. Litter items were collected using the "rapido" trawl, a modified beam trawl commonly used by the Italian fishermen to catch flat fish and other benthic species. Marine litter in the catches was sorted and classified in 6 major categories (plastic, metal, glass, rubber, wood, other). Plastic litter was further subdivided in 3 sub-categories based on its source: fishing nets, aquaculture nets and other. Plastic was dominant in terms of weight followed by metal and other categories. The highest concentration of litter was found close to the coast likely as a consequence of high coastal urbanization, river inflow and extensive navigation associated with the morphological and hydrological features of the basin.

  1. North Adriatic Tides: Observations, Variational Data Assimilation Modeling, and Linear Tide Dynamics

    DTIC Science & Technology

    2009-12-01

    in the North Adriatic as GEOFIZIKA, VOL. 26, NO. 2, 2009, 115–143 117 70 60 50 4030 20 20 50 80 80 SS2 SS4 SS5 SS6 SS8 SS9 SS10KB1 CP2 CP3 VR1 VR2 VR4...59 SS10 44.4812 N 14.2904 E 51 CP2 44.4610 N 12.8551 E 42 CP3 44.5402 N 13.1245 E 42 KB1 44.7507 N 14.0213 E 48 VR1 45.3139 N 12.5081 E 17...applied to these values to account for the inferred (but unexplained) counter-clockwise compass bias in the VR5 measurements (see Section 2.1). CP2 CP3

  2. Dense module enumeration in biological networks

    NASA Astrophysics Data System (ADS)

    Tsuda, Koji; Georgii, Elisabeth

    2009-12-01

    Analysis of large networks is a central topic in various research fields including biology, sociology, and web mining. Detection of dense modules (a.k.a. clusters) is an important step to analyze the networks. Though numerous methods have been proposed to this aim, they often lack mathematical rigorousness. Namely, there is no guarantee that all dense modules are detected. Here, we present a novel reverse-search-based method for enumerating all dense modules. Furthermore, constraints from additional data sources such as gene expression profiles or customer profiles can be integrated, so that we can systematically detect dense modules with interesting profiles. We report successful applications in human protein interaction network analyses.

  3. SWASV speciation of Cd, Pb and Cu for the determination of seawater contamination in the area of the Nicole shipwreck (Ancona coast, Central Adriatic Sea).

    PubMed

    Annibaldi, Anna; Illuminati, Silvia; Truzzi, Cristina; Scarponi, Giuseppe

    2011-12-01

    The study reports for the first time on the heavy metal contamination of the waters surrounding a shipwreck lying on the sea floor. Square wave anodic stripping voltammetry has been used for a survey of the total and dissolved Cd, Pb and Cu contents of the seawater at the site of the sinking of the Nicole M/V (Coastal Adriatic Sea, Italy). Results show that the hulk has a considerable impact as regards all three metals in the bottom water, especially for the particulate fraction concentrations, which increased by factors of ≈ 9 (Cd), ≈ 3 (Pb) and ≈ 5 (Cu). The contaminated plume extended downstream for about 2 miles. Much lower contamination was observed for dissolved bottom concentrations; nevertheless Pb (0.56 ± 0.03 nmol/L) is higher than the Italian legal limits established for 2015 and Cd (0.23 ± 0.03 nmol/L) is very close the limit of Cd will be exceeded if the hulk is not removed.

  4. On the analysis of an extreme Bora wind event over the northern Adriatic Sea

    NASA Astrophysics Data System (ADS)

    Colucci, R. R.; Pucillo, A.

    2010-09-01

    On 10th March 2010 a severe Bora wind event affected the Friuli Venezia Giulia region, northeastern Italy, in particular the gulf of Trieste area (northern Adriatic Sea). Such event has been driven by a widespread westward moving cold pool aloft, coming from the Western Asia, that brought an intense potential vorticity anomaly over the western Mediterranean Sea. It determined a deep cyclogenesis involving all the troposphere. The pressure gradient force in the lowest layers forced a northeastern wind to blow with noticeable strength over the gulf of Trieste area and the Karstic region. The mean ground wind velocity has reached values above 27 m/s (about 100 km/h) for several hours, and maximum gusts exceeded 42 m/s (about 150 km/h) over Trieste town. The northeastern sector of the Adriatic Sea is frequently affected by strong Bora events in particular during the winter semester. This is a characteristic local wind mostly influenced by the orography of the Karstic relieves to the east of Trieste town. The target of this work is to assess the climatological relevance of such an event by comparing it with the most representative events of the past. It has been possible thanks to the long term archive of meteorological observations in Trieste site (I.R. Accademia di Commercio e Nautica, Regio Comitato Talassografico Italiano, Ministero dell'Agricoltura e Foreste, Consiglio Nazionale delle Ricerche): we have found out that this is one of the ten strongest Bora event along the 1871-2010 period. Considerations about the trend and frequency of severe Bora events have been proposed.

  5. Technical Note: Medium-term morphodynamics in an unprotected sandy beach of the Adriatic Sea

    NASA Astrophysics Data System (ADS)

    Postacchini, M.; Soldini, L.; Lorenzoni, C.; Mancinelli, A.

    2015-08-01

    In the recent years attention has been paid to the beach protection by means of soft and hard defenses. Along the Italian coasts of the Adriatic Sea, sandy beaches are the most common landscapes and around 70 % of the Marche-Region coasts (central Adriatic), is protected by defense structures. The longest free-from-obstacle nearshore area in the Region includes the beach of Senigallia, characterized by a multiple barred beach, frequently monitored during the last decades. The bathymetries surveyed in 2006, 2010, 2011, 2012 and 2013 show a good adaptation of the beach to the Dean-type equilibrium profile, though a strong short-/medium-term variability of the wave climate has been observed during the monitored periods. This suggests a slight influence of wave forcing on the long-term profiles, which seems to only depend on the sediment size. Further, the medium-term dynamics of the submerged bars and their geometric features have been related to the wave climate collected by a wave buoy located 40 km off Senigallia during the analyzed temporal windows. An overall interpretation of the complete dynamics, i.e. hydrodynamics (buoy data), sediment characteristics (equilibrium-profile A parameter) and morphodynamics (bathymetric surveys), suggests that the wave climate is fundamental for the morphodynamic changes of the beach in the medium term: waves coming from NNE/ESE are characterized by a larger/smaller steepness and induce seaward/shoreward bar migration, as well as bar smoothing/steepening. Moving southward, the bar dimension increases, while the equilibrium profile suggests a decrease of the sediment size in the submerged beach, this probably due to the presence of both harbor jetty and river mouth North of the investigated area.

  6. Phytoplankton cell lysis associated with polyunsaturated aldehyde release in the Northern Adriatic Sea.

    PubMed

    Ribalet, François; Bastianini, Mauro; Vidoudez, Charles; Acri, Francesco; Berges, John; Ianora, Adrianna; Miralto, Antonio; Pohnert, Georg; Romano, Giovanna; Wichard, Thomas; Casotti, Raffaella

    2014-01-01

    Diatoms are able to react to biotic and abiotic stress, such as competition, predation and unfavorable growth conditions, by producing bioactive compounds including polyunsaturated aldehydes (PUAs). PUAs have been shown to act against grazers and either enhance or inhibit the growth of different phytoplankton and bacteria both in culture and in the field. Presence of nanomolar concentrations of dissolved PUAs in seawater has been reported in the North Adriatic Sea (Mediterranean), suggesting that these compounds are released in seawater following diatom cell lysis. However, the origin of the PUAs and their effects on natural phytoplankton assemblages remain unclear. Here we present data from four oceanographic cruises that took place during diatom blooms in the northern Adriatic Sea where concentrations of particulate and dissolved PUAs were monitored along with phytoplankton cell lysis. Cell lysis was positively correlated with both concentrations of particulate and dissolved PUAs (R = 0.69 and R = 0.77, respectively), supporting the hypothesis that these compounds are released by cell lysis. However, the highest concentration of dissolved PUAs (2.53 nM) was measured when cell lysis was high (0.24 d(-1)) but no known PUA-producing diatoms were detected, suggesting either that other organisms can produce PUAs or that PUA-producing enzymes retain activity extracellularly after diatom cells have lysed. Although in situ concentrations of dissolved PUAs were one to three orders of magnitude lower than those typically used in laboratory culture experiments, we argue that concentrations produced in the field could induce similar effects to those observed in culture and therefore may help shape plankton community composition and function in the oceans.

  7. Identity of Squalius (Actinopterygii, Cyprinidae) from Istra Peninsula in Croatia (Adriatic Sea basin).

    PubMed

    Zupancic, Primoz; Mrakovcic, Milorad; Marcic, Zoran; Naseka, Alexander M; Bogutskaya, Nina G

    2010-08-27

    A chub of previously ambiguous identity from the Boljunscica and Pazincica rivers (south-eastern Istra Peninsula) was studied and compared with geographically close Squalius squalus, Squalius zrmanja, and Squalius janae recently described from the Dragonja River drainage in the Adriatic Sea basin in Slovenia. It was shown that the chub from the south-eastern Istra Peninsula differs from all know species of Squalius but one: Squalius janae. Three samples examined from Boljunscica and Pazincica rivers and Squalius janae from its type locality, Dragonja River, show the following characters typical for the latter species: a long head (the head length 27-32% SL); a pointed conical snout with a clearly projecting upper jaw; a long straight mouth cleft, the lower jaw length (39-45% HL) exceeding the caudal peduncle depth; a large eye; commonly 9? branched anal-fin rays; commonly 44 total vertebrae (24+20 or 25+19); bright silvery colouration, scales easily lost; iris, pectoral, pelvic and anal fin pigmentation with yellow shades. The data on the distribution of Squalius chubs in the northern Adriatic basin support the assumption that the range of Squalius janae is determined by the geology of the Trieste Flysch Basin and the Pazin Flysch Basin forming the base of the Istra Peninsula. The distribution pattern of this species does not support a simple model of fish dispersal and a complete connectivity within the whole Palaeo-Po historical drainage. Indeed, it indicates a disrupted surface palaeohydrography that was heavily fragmented by karstification in the whole Dinaric area.

  8. Gastrointestinal helminth community of loggerhead sea turtle Caretta caretta in the Adriatic Sea.

    PubMed

    Gračan, Romana; Buršić, Moira; Mladineo, Ivona; Kučinić, Mladen; Lazar, Bojan; Lacković, Gordana

    2012-07-25

    We analysed the intestinal helminth community of 70 loggerhead sea turtles Caretta caretta with a curved carapace length ranging from 25 to 85.4 cm, recovered dead in neritic foraging habitats in the Adriatic Sea in 1995 to 2004. The overall prevalence of infection was high (70.0%), with a mean abundance of 36.8 helminth parasites per turtle. Helminth fauna comprised 5 trematodes (Calycodes anthos, Enodiotrema megachondrus, Orchidasma amphiorchis, Pachypsolus irroratus, Rhytidodes gelatinosus) and 3 nematodes (Sulcascaris sulcata, Anisakis spp., Hysterothylacium sp.), with 6 taxa specific for marine turtles. In terms of infection intensity and parasite abundance, O. amphiorchis was the dominant species (mean intensity: 49.8; mean abundance: 12.8), followed by R. gelatinosus (30.5 and 8.3, respectively) and P. irroratus (23.5 and 7.0, respectively), while larval Anisakis spp. exhibited the highest prevalence (34.3%). The intensity of helminth infection ranged from 1 to 302 (mean: 52.6 ± 69.1) and was not correlated with the size of turtles; this relationship held for all species, except R. gelatinosus (rS = 0.556, p < 0.05). In comparison to other marine habitats, the helminth community of Adriatic loggerheads is characterised by higher species diversity (Shannon-Wiener H' = 1.58) and evenness (E = 0.76), and lower dominance values (Berger-Parker d = 0.35), which can be attributed to the life history and feeding ecology of sea turtles in recruited neritic grounds and the diversity of their benthic prey.

  9. Mitochondrial DNA and Y-chromosome diversity in East Adriatic sheep.

    PubMed

    Ferencakovic, M; Curik, I; Pérez-Pardal, L; Royo, L J; Cubric-Curik, V; Fernández, I; Alvarez, I; Kostelic, A; Sprem, N; Krapinec, K; Goyache, F

    2013-04-01

    Variation in mitochondrial DNA (mtDNA) and Y-chromosome haplotypes was analysed in nine domestic sheep breeds (159 rams) and 21 mouflon (Ovis musimon) sampled in the East Adriatic. Mitochondrial DNA analyses revealed a high frequency of type B haplotypes, predominantly in European breeds, and a very low frequency of type A haplotypes, which are more frequent in some Asian breeds. Mitochondrial haplotype Hmt-3 was the most frequent (26.4%), and 37.1%, 20.8% and 7.6% of rams had haplotypes one, two and three mutations remote from Hmt-3 respectively. In contrast, Y-chromosome analyses revealed extraordinary paternal allelic richness: HY-6, 89.3%; HY-8, 5.0%; HY-18, 3.1%; HY-7, 1.3%; and HY-5, 1.3%. In fact, the number of haplotypes observed is comparable to the number found in Turkish breeds and greater than the number found in European breeds so far. Haplotype HY-18 (A-oY1/135-SRYM18), identified here for the first time, provides a link between the haplotype HY-12 (A-oY1/139-SRYM18) found in a few rams in Turkey and haplotype HY-9 (A-oY1/131-SRYM18) found in one ram in Ethiopia. All mouflons had type B mtDNA haplotypes, including the private haplotype (Hmt-55), and all were paternally monomorphic for haplotype HY-6. Our data support a quite homogeneous maternal origin of East Adriatic sheep, which is a characteristic of European breeds. At the same time, the high number of haplotypes found was surprising and intriguing, and it begs for further analysis. Simultaneous analysis of mtDNA and Y-chromosome information allowed us to detect a large discrepancy between maternal and paternal lineages in some populations. This is most likely the result of breeder efforts to 'upgrade' local populations using rams with different paternal origins.

  10. Concentration of selected trace elements and PCBs in sediments from the Adriatic Sea

    SciTech Connect

    Fowler, S W; Hamilton, T F; Coquery, M; Villeneuve, J-P; Horvat, M

    2000-07-26

    A broad baseline study of the levels and distributions of trace metals and PCB compounds in sediments has been undertaken. PCB concentrations in surface sediments reflect the source of these contaminates in the region. The highest PCB concentrations as Aroclor 1260 (approximately 10 ng g{sup -1}) were found in sediments near the outflow of the Po river. The lowest concentrations (1.5 ng g{sup -1} dry) were associated with the sediments from the Jabuka Pit in the Middle Adriatic. These values are quite similar to total PCBs (<1.0-17) measured in surface sediments sampled off the coast of Croatia in 1977-78. Thus, based on the limited amount of new data available, it appears that there has been little, if any, decrease in PCB loading in Adriatic sediments over the past 15 years. Downcore profiles of PCBs in sediment cores are also discussed from a pollution history standpoint. Likewise, total mercury in surface sediments was also highest at stations off the Po (403-499 ng g{sup -1} dry) and lowest (67-224 ng g{sup -1}) in the Jabuka Pit. In one core located just south of the Po outflow, total Hg concentrations at all depths were relatively high decreasing gradually from approximately 400 ng g{sup -1} in the top 4 cm to roughly 200 ng g{sup -1} at a depth of 32 cm. Using a {sup 210}Pb-derived sedimentation rate of 0.26 em Y{sup -1} for this station, it appears that anthropogenic inputs of mercury may have been responsible for the gradual increase in total mercury noted over the last 125 years.

  11. Water Conditioner

    NASA Technical Reports Server (NTRS)

    1991-01-01

    A home use water treatment incorporates technology developed to purify water aboard Space Shuttle Orbiters. The General Ionics Model IQ Bacteriostatic Water Softener softens water and inhibits bacteria growth in the filtering unit. Ionics used NASA silver ion technology as a basis for development of a silver carbon dense enough to remain on top of the water softening resin bed.

  12. Seasonal dynamics and long-term trend of hypoxia in the coastal zone of Emilia Romagna (NW Adriatic Sea, Italy).

    PubMed

    Alvisi, Francesca; Cozzi, Stefano

    2016-01-15

    Long-term series of meteorological, hydrological and oceanographic data were compared with hypoxia occurrence, in order to define characteristics and trends of this phenomenon in the Emilia Romagna Coastal Zone (ERCZ) in 1977-2008. During this period, hypoxia was recorded at all sampling stations, up to 20 km offshore. In winter, spring and late autumn, hypoxia appearance was matched to significant positive anomalies of air and surface seawater temperatures (up to +3.6 °C), whereas this effect was less pronounced in August-October. Hypoxia generally occurred with scarce precipitation (0-2 dm(3)m(2)d(-1)) and low wind velocity (0-2 ms(-1)), suggesting the importance of stable meteo-marine conditions for the onset of this phenomenon. Nevertheless, wind direction emerged as an indicator of hydrodynamic seasonal changes in the area and is thus a hypoxia regulator. In winter, spring and autumn, hypoxia was favored by large increases of biomass induced by river freshets. In contrast, summer hypoxia occurred during periods of low runoff, suggesting that pronounced stratification and weak circulation of coastal waters were more important in this season. Since the 1990s, a shift from widespread summer hypoxia to local hypoxia irregularly distributed across the year has occurred. This process was concomitant to long-term increases of air temperature (+0.14 °C yr(-1)), wind speed (+0.03 ms(-1) yr(-1)) and salinity (+0.09 yr(-1)), and decreases of Po River flow (-0.54 km(3) yr(-1)), oxygen saturation (-0.2% yr(-1)) and PO4(3-) (-0.004 μmol P L(-1) yr(-1)) and NH4(+) (-0.04 μmol N L(-1) yr(-1)) concentrations in surface coastal waters. Despite that several of these changes suggest an ERCZ trophic level positive reduction, similar to that reported for the N Adriatic, the concomitant climate warming might further exacerbate hypoxia in particularly shallow shelf locations. Therefore, in order to avoid hypoxia development a further mitigation of anthropogenic pressure is still

  13. Optimal probabilistic dense coding schemes

    NASA Astrophysics Data System (ADS)

    Kögler, Roger A.; Neves, Leonardo

    2017-04-01

    Dense coding with non-maximally entangled states has been investigated in many different scenarios. We revisit this problem for protocols adopting the standard encoding scheme. In this case, the set of possible classical messages cannot be perfectly distinguished due to the non-orthogonality of the quantum states carrying them. So far, the decoding process has been approached in two ways: (i) The message is always inferred, but with an associated (minimum) error; (ii) the message is inferred without error, but only sometimes; in case of failure, nothing else is done. Here, we generalize on these approaches and propose novel optimal probabilistic decoding schemes. The first uses quantum-state separation to increase the distinguishability of the messages with an optimal success probability. This scheme is shown to include (i) and (ii) as special cases and continuously interpolate between them, which enables the decoder to trade-off between the level of confidence desired to identify the received messages and the success probability for doing so. The second scheme, called multistage decoding, applies only for qudits ( d-level quantum systems with d>2) and consists of further attempts in the state identification process in case of failure in the first one. We show that this scheme is advantageous over (ii) as it increases the mutual information between the sender and receiver.

  14. Adriatic Meteorology

    DTIC Science & Technology

    2003-09-30

    positioned at the Croatian coastal town of Zadar (see following image of the launch of a balloon sounding at Zadar ) . This station was set-up but...a-day Zadar soundings between 1 January – 30 June and twice-a-day operational soundings at Zagreb. Figure 1. Start of sounding at Zadar ...Meteorological Service was contracted to double the number of upper air soundings at the Croatian coastal station of Zadar (44.10 N 15.34 E , 79 m/MSL

  15. Coastal vulnerability and the implications of sea level rise between the cities of Pescara and Ortona (Adriatic Sea - Central Italy)

    NASA Astrophysics Data System (ADS)

    Tarragoni, C.; Bellotti, P.; Caputo, C.; Davoli, L.; Evangelista, S.; Pugliese, F.; Raffi, R.; Lupia Palmieri, E.

    2012-04-01

    Geomorphic processes induce rapid environmental changes especially along the coast that is highly susceptible to them. In addiction, the effects of storm or wave may be amplified by the expected relative sea level rise. In a context, like Italian coast, where the almost part of coast is densely populated and many infrastructures are presents, it is very important to have adequate tools to urban planning like the coastal vulnerability map. In this study the preliminary results of the ongoing SECOA project (Solution for Environmental contrasts in COastal Areas; 7th Framework Program) are presented, with reference to the Adriatic coast between Pescara and Ortona cities, in the Abruzzo region. In this work the same analytical model applied in the Venice Lagoon has been employed (Fontolan, 2001; 2005) involving the evaluation of the effective vulnerability (Ve). Ve is calculated as the difference between the potential vulnerability (Vp) and the defence elements present along the coast (D). (Ve = Vp - D) The data used to measure quantitative features are: high-resolution DEM (LiDAR), satellite images, aero photos, bathymetric profiles and topographic maps. The variables that contribute to the evaluation are: beach amplitude, berm height, seafloor gradient, seafloor evolution, recent and historical shorelines evolution for Vp; height, slope, vegetation cover, presence of passages, incipient dunes and windbreak barriers for the dune and anthropic barriers height. In this context, the potential vulnerability results from the sum of each variable (Vn) per the relative efficacy coefficient (Kn): Vp = V1K1+V2K2+ …VnKn In the same way the defences result from the sum of each kind of defence per the relative efficacy coefficient: D = D1K1+ …. DnKn The coastal area between Pescara and Ortona cities has been segmented in different sectors characterized by homogeneous values of the considered variables and for each of these the Ve values have been calculated and referred to one

  16. Oil spill hazard from dispersal of oil along shipping lanes in the Southern Adriatic and Northern Ionian Seas.

    PubMed

    Liubartseva, S; De Dominicis, M; Oddo, P; Coppini, G; Pinardi, N; Greggio, N

    2015-01-15

    An assessment of hazard stemming from operational oil ship discharges in the Southern Adriatic and Northern Ionian (SANI) Seas is presented. The methodology integrates ship traffic data, the fate and transport oil spill model MEDSLIK-II, coupled with the Mediterranean Forecasting System (MFS) ocean currents, sea surface temperature analyses and ECMWF surface winds. Monthly and climatological hazard maps were calculated for February 2009 through April 2013. Monthly hazard distributions of oil show that the zones of highest sea surface hazard are located in the southwestern Adriatic Sea and eastern Ionian Sea. Distinctive "hot spots" appear in front of the Taranto Port and the sea area between Corfu Island and the Greek coastlines. Beached oil hazard maps indicate the highest values in the Taranto Port area, on the eastern Greek coastline, as well as in the Bari Port area and near Brindisi Port area.

  17. Spreading patterns of the invasive Caulerpa cylindracea Sonder along the west Istrian Coast (northern Adriatic Sea, Croatia).

    PubMed

    Iveša, Ljiljana; Djakovac, Tamara; Devescovi, Massimo

    2015-06-01

    The northern Adriatic Sea represents the northernmost and thus the coldest biogeographic sector of the Mediterranean Sea. In 2004, the invasive green alga Caulerpa cylindracea was recorded for the first time in the northern Adriatic at a site of the west Istrian Coast. Until 2010, additional C. cylindracea mats have only formed up to 7 km northward from the first colonisation site. Subsequently, the alga was also recorded at sites widespread along the entire coast. Both the first 2004 colonisation event and the 2011-2014 colonisation of distant sites occurred during periods of winter seawater temperatures higher than 9 °C. In general, algal spreading was markedly slow. Approximately 10 years after the first record, C. cylindracea has affected less than 1% of the entire west Istrian coastline. The colonisation predominantly occurred in ports and urbanised bays (seaside resorts) suggesting that anthropogenic activities might enhance algal diffusion.

  18. Mass occurrence of the ctenophore Bolinopsis vitrea (L. Agassiz, 1860) in the nearshore southern Adriatic Sea (Kotor Bay, Montenegro).

    PubMed

    Lucic, Davor; Pestoric, Branka; Malej, Alenka; Lopez-Lopez, Lucia; Drakulovic, Dragana; Onofri, Vladimir; Miloslavic, Marijana; Gangai, Barbara; Onofri, Ivona; Benovic, Adam

    2012-08-01

    The ctenophore Bolinopsis vitrea has been rarely observed in the Mediterranean Sea. A bloom of B. vitrea is here reported for the first time in the southern Adriatic Sea in the spring and summer of 2009, together with its effect on the plankton of Kotor Bay. Ctenophores were found below 5 m depth only. Results of the investigation indicate that mass occurrence of B. vitrea could have a great impact on the Kotor Bay ecosystem. Their predation on copepods would reduce grazing pressure on phytoplankton, favouring an uncommon bloom of the latter. It is evident that B. vitrea are capable of altering rapidly the composition and biomass of coastal plankton communities when present in large masses. This first evidence of such events for this species may indicate changes in the functioning of marine ecosystems of the southern Adriatic.

  19. Total assemblages of benthic foraminifera from a mixed siliciclastic/carbonate inner shelf; preliminary results from the bays of Soline and Nin (Adriatic Sea, Croatia)

    NASA Astrophysics Data System (ADS)

    Vidović, J.; Ćosović, V.; Juračić, M.; Benac, Č.

    2012-04-01

    Eastern Adriatic shelf is mixed siliciclastic/carbonate area with a great proportion of carbonate biogenous production. This study presents analysis and comparison of total benthic foraminiferal assemblages (their composition, diversity and distribution) in surface sediments from two Eastern Adriatic shallow water bays (Soline and Nin Bay), sampled seasonally from 2006 to 2008. In order to characterize the carbonate sediment production, 62 samples along the bathymetric profiles (from 2 to 20 m) were collected by scuba diving with short PVC corers. Granulometrical analysis was done using method of wet sieving. Statistical analyses (cluster analysis, PCA) were performed using Past program. The most abundant biogenous components in different sediments from Soline Bay (muddy sandy gravel and mud) are foraminifera, followed by fragments of mollusks, gastropods, bryozoans and sea urchins. Foraminiferal assemblages are high diversified as confirmed by Shannon-Wiener index varying from 2.14 to 3.39, Fisher α index from 5.74 to 16.30 and Equitability from 0.32 to 0.72. The shallowest part of the bay is covered with the sand, consisted of high proportion of siliciclastic component and impoverished in biogenous remnants. Foraminiferal assemblages have low diversity (Shannon-Wiener index 1.36, Fisher α index 2.31 and Equitability 0.32). Throughout Nin Bay, sediments (classified as sand, muddy sand and mud) are consisted of various biogenic remnants. Foraminiferal assemblages have high biodiversity, with Shannon-Wiener index varying from 2.51 to 3.20, α-Fisher index from 7.84 to 12.64 and Equitability from 0.37 to 0.77. Statistical analyses (cluster analysis and PCA) grouped foraminifera in two major assemblages, related to sediment type. On sandy and gravely substrates, assemblage is dominated by epifaunal genera and species: Quinqueloculina sp. (6-20%), Elphidium sp. (5-16%), Neoconorbina terquemi (6-10 %) and Asterigerinata mamilla (5-7%). Infaunal species, Ammonia

  20. Holocene seasonal sea-surface temperature variations in the southern Adriatic Sea inferred from a multiproxy approach

    NASA Astrophysics Data System (ADS)

    Sangiorgi, Francesca; Capotondi, Lucilla; Combourieu Nebout, Nathalie; Vigliotti, Luigi; Brinkhuis, Henk; Giunta, Simona; Lotter, Andrè F.; Morigi, Caterina; Negri, Alessandra; Reichart, Gert-Jan

    2003-12-01

    Holocene cooling events have been reconstructed for the southern Adriatic Sea (central Mediterranean) by means of analyses of organic walled dinoflagellate cysts, planktonic foraminifera, oxygen isotopes, calcareous nanoplankton, alkenones and pollen from a sediment core. Two cooling events have been detected, during which sea-surface temperatures (SSTs) were ca. 2°C lower. Unravelling the SST signal into dominant seasonal components suggests maximum winter cooling of 2°C at around 6.0 ka, whereas the cooling at ca. 3.0 ka might be the result of a spring temperature cooling of 2-3°C. The events, lasting several hundred years, are apparently synchronous with those in the Aegean Sea, where they have been related to known cooling events from the Greenland ice-core record. A distinct interruption in Adriatic Sea sapropel S1 is not clearly accompanied by a local drop in winter temperatures, but seems to be forced by ventilation, which probably occurred earlier in the Aegean Sea and was subsequently transmitted to the Adriatic Sea. Copyright

  1. Scarcity of parasite assemblages in the Adriatic-reared European sea bass (Dicentrarchus labrax) and sea bream (Sparus aurata).

    PubMed

    Mladineo, Ivona; Petrić, Mirela; Segvić, Tanja; Dobričić, Nikolina

    2010-11-24

    The shaping forces of parasite community structure still is the main subject in the ecological parasitology whilst community predictability and repeatability showed that hardly a generally applicable role is ever going to be assessed. Defining and describing parasite communities can be very useful from the epizootiological point, in order to help in the assessment of the medical and economical impact of certain parasitosis, moreover when hosts are economically valuable species. Since parasite assemblages in reared European sea bass (Dicentrarchus labrax) and sea bream (Sparus aurata) in Adriatic cage systems can play an important role in the economic feasibility of the rearing process, we evaluated their character through assessing diversity indices, nestedness of parasite communities and their differences in respect to season and composition, as well as fish growth. We observed colonization of a new monogenean species (Furnestinia echeneis) and general impoverishment of parasites populations over time in the Adriatic-reared fish parasite assemblages. Parasite assemblages differed significantly between seasons for both fish species, while species richness, evenness, diversity indices and nestedness of parasitic communities in the sea bream showed to be significantly higher compared to those in the sea bass. Such characteristics define parasite communities of both Adriatic-reared fish as species poor although structured and ordered assemblages.

  2. Model study of the ship emissions impact on the air quality in the Adriatic/Ionian area

    NASA Astrophysics Data System (ADS)

    Karagiannidis, Athanasios; Poupkou, Anastasia; Liora, Natalia; Dimopoulos, Spiros; Giannaros, Christos; Melas, Dimitrios; Argiriou, Athanassios

    2015-04-01

    The increase of the ship traffic for touristic and commercial purposes is one of the EU Blue Growth targets. The Adriatic/Ionian is one of the sea-basin strategic areas for this target. The purpose of the study is the examination of the impact of the ship emissions on the gaseous and particulate pollutants concentrations in the Adriatic/Ionian area for which the current scientific knowledge is limited. The impact is simulated over a domain covering the Central and Eastern Mediterranean in 10 km resolution during a summer period (July) and a winter period (January) of the year 2012. The modeling system used consists of the photochemical model CAMx off line coupled with the meteorological model WRF. The zero-out modeling method is implemented involving CAMx simulations performed while including and omitting the ship emission data. The simulations are based on the European scale anthropogenic emission inventory of The Netherlands Organisation (TNO) for the reference year 2009. Natural emissions (NMVOCs from the vegetation, sea salt, wind-blown dust), estimated with the use of the Natural Emission MOdel (NEMO) developed by the Aristotle University of Thessaloniki, are accounted for in the photochemical model runs. The spatial distribution of the resulting differences in the gaseous and particulate pollutant concentration fields for both emission scenarios are presented and discussed, providing an estimation of the contribution of ship emissions on the determination of the air quality in the Adriatic/Ionian countries

  3. Surface current patterns in the northern Adriatic extracted from high-frequency radar data using self-organizing map analysis

    NASA Astrophysics Data System (ADS)

    Mihanović, Hrvoje; Cosoli, Simone; Vilibić, Ivica; Ivanković, Damir; Dadić, Vlado; GačIć, Miroslav

    2011-08-01

    A network of high-frequency (HF) radars was installed in the northern Adriatic in the second half of 2007, aimed to measure surface currents in the framework of the North Adriatic Surface Current Mapping (NASCUM) project. This study includes a detailed analysis of current measurements from February to August 2008, a period in which three radars were simultaneously operational. Current patterns and temporal evolutions of different physical processes were extracted by using self-organizing map (SOM) analysis. The analysis focused on subtidal frequency band and extracted 12 different circulation patterns on a 4 × 3 rectangular SOM grid. The SOM was also applied on a joint data set that included contemporaneous surface wind data obtained from the operational hydrostatic mesoscale meteorological model ALADIN/HR. The strongest currents were recorded during energetic bora episodes, being recognized by several current patterns and having the characteristic downwind flow with magnitudes exceeding 35 cm/s at some grid points. Another characteristic wind, the sirocco, was represented by three current patterns, while the remaining current structures were attributed to weak winds and the residual thermohaline circulation. A strong resemblance has been found between SOM patterns extracted from HF radar data only and from combined HF radar and wind data sets, revealing the predominant wind influence to the surface circulation structures and their temporal changes in the northern Adriatic. These results show the SOM analysis being a valuable tool for extracting characteristic surface current patterns and forcing functions.

  4. Dynamic shear jamming in dense suspensions

    NASA Astrophysics Data System (ADS)

    Peters, Ivo; Majumdar, Sayantan; Jaeger, Heinrich

    Shear a dense suspension of cornstarch and water hard enough, and the system seems to solidify as a result. Indeed, previous studies have shown that a jamming front propagates through these systems until, after interaction with boundaries, a jammed solid spans across the system. Because these fully jammed states are only observed if the deformation is fast enough, a natural question to ask is how this phenomenon is related to the discontinuous shear thickening (DST) behavior of these suspensions. We present a single experimental setup in which we on the one hand can measure the rheological flow curves, but on the other hand also determine if the suspension is in a jammed state. This we do by using a large-gap cylindrical Couette cell, where we control the applied shear stress using a rheometer. Because our setup only applies shear, the jammed states we observe are shear-jammed, and cannot be a result of an overall increase in packing fraction. We probe for jammed states by dropping small steel spheres on the surface of the suspension, and identify elastic responses. Our experiments reveal a clear distinction between the onset of DST and Shear-Jammed states, which have qualitatively different trends with packing fraction close to the isotropic jamming point.

  5. Bacterial community shift is induced by dynamic environmental parameters in a changing coastal ecosystem (northern Adriatic, northeastern Mediterranean Sea)--a 2-year time-series study.

    PubMed

    Tinta, T; Vojvoda, J; Mozetič, P; Talaber, I; Vodopivec, M; Malfatti, F; Turk, V

    2015-10-01

    The potential link between the microbial dynamics and the environmental parameters was investigated in a semi-enclosed and highly dynamic coastal system (Gulf of Trieste, northern Adriatic Sea, NE Mediterranean Sea). Our comprehensive 2-year time-series study showed that despite the shallowness of this area, there was a significant difference between the surface and the bottom bacterial community structure. The bottom bacterial community was more diverse than the surface one and influenced by sediment re-suspension. The surface seawater temperature had a profound effect on bacterial productivity, while the bacterial community structure was more affected by freshwater-borne nutrients and phytoplankton blooms. Phytoplankton blooms caused an increase of Gammaproteobacteria (Alteromonadaceae, SAR86 and Vibrionaceae) and shift in dominance from SAR11 to Rhodobacteraceae taxon at the surface. Our results propose the importance of the water mass movements as drivers of freshwater-borne nutrients and of allochthonous microbial taxa. This study emphasizes the prediction power based on association networks analyses that are fed with long-term measurements of microbial and environmental parameters. These interaction maps offer valuable insights into the response of marine ecosystem to climate- and anthropogenic-driven stressors.

  6. A combinated approach to investigate the biochemistry and hydrography of a shallow bay in the south Adriatic Sea: the Gulf of Manfredonia (Italy).

    PubMed

    Focardi, S; Specchiulli, A; Spagnoli, F; Fiesoletti, F; Rossi, C

    2009-06-01

    The main goal of this study is to understand the hydrological and biochemical set up and processes of a marine coastal area located in the western side of the south Adriatic sea (the gulf of Manfredonia) by the use of both satellite images and in situ investigations A water sampling in the gulf of Manfredonia was performed at 18 fixed stations in June 2003; physico-chemical and biological parameters (temperature, salinity, dissolved oxygen and fluorescence) were measured along the water column and water samples were collected to analyse dissolved nutrients (ammonia, nitrite, nitrate, phosphate and silicate), total nutrients (nitrogen and phosphorus), chlorophyll a and total suspended solids. Surface spatial distributions of field collected data were examined to characterize biochemical and hydrographic conditions of the Gulf of Manfredonia and these results were related with the remote sensing analysis data. Remote sensed data (obtained by Landsat 7 TM and Modis Terra) were processed to obtain maps of chlorophyll a, temperature and optical characteristics of the gulf; these maps were compared to in situ data. From physico-chemical measurements no stratification was observed in the water column except for the south-eastern area. High concentrations of silicate and ammonia were observed in the northern zone of the gulf, while nitrate, phosphate, chlorophyll a and total suspended solids distributions showed higher values in the central coastal zone. These results were confirmed by remote sensing analysis; Modis elaboration showed a distribution with higher concentrations of chlorophyll a near the coast and Landsat images highlighted the extension of the surrounding agricultural areas crossed by the two main rivers which discharge into the gulf. The integration between field data with the remote sensing analysis showed to be a valid support in coastal zone management.

  7. Dense-spray properties: Structure and turbulence modulation

    NASA Astrophysics Data System (ADS)

    Ruff, G. A.; Parthasarathy, R. N.; Faeth, G. M.

    1989-08-01

    A theoretical and experimental study of aspects of dense sprays is described, considering: the structure and mixing properties of the near injector, dense spray region of pressure atomized sprays; and the direct effect of particle (drop) motion on the turbulence properties of multiphase flows (which is often called turbulence modulation). The structure of dense sprays was studied using large scale (9.5 and 19.1 mm jet exit diameters) water sprays in still air. Measurements included: flow visualization using flash photography; liquid volume fractions using gamma ray absorption; streamwise mean and fluctuating velocities at the injector exit, and entrainment velocities, using laser velocimetry; and dispersed phase properties using single- and double-flash holography. Predictions based on the locally homogeneous flow (LHF) approximation of multiphase flow theory were evaluated using the measurements. Measurements showed that mixing was strongly influenced by the degree of flow development at the injector exit and the breakup regime: fully developed flow and atomization breakup yielded the fastest mixing rates. Turbulence modulation was studied by considering nearly monodisperse spherical glass particles falling in a stagnant water bath, where effects of turbulence modulation were responsible for the entire turbulence field. Measurements included phase velocities, as well as the temporal and spatial correlations of continuous phase velocities, using a two-point phase discriminating laser velocimeters, and calibration of particle motion properties using motion picture shadowgraphs.

  8. Sea level rise of semi-enclosed basins: deviation of Adriatic and Baltic sea level from the mean global value.

    NASA Astrophysics Data System (ADS)

    Scarascia, Luca; Lionello, Piero

    2015-04-01

    Future sea level rise (SL), which represents today one of the major threats that are caused by climate change, will not be uniform. Regional differences are crucial for 40% of the world population, which is located in the coastal zone. To explore the mechanisms linking regional SL to climate variables is very important in order to provide reliable future projections. This study focuses on two semi-enclosed basins, the Adriatic and Baltic Sea and investigates the deviation of their SL from the mean global value. In fact, past deviations of the SL of these two basins from the global value have been observed and can be attributed to large scale factors (such as teleconnections) and regional factors, such as the inverse barometric effect, the wind stress, the thermosteric and halosteric effects. The final goal of this work is to assess to which extent the Adriatic and Baltic SL will depart from the mean global value in the next decades and at the end of 21st century. This is achieved by analyzing deviations of the mean SL of the Baltic and Adriatic Sea from the global mean SL during the 20th century and investigating which factors can explain such deviations. A multivariate linear regression model is built and used to describe the link between three large scale climate variables which are used as predictors (mean sea level pressure, surface air temperature and precipitation), and the regional SL deviation (the predictand), computed as the difference between the regional and the global SL. At monthly scale this linear regression model provides a good reconstruction of the past variability in the cold season during which it explains 60%-70% of the variance. Summer reconstruction is substantially less successful and it represents presently the main limit of the model skill. This linear regression model, forced by predictors extracted from CMIP5 multi-model simulations, is used to provide projections of SL in the Adriatic and Baltic Sea. On the basis of the projections

  9. Submarine landslides in the Southern Adriatic basin: good candidates for potential paleoseismic analysis.

    NASA Astrophysics Data System (ADS)

    Dalla Valle, Giacomo; Trincardi, Fabio; Foglini, Federica; Campiani, Elisabetta; Pellegrini, Claudio

    2016-04-01

    The Plio-Pleistocene sedimentary succession of the western continental margin that surround the Southern Adriatic basin mainly consists of contourite depositional systems. The architectural stacking pattern of the contourites-linked bodies is sometimes interrupted by the presence of large-scale mass-transport complexes (MTCs). MTCs are spatially diffused along the margin and are characterized by high variability in size, morphology and geometries. In the northern sector of the margin MTCs derive from the remobilisation of upper-slope contourite drifts, whereas in the southern sector of the margin sedimentary instability involves shelf-margin, progradational deposits. The most prominent MTC of the northern sector of the margin is the Gondola Slide (GS) a large, deep-seated MTC composed of at least three distinct MTDs involving up to 40km3 of sediments. The events that have generated these MTDs have been enclosed within a robust chronological framework using sedimentary shallow piston-cores collected along the continental slope. The reconstruction of the age of these MTDs indicates that failures have repeatedly occurred along the margin during at least the last 55,000 years. Therefore, the GS case indicates that sediment instability processes can span a large portion of a sea-level cycle, pointing to triggering mechanisms that are independent from variations in the relative sea level position. The repeated GS failure events are therefore interpreted to be mainly triggered by earthquake shocks. The Southern Adriatic basin represents a seismically active area and earthquakes are generally cluster along long-lived shear zones. One of these zones, the Gondola Zone, which run across the shelf and the slope, close to the GS-MTC, has been site of paleoseismology analysis, indicating recent (younger than 5.5 kyr) tectonic deformation through E-W strike-slip faulting . Basin-scale MTDs characterize also the southern sector of the continental margin. MTDs are present both

  10. Common sole in the northern and central Adriatic Sea: Spatial management scenarios to rebuild the stock

    NASA Astrophysics Data System (ADS)

    Scarcella, Giuseppe; Grati, Fabio; Raicevich, Saša; Russo, Tommaso; Gramolini, Roberto; Scott, Robert D.; Polidori, Piero; Domenichetti, Filippo; Bolognini, Luca; Giovanardi, Otello; Celić, Igor; Sabatini, Laura; Vrgoč, Nedo; Isajlović, Igor; Marčeta, Bojan; Fabi, Gianna

    2014-05-01

    The northern and central Adriatic Sea represents an important spawning and aggregation area for common sole (Solea solea) and provides for around 20% of the Mediterranean landings. In this area, this resource is mainly exploited with rapido trawl and set nets. The stock is not yet depleted and faces a situation of growth overfishing. The comparison between the spatial distribution by age of S. solea and the geographic patterns of the rapido trawl fishing effort evidenced an overlapping of this fishing activity with the area where juveniles concentrate (age groups 0-2). The majority of spawners inhabits specific offshore areas, here defined as ‘sole sanctuaries', where high concentrations of debris and benthic communities make difficult trawling with rapido. The aim of this study was to evaluate existing spatial management regimes and potential new spatial and temporal closures in the northern and central Adriatic Sea using a simple modelling tool. Two spatial simulations were carried out in order to verify the effectiveness of complementary methods for the management of fisheries: the ban of rapido trawling from October to December within 6 nautical miles and 9 nautical miles of the Italian coast. The focus of the simulation is that the effort of the rapido trawl is moved far from the coast during key sole recruitment periods, when the juveniles are moving from the inshore nursery area toward the offshore feeding grounds. The management scenarios showed that a change in selectivity would lead to a clear increase in the spawning stock biomass and an increase in landings of S. solea in the medium-term. The rapido trawl activity could be managed by using a different logic, bearing in mind that catches and incomes would increase with small changes in the spatial pattern of the fishing effort. The present study highlights the importance of taking into account spatial dimensions of fishing fleets and the possible interactions that can occur between fleets and target

  11. Dynamical theory of dense groups of galaxies

    NASA Technical Reports Server (NTRS)

    Mamon, Gary A.

    1990-01-01

    It is well known that galaxies associate in groups and clusters. Perhaps 40% of all galaxies are found in groups of 4 to 20 galaxies (e.g., Tully 1987). Although most groups appear to be so loose that the galaxy interactions within them ought to be insignificant, the apparently densest groups, known as compact groups appear so dense when seen in projection onto the plane of the sky that their members often overlap. These groups thus appear as dense as the cores of rich clusters. The most popular catalog of compact groups, compiled by Hickson (1982), includes isolation among its selection critera. Therefore, in comparison with the cores of rich clusters, Hickson's compact groups (HCGs) appear to be the densest isolated regions in the Universe (in galaxies per unit volume), and thus provide in principle a clean laboratory for studying the competition of very strong gravitational interactions. The $64,000 question here is then: Are compact groups really bound systems as dense as they appear? If dense groups indeed exist, then one expects that each of the dynamical processes leading to the interaction of their member galaxies should be greatly enhanced. This leads us to the questions: How stable are dense groups? How do they form? And the related question, fascinating to any theorist: What dynamical processes predominate in dense groups of galaxies? If HCGs are not bound dense systems, but instead 1D change alignments (Mamon 1986, 1987; Walke & Mamon 1989) or 3D transient cores (Rose 1979) within larger looser systems of galaxies, then the relevant question is: How frequent are chance configurations within loose groups? Here, the author answers these last four questions after comparing in some detail the methods used and the results obtained in the different studies of dense groups.

  12. Magnetic Phases in Dense Quark Matter

    SciTech Connect

    Incera, Vivian de la

    2007-10-26

    In this paper I discuss the magnetic phases of the three-flavor color superconductor. These phases can take place at different field strengths in a highly dense quark system. Given that the best natural candidates for the realization of color superconductivity are the extremely dense cores of neutron stars, which typically have very large magnetic fields, the magnetic phases here discussed could have implications for the physics of these compact objects.

  13. Dissociation energy of molecules in dense gases

    NASA Technical Reports Server (NTRS)

    Kunc, J. A.

    1992-01-01

    A general approach is presented for calculating the reduction of the dissociation energy of diatomic molecules immersed in a dense (n = less than 10 exp 22/cu cm) gas of molecules and atoms. The dissociation energy of a molecule in a dense gas differs from that of the molecule in vacuum because the intermolecular forces change the intramolecular dynamics of the molecule, and, consequently, the energy of the molecular bond.

  14. Microbial degradation at a shallow coastal site: Long-term spectra and rates of exoenzymatic activities in the NE Adriatic Sea

    NASA Astrophysics Data System (ADS)

    Celussi, Mauro; Del Negro, Paola

    2012-12-01

    The degradation of organic matter along the water column is mediated by enzymes released into the environment by planktonic organisms. Variations in enzymes profiles (types and levels of activity) reflect the trophic status of the environment and could be caused by shifts in the dominant species or in the level of enzyme expression by the same species in response to changes in the spectrum of organic substrates. To explore this issue, we examined the maximum rates of hydrolysis of 6 different enzymes (protease, α-glucosidase, β-glucosidase, β-galactosidase, alkaline phosphatase and lipase) along the water column (4 depths) at a coastal station in the Gulf of Trieste (northern Adriatic Sea), from 2000 to 2005. Most of the studied enzymes exhibited a pronounced seasonal variability with winter minima and maxima from April to October. During summer, alkaline phosphatase, lipase and protease reached the highest activities, while polysaccharide degradation prevailed in spring and autumn, associated to phytoplankton blooms. Phosphatase/protease activities ratio was generally low, indicating that microbial communities were rarely P-limited, possibly because of the use of organic P sources. A pronounced interannual variability of degradation patterns was found, with maximum rates of protease being the highest in most of the samples, followed by the alkaline phosphatase's ones. Water column features greatly affected hydrolysis rates, being degradation of linear polysaccharides, lipids, phosphorilated compounds and polypeptides significantly different at different depths during stratified condition. Mixing processes affected especially α-glucosidase activity, possibly as a consequence of resuspension of organic matter from the seabed. Large-impact phenomena such as the 2003 heat wave and mucilage influenced the degradation of specific substrates. Mucilage enhanced lipase, phosphatase and protease, whereas a pronounced inhibition characterised phosphatase and protease

  15. METHOD OF PRODUCING DENSE CONSOLIDATED METALLIC REGULUS

    DOEpatents

    Magel, T.T.

    1959-08-11

    A methcd is presented for reducing dense metal compositions while simultaneously separating impurities from the reduced dense metal and casting the reduced parified dense metal, such as uranium, into well consolidated metal ingots. The reduction is accomplished by heating the dense metallic salt in the presence of a reducing agent, such as an alkali metal or alkaline earth metal in a bomb type reacting chamber, while applying centrifugal force on the reacting materials. Separation of the metal from the impurities is accomplished essentially by the incorporation of a constricted passageway at the vertex of a conical reacting chamber which is in direct communication with a collecting chamber. When a centrifugal force is applled to the molten metal and slag from the reduction in a direction collinear with the axis of the constricted passage, the dense molten metal is forced therethrough while the less dense slag is retained within the reaction chamber, resulting in a simultaneous separation of the reduced molten metal from the slag and a compacting of the reduced metal in a homogeneous mass.

  16. Phytoplankton temporal changes in a coastal northern Adriatic site during the last 25 years

    NASA Astrophysics Data System (ADS)

    Cabrini, Marina; Fornasaro, Daniela; Cossarini, Gianpiero; Lipizer, Marina; Virgilio, Damiano

    2012-12-01

    There is an increasing awareness of the relationships among key phytoplankton groups and their role in biogeochemical cycles; however, less is known about the temporal scales of variability in biodiversity of the phytoplankton community. In the present study a long-term data set (1986-2010) of phytoplankton abundance is used to investigate the temporal variability of the phytoplankton community at a coastal site in the Gulf of Trieste (northern Adriatic Sea). The interannual variability of the phytoplankton community shows two major periods in terms of abundance and community composition. The first one, 1986-1994, was characterized by the highest abundances of microalgae and the dominance of phytoflagellates. The second period (1995-2007) showed lower abundances and a collapse of phytoflagellates. Lastly, an apparent new increase in abundances has been recorded during recent years (2008-2010). On a seasonal scale, a classical cycle with two maxima (spring and autumn) and a summer minimum is evident. Diatoms are the most abundant group of the late winter-early spring bloom whereas phytoflagellates, the most abundant group throughout the year, dominate the late spring blooms. Dinoflagellates and coccolithophores have low abundances and show their maxima in summer and autumn, respectively. The species composition has been analysed according to the Indicator Value Index, highlighting the more frequent and abundant taxa for each month. Results show that the winter months are characterized by coccolithophores, in spring small diatoms are dominant, dinoflagellates and larger diatoms are typical in summer, and coccolithophores and diatom colonies characterise the autumn.

  17. Transport and dispersion of particulate Hg associated with a river plume in coastal Northern Adriatic environments.

    PubMed

    Covelli, Stefano; Piani, Raffaella; Acquavita, Alessandro; Predonzani, Sergio; Faganeli, Jadran

    2007-01-01

    The role of suspended particulate matter (SPM) as an important carrier of mercury (Hg) dispersed into the Gulf of Trieste and in the adjacent Grado lagoon (Northern Adriatic Sea) was studied during a high Isonzo River inflow and the resulting river plume formation. Despite the fact that extreme flood events are rare during the year, they account for most of the PHg influx (37-112 ngL(-1)) into the Gulf of Trieste. When the river plume is diverted to the SW under the influence of an E-NE wind, the tidal flux acts as a "transport belt" carrying the PHg, mostly inorganic, into the Grado lagoon. A preliminary estimation indicates that the amount of PHg entrapped in the lagoon basin following a tidal semi-cycle accounts for 1.4 kg/12h, which corresponds to about 49% of the total Hg carried by the tidal flow. These findings should be considered in future remediation strategies in the lagoon environment.

  18. Pliocene -Pleistocene geomorphological evolution of the Adriatic side of Central Italy

    NASA Astrophysics Data System (ADS)

    Gentili, Bernardino; Pambianchi, Gilberto; Aringoli, Domenico; Materazzi, Marco; Giacopetti, Marco

    2017-02-01

    This work is a significant contribution to knowledge of the Quaternary and pre-Quaternary morphogenesis of a wide sector of central Italy, from the Apennine chain to the Adriatic Sea. The goal is achieved through a careful analysis and interpretation of stratigraphic and tectonic data relating to marine and continental sediments and, mostly, through the study of relict limbs of ancient landscapes (erosional surfaces shaped by prevailing planation processes). The most important scientific datum is the definition of the time span in which the modelling of the oldest morphological element (the "summit relict surface") occurred: it started during Messinian in the westernmost portion and after a significant phase during middle-late Pliocene, ended in the early Pleistocene. During the middle and late Pleistocene, the rapid tectonic uplift of the area and the climate fluctuations favoured the deepening of the hydrographic network and the genesis of three orders of fluvial terraces, thus completing the fundamental features of the landscape. The subsequent Holocene evolution reshaped the minor elements, but not the basic ones.

  19. The Clodia database: a long time series of fishery data from the Adriatic Sea

    PubMed Central

    Mazzoldi, Carlotta; Sambo, Andrea; Riginella, Emilio

    2014-01-01

    Long-term time series of species abundances can depict population declines and changes in communities in response to anthropogenic activities, climate changes, alterations of trophic relationships. Here we present a database of historical marine fishery landing data, covering a remarkably long time series (1945–2013) and referring to one of the most exploited areas of the Mediterranean Sea, the Adriatic Sea. The database includes two time series of landing data, 1945–2013 and 1997–2013, from the official statistics of the fish market of Chioggia, where the major fishing fleet of the area operates. Comparisons between the landing data of the database and landing data from other fisheries or data from scientific surveys support the reliability of the time series in depicting changes in species abundances. The database is expected to be used by fishery biologists and ecologists interested in depicting and understanding temporal variations in species abundances and community composition, in relation to environmental and anthropogenic factors. PMID:25977775

  20. Levels of total mercury in marine organisms from Adriatic Sea, Italy.

    PubMed

    Perugini, Monia; Visciano, Pierina; Manera, Maurizio; Zaccaroni, Annalisa; Olivieri, Vincenzo; Amorena, Michele

    2009-08-01

    The presence of total mercury in fish, crustacean and cephalopod from Adriatic Sea, was investigated. The highest concentrations were observed in decreasing order in: Norway lobster (0.97 +/- 0.24 mg/kg; mean +/- SE), European hake (0.59 +/- 0.14 mg/kg), red mullet (0.48 +/- 0.09 mg/kg), blue whiting (0.38 +/- 0.09 mg/kg), Atlantic mackerel (0.36 +/- 0.08 mg/kg) and European flying squid (0.25 +/- 0.03 mg/kg). A significant difference (p < 0.01) was found between the levels of total mercury in Norway lobster and those detected in all other species. The 25% of all samples exceeded the maximum limit fixed by Commission Regulation (EC) No 1881/2006. The results show that fish and fishery products can exceed the maximum levels and stress the need of more information for consumers in particular for people that eat large amount of fish.

  1. Arsenic in Norway lobster (Nephrophs norvegicus L. ) from Kvarneric Bay - Northeastern Adriatic

    SciTech Connect

    Sekulic, B. ); Sapunar, J.; Bazulic, D. )

    1993-09-01

    Arsenic is of concern as environmental pollutant because it is a ubiquitous element known to give rise to adverse human health effects ranging from minor disorders to cancer and acute death. Arsenic occurrence in the environment depends on such human activities as coal burning, use of pesticides, glass industry, electric application, veterinary medicine, etc. It has long been known that marine fishery products may contain high levels of arsenic. Fortunately, mainly in the organic, non-toxic form, with the average proportion of organic form in total arsenic between 71-79% and 50-97%. According to Lawrence et al., arsenic in marine fish was identified as arsenobetaine and, in shrimp only, arsenocholine. This paper examines the levels of total arsenic in the sample of the muscle and hepatopancreas of female and male Norway lobster, Nephrophs norvegicus L. from the area of Kvarneric Bay, Northeastern Adriatic (Croatia). The average values of arsenic in muscle from female and male lobster were 13.26 mg (kg and 14.20. mg/kg), respectively. In hepatopancreas the values were 17.12 mg/kg and 13.34 mg/kg for female and male, respectively. 11 refs., 1 fig., 1 tab.

  2. Meteoceanographic premises for structural design purposes in the Adriatic Sea: Acquisition and processing of data

    SciTech Connect

    Rampolli, M.; Biancardi, A.; Filippi, G. De

    1996-12-31

    In 1993 the leading international standards (ISO, APOI RP2A) for the design of offshore structures drastically changed the procedure for the definition of hydrodynamic forces. In particular oil companies are required to have a detailed knowledge of the weather of the areas where they operate, if they want to maintain the previous results. Alternatively, more conservative hydrodynamic forces must be considered in the design phase. Such an increase, valuable in 20--30% of total hydrodynamic force, means heavier platform structures in new projects, and more critical elements to be inspected in existing platforms. In 1992, in order to have more reliable and safe transports to and from the platforms, Agip installed a meteo-marine sensor network in Adriatic Sea, on 13 of the over 80 producing platforms. Data collected are sent to shore via radio and operators can use real time data or 12-hour wave forecast, obtained by a statistic forecasting model. Taking advantage by such existing instruments, a project was undertaken in 1993 with the purpose of determining the extreme environmental parameters to be used by structural engineers. The network has been upgraded in order to achieve directional information of the waves and to permit short term analysis. This paper describes the data acquisition system, data processing and the achieved results.

  3. Rospo Mare (Adriatic Sea) - An oil-bearing paleokarst in the Mediterranean region

    SciTech Connect

    Soudet, H.; Sorriaux, P.; Michaud, F. )

    1990-05-01

    The oil-bearing paleokarst at Rospo Mare is located in the Adriatic Sea, 20 km off the Italian coast. The reservoir lies at a depth of 1,300 m and consists of a paleokarst of Oligocene to Miocene age that developed within Cretaceous limestones, now covered by 1,200 m of Miocene-Pliocene clastics. The oil column is about 140 m. The karstic nature of the reservoir was identified through vertical cored drill holes, which allowed us to analyze the various solution features and the sedimentary infill (speleothems, terra rossa, marine clays), as well as their vertical distribution. Observations concerning the upper part of the reservoir were compared to a paleokarst of the same age, outcropping widely onshore, in quarries located nearby. Erosion morphology at the top of the karst is highly irregular, including especially paleovalleys as well as many pit-shaped sink holes. Detailed knowledge of that morphology through geophysics helped optimizing the development of the field through horizontal drilling.

  4. Italy - Adriatic Sea - Barbara - A giant gas field marked by seismic velocity anomaly - A subtle trap

    SciTech Connect

    Ianniello, A.; Bolelli, W.; Di Scala, L. )

    1990-09-01

    Barbara gas field, discovered in 1971, is located in the northern sector of the Adriatic offshore. The field is a gentle anticline involving Quaternary clastic sediments and shaped by carbonate Mesozoic morphology. The presence of shallow gas pockets at the crest of the structure distort the seismic signal to such an extent that structural reconstruction using seismic data is not possible. Moreover, time delays and ray-path anomalies do not allow the use of staking velocities for the depth conversion. Seismic attribute analysis, instead of velocities, and time delays on the isochrone maps are providing a key to the understanding of seismic anomalies and are an indirect tool for reconstructing the real structural configuration of the field. The appraisal story of the field illustrates how the previously mentioned complications influenced its delineation and how an understanding of these complications helped in upgrading the reserves from an initial value of 10 billion ECM of gas to 40 billion ECM. Additional data acquired with the development wells tend to increase the estimate. Therefore, Barbara field is the most important Italian gas field of the decade. The producing formation is composed of very thin-bedded sandstone and shale intercalations, representing the peculiarity of this reservoir. Development of the field is being achieved with six production platforms and 72 wells.

  5. High-resolution surveys for geohazards and shallow gas: NW Adriatic (Italy) and Iskenderun Bay (Turkey)

    USGS Publications Warehouse

    Orange, D.L.; Garcia-Garcia, Ana; McConnell, D.; Lorenson, T.; Fortier, G.; Trincardi, F.; Can, E.

    2005-01-01

    The need for quantifying and understanding the distribution of shallow gas is both of academic interest and of relevance to offshore facilities. The combination of seafloor mapping, subbottom profiling, and multi-channel seismic data can provide information on regions of possible shallow gas, where the gas impacts the acoustic properties of the host material and the seafloor. In this paper, we present two case studies - one academic and one industry - that evaluate the distribution of shallow gas in two field areas in the Mediterranean. In the first case study, geophysical data from Iskenderun Bay, southeastern Turkey, indicate the presence and distribution of shallow gas. Pockmarks on the seafloor are associated with acoustic wipeout in the shallow subbottom data. Although deeper seismic data do not show bright spots or other indicators of possible gas, instantaneous frequency analysis clearly shows laterally restricted anomalies indicating gas-rich zones. The interpretation of possible shallow gas resulted in moving a proposed drilling location to a nearby area characterized by fewer (but still present) shallow gas signatures. In the second case study, cores acquired in the Po Delta, Adriatic Sea, provide quantitative ground-truthing of shallow gas - as suggested by geophysical data - and provide minimum estimates of the percentage of gas in the subsurface. Cores targeted on anomalous subbottom data yielded up to 41,000 ppm methane; cores with anomalous gas content are associated with thick recent flood deposits which may effectively isolate reactive terrigenous organic matter from biologic and physical re-working. ?? Springer 2005.

  6. Assimilation experiments for the Fishery Observing System in the Adriatic Sea

    NASA Astrophysics Data System (ADS)

    Aydoǧdu, Ali; Pinardi, Nadia; Pistoia, Jenny; Martinelli, Michela; Belardinelli, Andrea; Sparnocchia, Stefania

    2016-10-01

    An impact assessment of a Fishery Observing System (FOS) network in the Adriatic Sea was carried out with an ocean circulation model fully-coupled with a data assimilation system. The FOS data are single point vertical values of temperature collected in 2007. In this study, we used the Observing System Experiment (OSE) and Observing System Simulation Experiment (OSSE) methodologies to estimate the impact of different FOS design and sensors implementation. OSEs were conducted to evaluate real observations and they show that the FOS network improves the analysis significantly, especially during the stratification season. Root mean square (RMS) of temperature errors are reduced by about 44% and 36% in the upper and lower layers respectively. We also demonstrated that a similar impact can be obtained with a reduced number of vessels if the spatial coverage of the data points does not change significantly. In the OSSE, the impact of the implementation of a CTD (conductivity-temperature-depth) sensor in place of the existing temperature sensor was tested with identical twin approaches between January and April 2007. The results imply that the assimilation of salinity does not improve the analysis significantly during the winter and spring seasons.

  7. A process study of the Adriatic-Ionian System baroclinic dynamics

    NASA Astrophysics Data System (ADS)

    Reale, M.; Crise, A.; Farneti, R.; Mosetti, R.

    2016-08-01

    The driving mechanisms behind the decadal reversal of the Ionian Sea upper layer circulation recently sparked a considerable discussion in the Mediterranean scientific community. It has been suggested that the reversal can be driven by variations in wind stress curl over the basin, baroclinic dynamics acting within the Adriatic-Ionian System (AISys) or baroclinic dynamics driven by thermohaline properties at the AISys eastern boundary. Here we perform numerical simulations in order to assess the relative importance of remote forcings (wind stress, thermohaline fluxes, thermohaline open boundary conditions) on the vorticity and energy budget of the Ionian Sea. A mechanistic understanding of the AISys dynamics is achieved with an approach based on an increasing complexity in the model forcings and domain. Our experiments suggest that wind stress does not play a leading role in the vorticity and energy budgets of the Ionian Sea. Wind stress can reinforce or weaken the circulation but it is not able to reverse its sign. Its role becomes dominant only in the absence of inflows through the Antikythira Strait and Cretan Passage. Instead, reversals in the upper layer circulation of the Ionian Sea take place only in the presence of an active boundary on the Aegean Sea/Levantine Basin side and appear to be correlated with substantial exchanges of Availalble Potential Energy between the two basins (as observed at the end of the Eastern Mediterranean Transient). From an energetic point of view, AISys can be explained therefore only if the role of the Aegean Sea is explicitly considered.

  8. Benthic foraminifera for environmental monitoring: a case study in the central Adriatic continental shelf.

    PubMed

    Capotondi, L; Bergami, C; Orsini, G; Ravaioli, M; Colantoni, P; Galeotti, S

    2015-04-01

    A study of benthic foraminifera was carried out in sediment samples collected from the central Adriatic coast of Italy, near the Ancona harbour and the Falconara Marittima oil refinery, in order to validate and support their use as bioindicators of ecosystem quality. On the basis of a principal component analysis (PCA), three biotopes (following the bathymetric gradient) have been documented, showing that the distribution pattern of benthic foraminifera is principally related to riverine inputs, organic matter contents at the seafloor, and sediment grain size. We observed higher abundances of opportunistic, low-oxygen tolerant taxa along the coastline, thus being representative of polluted environmental conditions. Near the Falconara Marittima oil refinery, the microfaunal assemblages is characterized by the absence of living specimens and by a low diversity associated with the dominance of opportunistic species. At this site, aberrant tests were also found. The data point out that Ammonia parkinsoniana and Quinqueloculina seem to be the most sensitive taxa and can be considered as good bioindicators of environmental stress in this area. This study confirms that faunal composition and morphology of benthic foraminifera respond to human-induced environmental perturbations, making their study potentially useful for biomonitoring in coastal-marine areas.

  9. Genetic diversity of Arcobacter isolated from bivalves of Adriatic and their interactions with Mytilus galloprovincialis hemocytes.

    PubMed

    Ottaviani, Donatella; Mosca, Francesco; Chierichetti, Serena; Tiscar, Pietro Giorgio; Leoni, Francesca

    2017-02-01

    The human food-borne pathogens Arcobacter butzleri and A. cryaerophilus have been frequently isolated from the intestinal tracts and fecal samples of different farm animals and, after excretion, these microorganisms can contaminate the environment, including the aquatic one. In this regard, A. butzleri and A. cryaerophilus have been detected in seawater and bivalves of coastal areas which are affected by fecal contamination. The capability of bivalve hemocytes to interact with bacteria has been proposed as the main factor inversely conditioning their persistence in the bivalve. In this study, 12 strains of Arcobacter spp. were isolated between January and May 2013 from bivalves of Central Adriatic Sea of Italy in order to examine their genetic diversity as well as in vitro interactions with bivalve components of the immune response, such as hemocytes. Of these, seven isolates were A. butzleri and five A. cryaerophilus, and were genetically different. All strains showed ability to induce spreading and respiratory burst of Mytilus galloprovincialis hemocytes. Overall, our data demonstrate the high genetic diversity of these microorganisms circulating in the marine study area. Moreover, the Arcobacter-bivalve interaction suggests that they do not have a potential to persist in the tissues of M. galloprovincialis.

  10. Eastern Mediterranean high resolution paleoclimate investigations using south Adriatic finely laminated sediment: preliminary data

    NASA Astrophysics Data System (ADS)

    Goudeau, Marie-Louise; Robert, Brice; Jilbert, Tom; Fhlaithearta, Shauna Ni; Zonneveld, K. A. F.; Versteegh, G. J. M.; Grauel, A.; Bernasconi, S.; de Lange, G. J.

    2010-05-01

    The formation of distinct organic-rich units (sapropels) in the Medditerenean is well-known, and intensively studied , however less is known of the smaller scale variability during their formation. Multicore GeoB 107-39-03 was taken in 2006, in the central part of the straits of Otranto, south Adriatic. Over the main part of the core, fine, sub-milimetric scale laminae are found. Preliminary dating indicates a Sapropel 1 age for these sediments. The fine, laminae permit high-resolution climate variability to be studied in this area during sapropel formation. Besides conventional geochemical analyses on discrete samples (XRF, ICP-OES, organic C/N, 13C) a novel technique was used to investigate the sediment chemistry at the laminae scale: the sediment has been resin-impregnated to enable laser ablation coupled to ICP-MS analyses (LA-ICP-MS). This method recently developed (Jilbert et al., 2008) permits extremely high resolution geochemical profiling of the laminated sediment, to unravel the forcing mechanisms generating the laminae. Furthermore, in order to compare the data to modern sediment geochemistry, a series of analyses were carried out on a batch of sediment surface samples in collaboration with the MOCCHA project partners (see Posters/Talks in session OS15). This work is supported by the EUROCORES/EUROMARC Program of the European Science Foundation (NWO.817.01.002 MOCCHA project).

  11. PAH content, toxicity and genotoxicity of coastal marine sediments from the Rovinj area, Northern Adriatic, Croatia.

    PubMed

    Bihari, Nevenka; Fafandel, Maja; Hamer, Bojan; Kralj-Bilen, Blanka

    2006-08-01

    Surface marine sediments collected from 8 sampling sites within the Rovinj coastal area, Northern Adriatic, Croatia, were used for determining priority pollutant polycyclic aromatic hydrocarbons (PAHs) and toxic/genotoxic potential of sediment organic extracts. Total PAH concentrations ranged from 32 microg/kg (protected area) to 13.2 mg/kg dry weight (harbor) and showed clear differences between pristine, urban industrial and harbor areas. PAHs distribution revealed their pyrogenic origin with some biogenic influence in harbor. At all sampling sites sediment extracts showed toxic potential that was consistent with the sediment type. No correlation between toxicity measured by Microtox assay and concentrations of individual or total PAHs was found. Noncytotoxic dose of sediment extracts showed no genotoxic potential in bacterial umu-test. DNA damage is positively related to total PAHs at 4 sampling sites (S-1, S-2, S-3, S-6), but the highest DNA damage was not observed at the site with the highest total sediment PAH content (S-5).

  12. Hydromorphic to subaqueous soils transitions in the central Grado lagoon (Northern Adriatic Sea, Italy)

    NASA Astrophysics Data System (ADS)

    Vittori Antisari, Livia; De Nobili, Maria; Ferronato, Chiara; Natale, Marco; Pellegrini, Elisa; Vianello, Gilmo

    2016-05-01

    The Grado lagoon is among the largest in the Mediterranean sea and is characterized by salt marshes, where tides influenced the development of a complex micromorphology coupled to a micromosaic of vegetation covers. This study represents the first contribution to the understanding of the main processes governing formation, development and spatial transitions between hydromorphic and subaqueous soils in an Adriatic lagoon ecosystem. Physicochemical characteristics and development of soils were investigated in three salt marshes differing for their proximity to the open sea, textural composition and age of formation. Soils of back barrier salt marshes had A/C profiles and were mostly characterized by a sandy coarse texture that allows rapid drainage and subsurface oxygen exchanges. Soil sequences from the inner salt marsh to its submerged border slope or to a brackish waterhole do not simply represent a hydrosequence, but also reflect erosion/sorting/accumulation processes. The soils in the central part of the lagoon have finer texture and in displayed transition or cambic horizons. Silty clay loam textures and low positions allowed the development of more severe anoxic conditions and accumulation of sulphides. The tide oscillation strongly contributed to formation of redoximorphic features, intensity of anaerobic conditions but also colonization by different plant communities. Discriminant analysis was performed to identify physicochemical properties which discriminate the different soils according to geo-morphological position and prevailing plants. It confirmed that differentiation of plant communities occurred according to distinct morphological and physicochemical soil properties, but also acted as a primary affecting factor of pedogenesis.

  13. Measurements and modeling of the volume scattering function in the coastal northern Adriatic Sea

    NASA Astrophysics Data System (ADS)

    Berthon, Jean-François; Shybanov, Eugeny; Lee, Michael E.-G.; Zibordi, Giuseppe

    2007-08-01

    We performed measurements of the volume scattering function (VSF) between 0.5° and 179° with an angular resolution of 0.3° in the northern Adriatic Sea onboard an oceanographic platform during three different seasons, using the multispectral volume scattering meter (MVSM) instrument. We observed important differences with respect to Petzold's commonly used functions, whereas the Fournier-Forand's analytical formulation provided a rather good description of the measured VSF. The comparison of the derived scattering, bp(λ) and backscattering, bbp(λ) coefficients for particles with the measurements performed with the classical AC-9 and Hydroscat-6 showed agreement to within 20%. The use of an empirical relationship for the derivation of bb(λ) from β(ψ,λ) at ψ=140° was validated for this coastal site although ψ=118° was confirmed to be the most appropriate angle. The low value of the factor used to convert β(ψ,λ) into bb(λ) within the Hydroscat-6 processing partially contributed to the underestimation of bb(λ) with respect to the MVSM. Finally, use of the Kopelevich model together with a measurement of bp(λ) at λ=555 nm allowed us to reconstruct the VSF with average rms percent differences between 8 and 15%.

  14. Lead and cadmium content in human milk from the Northern Adriatic area of Croatia

    SciTech Connect

    Frkovic, A.; Kras, M.; Alebic-Juretic, A.

    1997-01-01

    Though occupational exposure to toxic metals (lead, cadmium) is well documented, harmful effects of environmental exposure to lower levels of these two metals is still under investigation. Most toxic metals are emitted by human activities and the atmosphere is the main transport route for these elements. According to some authors, 332 358 t of lead and 7570 t of cadmium were emitted in the atmosphere from anthropogenic sources in 1983. The principle source of lead is traffic, e.g. leaded petrol, still widely used in Croatia, as well as coal combustion, iron and steal production. Volcanic activity, zinc production and waste incineration are the main sources of cadmium. Recent study indicates that traffic could also be the main source of cadmium found along busy streets. Chronic lead exposure at low levels is associated with adverse health effects especially in fetus and young children. This study examines lead and cadmium levels in breast milk from nursing women living in the Northern Adriatic area of Croatia. 15 refs., 2 tabs.

  15. Evolution of Dense Gas with Starburst Age: When Star Formation Versus Dense Gas Relations Break Down

    NASA Astrophysics Data System (ADS)

    Meier, David S.; Turner, J. L.; Schinnerer, E.

    2011-05-01

    Dense gas correlates well with star formation on kpc scales. On smaller scales, motions of individual clouds become comparable to the 100 Myr ages of starbursts. One then expects the star formation rate vs. dense gas relations to break down on giant molecular cloud scales. We exploit this to study the evolutionary history of nuclear starburst in the nearby spiral, IC 342. Maps of the J=5-4 and 16-15 transitions of dense gas tracer HC3N at 20 pc resolution made with the VLA and the Plateau de Bure interferometer are presented. The 5-4 line of HC3N traces very dense gas in the cold phase, while the 16-15 transition traces warm, dense gas. These reveal changes in dense cloud structure on scales of 30 pc among clouds with star formation histories differing by only a few Myrs. HC3N emission does not correlate well with young star formation at these high spatial resolutions, but gas excitation does. The cold, dense gas extends well beyond the starburst region implying large amounts of dense quiescent gas not yet actively forming stars. Close to the starburst the high excitation combined with faint emission indicates that the immediate (30 pc) vicinity of the starburst lacks large masses of very dense gas and has high dense gas star formation efficiencies. The dense gas appears to be in pressure equilibrium with the starburst. We propose a scenario where the starburst is being caught in the act of dispersing or destroying the dense gas in the presence of the expanding HII region. This work is supported by the NSF through NRAO and grant AST-1009620.

  16. Long-term fluctuations in Cystoseira populations along the west Istrian Coast (Croatia) related to eutrophication patterns in the northern Adriatic Sea.

    PubMed

    Iveša, Ljiljana; Djakovac, Tamara; Devescovi, Massimo

    2016-05-15

    An exploration of historical data suggested that eutrophication patterns might drive long-term fluctuations in Cystoseira populations along the west Istrian Coast (northern Adriatic Sea, Croatia). The regimes of northern Italian rivers, which flow approximately 100km west of the study area, mainly modulate the eutrophication levels of the northern Adriatic Sea. A regression of Cystoseira populations from the 1970s through the 1990s corresponded to increased levels of eutrophication in the study area. During the late 1990s, the density of sea urchins, which are efficacious macroalgal predators, decreased, likely due to an intense formation of pelagic mucilage aggregates that resulted in mass mortality episodes of macrozoobenthic species. During the 2000-2013 period, an oligotrophication of the northern Adriatic formed the basis for the recovery of Cystoseira taxa, whose abundances from 2009 to 2013 were similar to those characterising the most flourishing Mediterranean Cystoseira assemblages.

  17. Towards an operational use of space imagery for oil pollution monitoring in the Mediterranean basin: a demonstration in the Adriatic Sea.

    PubMed

    Ferraro, Guido; Bernardini, Annalia; David, Matej; Meyer-Roux, Serge; Muellenhoff, Oliver; Perkovic, Marko; Tarchi, Dario; Topouzelis, Kostas

    2007-04-01

    Studies of operational pollution carried out by European commission - Joint Research Centre in the Mediterranean Sea for the years 1999-2004 are briefly introduced. The specific analysis of the Adriatic Sea for the same period demonstrates that this area has been characterized by a relevant number of illegal discharges from ships. After setting the historical background of the project AESOP (aerial and satellite surveillance of operational pollution in the Adriatic Sea), the content, partners and aim of the project are presented. Finally, the results of the first phase of the AESOP project are presented. The results seem very encouraging. For the first time in the Adriatic, real time detection of oil spills in satellite images and an immediate verification by the Coast Guard has been undertaken. An exploratory activity has also been carried out in collaboration with the University of Ljubljana to use automatic information system (AIS) to identify the ships detected in the satellite images.

  18. ADCP observations about the mean stratification and the vertical structure of tidal and inertial currents in the northern Adriatic

    NASA Astrophysics Data System (ADS)

    Fuda, J.-L.; Millot, C.

    2003-04-01

    Mounted on the GEOSTAR benthic observatory (Beranzoli et al., 2000) which was deployed in August 1998 at about 42 m in the northern Adriatic for test purposes, a 300-kHz ADCP was operated during 18 days with an hourly sampling rate. The reduced cell size of 80 cm allowed to study finely i) the temporal variation of the mean stratification, ii) the vertical structure of tidal currents and iii) an energetic few-day episode of inertial oscillations. Even though no thermistor string was available to monitor the stratification's evolution, the maximum magnitude of the current shear was found to be a relevant indicator of the pycnocline's depth, as confirmed by ship-handled CTD profiles performed just before and after the experiment. From the depth evolution of the shear maximum, it was possible to detect a sudden deepening of the pycnocline (from about 14 m down to about 30 m), consistently with simultaneous temperature and salinity increases recorded by an observatory-mounted SBE16 CTD. Such a deepening might be attributed to the advection of a neighbouring thicker mixed layer, to an intense vertical mixing due to sea roughness or, more probably, to a downwelling phenomenon. Indeed, it was associated with south-easterly winds that prevailed in the northern Adriatic and with downward vertical velocities (1-2 cm/s) that were sampled over the whole depth during the pycnocline's deepening. Rotary spectral analysis and band-pass filtering at all depths in the inertial, diurnal and semi-diurnal frequency bands revealed the complex vertical structure of the related currents. This is particularly striking for the diurnal components whose energy is confined in a few-meter surface layer, contrary to the energy of the semidiurnal components which is distributed over the whole water column. Concerning the former (K1 mainly), the tidal harmonic analysis (Foreman, 1978) evidences a clockwise polarisation of the currents and a roughly constant orientation of the related ellipses

  19. Measuring Wind Ventilation of Dense Surface Snow

    NASA Astrophysics Data System (ADS)

    Drake, S. A.; Huwald, H.; Selker, J. S.; Higgins, C. W.; Lehning, M.; Thomas, C. K.

    2014-12-01

    Wind ventilation enhances exposure of suspended, canopy-captured and corniced snow to subsaturated air and can significantly increase sublimation rate. Although sublimation rate may be high for highly ventilated snow this snow regime represents a small fraction snow that resides in a basin potentially minimizing its influence on snow mass balance. In contrast, the vast majority of a seasonal snowpack typically resides as poorly ventilated surface snow. The sublimation rate of surface snow is often locally so small as to defy direct measurement but regionally pervasive enough that the integrated mass loss of frozen water across a basin may be significant on a seasonal basis. In a warming climate, sublimation rate increases even in subfreezing conditions because the equilibrium water vapor pressure over ice increases exponentially with temperature. To better understand the process of wintertime surface snow sublimation we need to quantify the depth to which turbulent and topographically driven pressure perturbations effect air exchange within the snowpack. Hypothetically, this active layer depth increases the effective ventilated snow surface area, enhancing sublimation above that given by a plane, impermeable snow surface. We designed and performed a novel set of field experiments at two sites in the Oregon Cascades during the 2014 winter season to examine the spectral attenuation of pressure perturbations with depth for dense snow as a function of turbulence intensity and snow permeability. We mounted a Campbell Scientific Irgason Integrated CO2 and H2O Open Path Gas Analyzer and 3-D Sonic Anemometer one meter above the snow to capture mean and turbulent wind forcing and placed outlets of four high precision ParoScientific 216B-102 pressure transducers at different depths to measure the depth-dependent pressure response to wind forcing. A GPS antenna captured data acquisition time with sufficient precision to synchronize a Campbell Scientific CR-3000 acquiring

  20. Gel trapping of dense colloids.

    PubMed

    Laxton, Peter B; Berg, John C

    2005-05-01

    Phase density differences in sols, foams, or emulsions often lead to sedimentation or creaming, causing problems for materials where spatial uniformity over extended periods of time is essential. The problem may be addressed through the use of rheology modifiers in the continuous phase. Weak polymer gels have found use for this purpose in the food industry where they appear to be capable of trapping dispersoid particles in a three-dimensional matrix while displaying water-like viscosities at low shear. Attempts to predict sedimentation stability in terms of particle properties (size, shape, density difference) and gel yield stress have led to qualitative success for suspensions of large particles. The effect of particle size, however, in particular the case in which colloidal dimensions are approached, has not been investigated. The present work seeks to determine useful stability criteria for colloidal dispersions in terms of readily accessible viscoelastic descriptors. Results are reported for systems consisting of 12 microm poly(methyl methacrylate) (PMMA) spheres dispersed in aqueous gellan gum. Monovalent salt concentration is varied to control rheological properties, and sedimentation/centrifugation experiments are performed to determine dispersion stability. Necessary conditions for stability consist of a minimum yield stress together with a value of tan delta less than unity.

  1. Assessing the main threats to marine ecosystem components of the Adriatic - Ionian Region for the implementation of Maritime Spatial Planning

    NASA Astrophysics Data System (ADS)

    Lipizer, Marina

    2015-04-01

    Marine and coastal ecosystems and the related benefits they provide for humans are threatened by increasing pressures and competing usages. To address these issues, in the last decade, several EU legislations have been formulated to guarantee and promote sustainable use of the sea (e.g. Common Fishery Policy, Marine Strategy Framework Directive, Maritime Spatial Planning). As a first step to implement cross-border Maritime Spatial Planning (MSP) in the Adriatic - Ionian Seas, a review of the main anthropogenic pressures due to maritime activities involving the Adriatic - Ionian Region (AIR) as well as of the most relevant environmental components has been carried out. The main objective of the analysis is to better identify the spatial distribution of human uses of the sea and of the key environmental components and the ecosystem services provided. The analysis of the existing conditions includes a description of the human activities per economic sector, considering type, location, dimension and magnitude of the activity in the AIR and the spatial extent of the main environmental and ecological values present in the AIR. The environmental status has been characterized according to the descriptors proposed by the Marine Strategy Framework Directive (MSFD Directive 2008/56/EC) and the most sensitive ecosystem components in the AIR have been pointed out. A qualitative analysis of the relationships between good environmental status descriptors sensu MSFD and ecosystem services in the AIR has been carried out to provide useful information for the implementation of MSP. Cross-border Maritime Spatial Planning is particularly needed in a semi-enclosed basin such as the Adriatic Sea, hosting very diverse human activities, ranging from fishery to tourism, sand extraction, commercial and passenger transport, oil and gas exploration and exploitation, which may partially overlap and severely threaten ecosystem functioning and the associated services.

  2. Age modelling of late Quaternary marine sequences in the Adriatic: Towards improved precision and accuracy using volcanic event stratigraphy

    NASA Astrophysics Data System (ADS)

    Lowe, J. J.; Blockley, S.; Trincardi, F.; Asioli, A.; Cattaneo, A.; Matthews, I. P.; Pollard, M.; Wulf, S.

    2007-02-01

    The first part of this paper presents a review of the problems that constrain the reliability of radiocarbon-based age models with particular focus on those used to underpin marine records. The reasons why radiocarbon data-sets need to be much more comprehensive than has been the norm hitherto, and why age models should be based on calibrated data only, are outlined. The complexity of the probability structure of calibrated radiocarbon data and the advantages of a Bayesian statistical approach for constructing calibrated age models are illustrated. The second part of the paper tests the potential for reducing the uncertainties that constrain radiocarbon-based age models using tephrostratigraphy. Fine (distal) ash layers of Holocene age preserved in Adriatic prodelta sediments are analysed geochemically and compared to tephras preserved in the Lago Grande di Monticchio site in southern Italy. The Monticchio tephras have been dated both by radiocarbon and varve chronology. The importance of basing such comparisons on standardised geochemical and robust statistical procedures is stressed. In this instance, both the Adriatic and Monticchio geochemical measurements are based on wavelength dispersive spectrometry, while discriminant function analysis is employed for statistical comparisons. Using this approach, the ages of some of the Adriatic marine ash layers could be estimated in Monticchio varve years, circumventing some of the uncertainty of radiocarbon-based age models introduced by marine reservoir effects. Fine (distal) ash layers are more widespread and better preserved in Mediterranean marine sequences than realised hitherto and may offer much wider potential for refining the dating and correlation of Mediterranean marine sequences as well as marine-land correlations.

  3. Computed and observed turbulent heat fluxes during an extreme Bora event in the Adriatic using atmosphere-ocean coupling

    NASA Astrophysics Data System (ADS)

    Ličer, Matjaž; Smerkol, Peter; Fettich, Anja; Ravdas, Michalis; Papapostolou, Alexandros; Mantziafou, Anneta; Strajnar, Benedikt; Cedilnik, Jure; Jeromel, Maja; Jerman, Jure; Petan, Sašo; Benetazzo, Alvise; Carniel, Sandro; Malačič, Vlado; Sofianos, Sarantis

    2016-04-01

    We have studied the performances of (a) a two-way coupled atmosphere-ocean modeling system and (b) one-way coupled ocean model (forced by the atmosphere model), as compared to the available in situ measurements during and after a strong Adriatic Bora wind event in February 2012, which led to extreme air-sea interactions. The simulations span the period between January and March 2012. The models used were ALADIN (4.4 km resolution) on the atmosphere side and Adriatic setup of POM (1°/30 × 1°/30 angular resolution) on the ocean side. The atmosphere-ocean coupling was implemented using the OASIS3-MCT model coupling toolkit. Two-way coupling ocean feedback to the atmosphere is limited to sea surface temperature. We have compared modeled atmosphere-ocean fluxes (computed using modified Louis scheme) and sea temperatures from both setups to platform and CTD measurements of fluxes (computed using COARE scheme) and temperatures from three observational platforms (Vida, Paloma, Acqua Alta) in the Northern Adriatic. We show that turbulent fluxes from both setups differ up to 20% during the Bora but not significantly before and after the event. The impact of the coupling on the ocean is significant while the impact on the atmosphere is less pronounced. When compared to observations, two way coupling ocean temperatures exhibit a four times lower RMSE than those from one-way coupled system. Two-way coupling improves sensible heat fluxes at all stations but does not improve latent heat loss.

  4. Occurrence of the Leech, Pontobdella muricata Linnaeus, on Elasmobranch Species in the Northern and Central Adriatic Sea.

    PubMed

    Bolognini, Luca; Leoni, Simone; Polidori, Piero; Grati, Fabio; Scarcella, Giuseppe; Pellini, Giulio; Domenichetti, Filippo; Ferrà, Carmen; Fabi, Gianna

    2016-12-01

    This study provides a parasitological analysis of the elasmobranch species caught in the northern and central Adriatic Sea. Sixty-two marine leeches were recorded on 747 individuals of Raja clavata Linnaeus, 1758 (thornback ray), Myliobatis aquila Linnaeus, 1758 (common eagle ray), and Torpedo marmorata Risso, 1810 (marbled torpedo ray) caught in 56 hauls over a 5 yr period. All leeches were identified as Pontobdella muricata, which is a typical ectoparasite of benthic elasmobranchs. The prevalence of infection ranged from 7.11% on R. clavata to 12.00% on M. aquila. The intensity of infection, the preferential sites of attachment to the host, and the periodicity of infection were evaluated.

  5. Molecular defects that affect platelet dense granules.

    PubMed

    Gunay-Aygun, Meral; Huizing, Marjan; Gahl, William A

    2004-10-01

    Platelet dense granules form using mechanisms shared by melanosomes in melanocytes and by subsets of lysosomes in more generalized cells. Consequently, disorders of platelet dense granules can reveal how organelles form and move within cells. Models for the study of new vesicle formation include isolated delta-storage pool deficiency, combined alphadelta-storage pool deficiency, Hermansky-Pudlak syndrome (HPS), Chediak-Higashi syndrome, Griscelli syndrome, thrombocytopenia absent radii syndrome, and Wiskott-Aldrich syndrome. The molecular bases of dense granule deficiency are known for the seven subtypes of HPS, as well as for Chediak-Higashi syndrome, Griscelli syndrome, and Wiskott-Aldrich syndrome. The gene products involved in these disorders help elucidate the generalized process of the formation of vesicles from extant membranes such as the Golgi.

  6. Coalescence preference in densely packed microbubbles

    SciTech Connect

    Kim, Yeseul; Lim, Su Jin; Gim, Bopil; Weon, Byung Mook

    2015-01-13

    A bubble merged from two parent bubbles with different size tends to be placed closer to the larger parent. This phenomenon is known as the coalescence preference. Here we demonstrate that the coalescence preference can be blocked inside a densely packed cluster of bubbles. We utilized high-speed high-resolution X-ray microscopy to clearly visualize individual coalescence events inside densely packed microbubbles with a local packing fraction of ~40%. Thus, the surface energy release theory predicts an exponent of 5 in a relation between the relative coalescence position and the parent size ratio, whereas our observation for coalescence in densely packed microbubbles shows a different exponent of 2. We believe that this result would be important to understand the reality of coalescence dynamics in a variety of packing situations of soft matter.

  7. Coalescence preference in densely packed microbubbles

    DOE PAGES

    Kim, Yeseul; Lim, Su Jin; Gim, Bopil; ...

    2015-01-13

    A bubble merged from two parent bubbles with different size tends to be placed closer to the larger parent. This phenomenon is known as the coalescence preference. Here we demonstrate that the coalescence preference can be blocked inside a densely packed cluster of bubbles. We utilized high-speed high-resolution X-ray microscopy to clearly visualize individual coalescence events inside densely packed microbubbles with a local packing fraction of ~40%. Thus, the surface energy release theory predicts an exponent of 5 in a relation between the relative coalescence position and the parent size ratio, whereas our observation for coalescence in densely packed microbubblesmore » shows a different exponent of 2. We believe that this result would be important to understand the reality of coalescence dynamics in a variety of packing situations of soft matter.« less

  8. IR Spectroscopy of PAHs in Dense Clouds

    NASA Astrophysics Data System (ADS)

    Allamandola, Louis; Bernstein, Max; Mattioda, Andrew; Sandford, Scott

    2007-05-01

    Interstellar PAHs are likely to be a component of the ice mantles that form on dust grains in dense molecular clouds. PAHs frozen in grain mantles will produce IR absorption bands, not IR emission features. A couple of very weak absorption features in ground based spectra of a few objects embedded in dense clouds may be due to PAHs. Additionally spaceborne observations in the 5 to 8 ?m region, the region in which PAH spectroscopy is rich, reveal unidentified new bands and significant variation from object to object. It has not been possible to properly evaluate the contribution of PAH bands to these IR observations because the laboratory absorption spectra of PAHs condensed in realistic interstellar mixed-molecular ice analogs is lacking. This experimental data is necessary to interpret observations because, in ice mantles, the interaction of PAHs with the surrounding molecules effects PAH IR band positions, widths, profiles, and intrinsic strengths. Furthermore, PAHs are readily ionized in pure H2O ice, further altering the PAH spectrum. This laboratory proposal aims to remedy the situation by studying the IR spectroscopy of PAHs frozen in laboratory ice analogs that realistically reflect the composition of the interstellar ices observed in dense clouds. The purpose is to provide laboratory spectra which can be used to interpret IR observations. We will measure the spectra of these mixed molecular ices containing PAHs before and after ionization and determine the intrinsic band strengths of neutral and ionized PAHs in these ice analogs. This will enable a quantitative assessment of the role that PAHs can play in determining the 5-8 ?m spectrum of dense clouds and will directly address the following two fundamental questions associated with dense cloud spectroscopy and chemistry: 1- Can PAHs be detected in dense clouds? 2- Are PAH ions components of interstellar ice?

  9. Water

    MedlinePlus

    ... www.girlshealth.gov/ Home Nutrition Nutrition basics Water Water Did you know that water makes up more ... to drink more water Other drinks How much water do you need? top Water is very important, ...

  10. Quality control of climatological time series in the province of macerata (adriatic side of central italy)

    NASA Astrophysics Data System (ADS)

    Gentilucci, Matteo; Bisci, Carlo; Fazzini, Massimiliano; Tognetti, Danilo

    2016-04-01

    The analysis is focused on more than 100 meteorological recording stations located in the Province of Macerata (Marche region, Adriatic side of Central Italy) and in its neighbours; it aims to check the time series of their climatological data (temperatures and precipitations), covering about one century of observations, in order to remove or rectify any errors. This small area (about 2.800Km2) features many different climate types, because of its varied topography ranging, moving westward, from the Adriatic coast to the Appennines (over 2.100m of altitude). In this irregular context, it is difficult to establish a common procedure for each sector; therefore, it has been followed the general guidelines of the WMO, with some important difference (mostly in the method). Data are classified on the basis of validation codes (VC): missing datum (VC=-1), correct or verified datum (VC=0), datum under investigation (VC=1), datum removed after the analysis (VC=2), datum reconstructed through interpolation or by estimating the errors of digitization (VC=3). The first step was the "Logical Control", consisting in the investigation of gross errors of digitization: the data found in this phase of the analysis has been removed without any other control (VC=2). The second step, represented by the "Internal Consistency Check", leads to the elimination (VC=2) of all the data out of range, estimated on the basis of the climate zone for each investigated variable. The third one is the "Tolerance Test", carried out comparing each datum with the historical record it belongs to, in order to apply this test, the normal distribution of data has been evaluated. The "Tolerance Test" usually defines only suspect data (VC=1) to be verified with further tests, such as the "Temporal Consistency" and the "Spatial Consistency". The "Temporal Consistency" allows an evaluation of the time sequence of data, setting a specified range for each station basing upon its historical records. Data out of

  11. Crustal section based on CROP seismic data across the North Tyrrhenian Northern Apennines Adriatic Sea

    NASA Astrophysics Data System (ADS)

    Finetti, I. R.; Boccaletti, M.; Bonini, M.; Del Ben, A.; Geletti, R.; Pipan, M.; Sani, F.

    2001-12-01

    Using deep seismic reflection data from the Italian lithospheric exploration project CROP in the Central Mediterranean region, a 400-km-long section, composed of three different profiles crossing the Northern Tyrrhenian Sea (CROP M-12A profile), the Northern Apennines (CROP-03) and the Adriatic Sea (CROP M-16) is reconstructed and discussed. New data allow us to outline a seismically consistent tectono-stratigraphic setting for the crust and upper mantle of the Northern Apennines thrust-belt system and its Adriatic foreland. Time-space analysis of the deformation of the investigated chain and identification of existing macrostratigraphic crustal intervals and tectonic units allow a reasonably controlled interpretation of the geodynamic evolution and of the main orogenic stages. Careful seismic reprocessing and application of advanced techniques to key zones of the explored area (such as the Tuscan Archipelago) were determinants in obtaining fundamental information for understanding of the complex lithospheric structures and their evolution. Profile interpretation supports that the Northern Apennine chain is dominated by a compressive thrust system. Crustal extension, assumed by some authors as the dominating tectonic process for the whole Tuscan Apennine area, represents a subordinate geodynamic event of the last stage (Tyrrhenian). In the Early Cretaceous-Late Jurassic, the paleogeographic framework consisted of the Europe and Adria plates separated by the Alpine Tethys Ocean. During the Late Cretaceous-Early Eocene, Adria-Europe convergence (eo-Alpine stage) and subduction beneath the Adria plate closed the Alpine Tethys Sea, with the Tethyan slab being clearly seismically imaged. The first Apenninic geodynamic stage occurred in the Late Oligocene-Early Miocene with the opening of the Balearic Basin, which generated a first "lithospheric root" of the Apenninic chain in the Tuscan Archipelago area. This root is represented by Adria-verging thrust faults that

  12. Fast temperature relaxation model in dense plasmas

    NASA Astrophysics Data System (ADS)

    Faussurier, Gérald; Blancard, Christophe

    2017-01-01

    We present a fast model to calculate the temperature-relaxation rates in dense plasmas. The electron-ion interaction-potential is calculated by combining a Yukawa approach and a finite-temperature Thomas-Fermi model. We include the internal energy as well as the excess energy of ions using the QEOS model. Comparison