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Sample records for sea norwegian sea

  1. Permian of Norwegian-Greenland sea margins: future exploration target

    SciTech Connect

    Surlyk, F.; Hurst, J.M.; Piasecki, S.; Rolle, F.; Stemmerik, L.; Thomsen, E.; Wrang, P.

    1984-09-01

    Oil and gas exploration in the northern North Sea and the southern Norwegian shelf has mainy been concentrated on Jurassic and younger reservoirs with Late Jurassic black shale source rocks. New onshore investigations in Jameson Land, central East Greenland, suggest that the Permian of the Norwegian-Greenland Sea margins contains relatively thick sequences of potential oil source rocks interbedded with carbonate reefs. The East Greenland, Upper Permian marine basin is exposed over a length of 400 km (250 mi) from Jameson Land in the south to Wollaston Forland in the north, parallel with the continental margin. The Upper Permian black shale is relatively thick, widely distributed, has a high organic carbon content, and a favorable kerogen type. Consequently, the possibilities for a Permian play in the northern part of the Norwegian shelf and along parts of the Norwegian-Greenland Sea margins are worth evaluating.

  2. Deepwater cementing in the Norwegian Sea: A case study

    SciTech Connect

    Helgesen, J.T.; Harestad, K.; Sorgaard, E.

    1999-04-01

    During Norway`s 15th licensing round in 1996, five deepwater areas were opened for exploration drilling. All blocks are situated outside the continental shelf in the Norwegian Sea, west of mid-Norway. The seabed and location conditions were studied by the Norwegian Deepwater Project, a joint venture of the operator companies who were awarded blocks in these new unexplored areas. Results of the study revealed that the weather and sea conditions in these remote areas would be among the toughest in the world. Strong return currents from the Arctic Ocean bring undercooled water to these locations, lowering the seabed temperature to as low as {minus}2 C. Because all the blocks are situated outside the Norwegian continental shelf, the water depth is in the range of 2,600--5,000 ft (800--1,600 m). Typical deepwater conditions are present in most of the deepwater locations in the Norwegian Sea. The conditions that posed additional challenges to the drilling operation were poorly consolidated sediments, shallow water flow zones, hydrate destabilization and ooze sediments. The paper describes sediment consolidation, shallow water flow, hydrates, development of deepwater cement slurries, a field case, and future cementing operations in Norway.

  3. Inter-annual to decadal sea level variability along the Norwegian coast and in the Siberian Seas; a link with the Eastern North Atlantic

    NASA Astrophysics Data System (ADS)

    Calafat, F. M.; Chambers, D. P.

    2012-12-01

    Inter-annual to decadal sea level variations from tide gauge records along the Norwegian coast and in the Siberian Seas are examined for the period 1950 to present. A combination of observations and theory is used to explore the physical mechanisms responsible for the observed sea level variability. Tide gauge records are first grouped into 6 geographical regions: the Norwegian Coast, the Barents Sea, the Kara Sea, the Laptev Sea, the East Siberian Sea, and the Chukchi Sea. Then an average of sea level at tide gauges is computed for each region. All regions exhibit large decadal sea level variations (up to 20 cm). Sea level corrected for the inverse barometer effect is significantly correlated with the Arctic Oscillation index in all regions except in the East Siberian and Chukchi Seas. There is a coherent sea level signal that affects a region extending from Southwest Norway to the Kara Sea. Previous studies have found that sea level variability at the Norwegian coast is related to variations in the Norwegian Atlantic Current (NwAC), which are mainly driven by changes in the wind forcing over the region. Here we show that, apart from the contribution of the NwAC and the local wind, there is an additional contribution to the sea level variability at the Norwegian coast resulting from the poleward propagation of wind-driven sea level variations along the continental slope of the Northeast Atlantic. The fact that sea level variability in both the Barents and the Kara Seas is highly coherent with that in the Norwegian coast suggests propagation of sea level variations further north into these regions. Eastward of the Kara Sea, where the continental shelf is shallower, sea level variations are much larger than in the other regions and they are highly correlated (~0.75) with the local longshore wind.he average of sea level at 8 tide gauge stations on the Norwegian coast (black line) and a reconstruction of sea level (blue line) using a combination of the tide gauge at Newlyn (on the eastern boundary of the North Atlantic) and the longshore wind over the Faroe-Shetland channel and the Norwegian continental shelf. The grey shaded area represents the uncertainty of the time series. A 2-year running mean has been applied to both time series.

  4. Ecosystem structure and resilience—A comparison between the Norwegian and the Barents Sea

    NASA Astrophysics Data System (ADS)

    Yaragina, Natalia A.; Dolgov, Andrey V.

    2009-10-01

    Abundance and biomass of the most important fish species inhabited the Barents and Norwegian Sea ecosystems have shown considerable fluctuations over the last decades. These fluctuations connected with fishing pressure resulted in the trophic structure alterations of the ecosystems. Resilience and other theoretical concepts (top-down, wasp-waste and bottom-up control, trophic cascades) were viewed to examine different response of the Norwegian and Barents Sea ecosystems on disturbing forces. Differences in the trophic structure and functioning of Barents and Norwegian Sea ecosystems as well as factors that might influence the resilience of the marine ecosystems, including climatic fluctuation, variations in prey and predator species abundance, alterations in their regular migrations, and fishing exploitation were also considered. The trophic chain lengths in the deep Norwegian Sea are shorter, and energy transfer occurs mainly through the pelagic fish/invertebrates communities. The shallow Barents Sea is characterized by longer trophic chains, providing more energy flow into their benthic assemblages. The trophic mechanisms observed in the Norwegian Sea food webs dominated by the top-down control, i.e. the past removal of Norwegian Spring spawning followed by zooplankton development and intrusion of blue whiting and mackerel into the area. The wasp-waist response is shown to be the most pronounced effect in the Barents Sea, related to the position of capelin in the ecosystem; large fluctuations in the capelin abundance have been strengthened by intensive fishery. Closer links between ecological and fisheries sciences are needed to elaborate and test various food webs and multispecies models available.

  5. Sea Surface Temperature Seesaw between the Subpolar North Atlantic and the Norwegian Sea during the Late Holocene

    NASA Astrophysics Data System (ADS)

    Miettinen, A.; Divine, D.; Koc, N.; Godtliebsen, F.; Hall, I. R.

    2012-12-01

    August sea surface temperature (aSST) record based on fossil diatom assemblages is generated from a 2800-year-long marine sediment core Rapid 21-COM from the Iceland Basin, in the northern subpolar North Atlantic. The record has a resolution of 2-10 years for interval 800-2004 AD representing the highest-resolution diatom SST reconstruction from the subpolar North Atlantic for this period, and 40 years for interval 800 BC-800 AD. The record is compared with the high-resolution aSST record from core CR948/2011 from the Vøring Plateau, in the Norwegian Sea, to explore the variability of the aSST gradient between these areas during the late Holocene. The aSST records show persistent opposite climate trends toward warming in the subpolar North Atlantic and cooling in the Norwegian Sea during the late Holocene. An apparent tendency to coherent antiphased aSST variations between the sites is also revealed for the shorter time scales implying an aSST seesaw between the northern subpolar North Atlantic and the Norwegian Sea to operate during the late Holocene. At the multicentennial scale of aSST variability of 600-900 years, the records are nearly in antiphase with warmer (colder) periods in the subpolar North Atlantic corresponding to the colder (warmer) periods in the Norwegian Sea. At the shorter time scale of 200-450 years, the records display a phase-locked behaviour with a tendency for the positive aSST anomalies in the Norwegian Sea to lead by ca. 30 years the negative aSST anomalies in the subpolar North Atlantic. This aSST seesaw might have had a strong effect on two major climate anomalies in the northwest Europe during the past Millennium: Medieval Warm Period (MWP) and the Little Ice Age (LIA). During the MWP warming of the sea surface in the Norwegian Sea occurred in parallel with cooling in the northern subpolar North Atlantic, whereas the opposite pattern emerged during the LIA. Coupled changes in aSST between the northern subpolar North Atlantic and the Norwegian Sea indicate common driving forces behind the observed variability. The emerging spatial pattern of changes resembles the one predicted by modelling studies and is associated with rapid changes in the regimes of the Atlantic meridional overturning circulation (AMOC). The observed aSST seesaw between the subpolar North Atlantic and the Norwegian Sea could be a surface expression of the variability of the eastern and western branches of the AMOC with a possible amplification through atmospheric feedback.; Location of the core sites Rapid 21-COM and CR 948/2011, and the relative aSST patterns during the LIA and the MWP. Red arrows indicate surface currents with higher heat flux, orange (blue) shading indicates warm (cool) surface waters.

  6. Scalar winds from SSM/I in the Norwegian and Greenland seas during Norcsex

    NASA Technical Reports Server (NTRS)

    Gloersen, Per; Hubanks, Paul

    1989-01-01

    Data acquired with the Defense Meteorological Satellite Program (DMSP) special sensor microwave imager (SSM/I) during the Norwegian Coastal Sea Experiment (Norcsex) in March 1988 have been utilized to estimate scalar winds in the Norwegian and Greenland Seas. The algorithm for calculating these winds was first developed for the Nimbus-7 scanning multichannel microwave radiometer (SMMR) in order to investigate scalar winds during the Polar Lows Experiment in February 1984. The coefficients in this algorithm have been tuned to accommodate differences in the SSM/I and SMMR instruments.

  7. Ventilation of the deep Greenland and Norwegian seas: evidence from krypton-85, tritium, carbon-14 and argon-39

    NASA Astrophysics Data System (ADS)

    Smethie, W. M.; Ostlund, H. G.; Loosli, H. H.

    1986-05-01

    On leg 5 of the TTO expedition, the distributions of 85Kr, tritium, 14C, 39Ar, temperature, salinity, oxygen, carbon dioxide and nutrients were measured in the Greenland and Norwegian seas. These observations support previous observations that Greenland Sea Deep Water is formed by a deep convective process within the Greenland gyre. They also support AAGAARDet al.'s (1985, Journal of Geophysical Research, 90, 4833-4846) new hypothesis that Norwegian Sea Deep Water forms from a mixture of Greenland Sea Deep Water and Eurasian Basin Deep Water. Volume transports estimated from the distributions of 85Kr, tritium, 14C and 39Ar range from 0.53 to 0.74 Sv for exchange between the surface and deep Greenland Sea and from 0.9 to 1.47 Sv for exchange between the deep Greenland and deep Norwegian seas. The residence time of water in the deep Greenland Sea with respect to exchange with surface water ranges from 24 to 34 years compared to 26-31 years reported by PETERSON and ROOTH (1976, Deep-Sea Research, 23, 273-283) and 35-42 years reported by BULLISTER and WEISSS (1983, Science, 221, 265-268). The residence time of water in the deep Norwegian Sea with respect to exchange with the deep Greenland Sea ranges from 19 to 30 years compared to 97-107 years reported by PETERSON and ROOTH (1976) and 10-28 years reported by BULLISTER and WEISS (1983). The oxygen consumption rate was estimated to be at most 1.04 μM kg -1 y -1 for the deep Greenland Sea and to be between 0.47 and 0.79 μM kg -1 y -1 for the deep Norwegian Sea.

  8. Bioaccumulation of 137Cs in pelagic food webs in the Norwegian and Barents Seas.

    PubMed

    Heldal, Hilde Elise; Føyn, Lars; Varskog, Per

    2003-01-01

    Knowledge and documentation of the levels of radioactive contamination in fish stocks important to Norwegian fisheries is of major importance to Norwegian consumers and fish export industry. In the present study, the bioaccumulation of caesium-137 ((137)Cs) has been investigated in marine food webs in the Barents and Norwegian Seas. The contents of (137)Cs in the different organisms were generally low (<1 Bq kg(-1) wet weight), but a marked bioaccumulation was apparent: The concentration of (137)Cs was about 10-fold higher in the harbour porpoise Phocoena phocoena, representing the upper level of the food web, than in the amphipod Themisto sp., representing the lower level of the food web. The Concentration Factors (CF=Bq kg(-1) wet weight/Bq l(-1) seawater) increased from 10+/-3 for a mixed sample of krill and amphipods to 165+/-5 for harbour porpoises. PMID:12527234

  9. A study of oceanic surface heat fluxes in the Greenland, Norwegian, and Barents Seas

    NASA Technical Reports Server (NTRS)

    Hakkinen, Sirpa; Cavalieri, Donald J.

    1989-01-01

    This study examines oceanic surface heat fluxes in the Norwegian, Greenland, and Barents seas using the gridded Navy Fleet Numerical Oceanography Central surface analysis and the First GARP Global Experiment (FGGE) IIc cloudiness data bases. Monthly and annual means of net and turbulent heat fluxes are computed for the FGGE year 1979. The FGGE IIb data base consisting of individual observations provides particularly good data coverage in this region for a comparison with the gridded Navy winds and air temperatures. The standard errors of estimate between the Navy and FGGE IIb winds and air temperatures are 3.6 m/s and 2.5 C, respectively. The computations for the latent and sensible heat fluxes are based on bulk formulas with the same constant heat exchange coefficient of 0.0015. The results show extremely strong wintertime heat fluxes in the northern Greenland Sea and especially in the Barents Sea in contrast to previous studies.

  10. Watermass evolution and ice-drift patterns in the subarctic Norwegian Sea during the Holocene

    NASA Astrophysics Data System (ADS)

    Bauch, H. A.; Kandiano, E. S.

    2012-04-01

    Holocene climate records from the polar North show a strong tie to changes in insolation in general and, on the regional scale, to the particular post-glacial environmental development. Because the eastern Nordic seas act as through road for the oceanic heat into the Arctic Ocean we have investigated two crucial oceanographic components in the southern Norwegian Sea, the Arctic Front (AF) and the Norwegian Atlantic Current (NAC). Using deep-sea sediment records we analyzed different foraminiferal species for O-isotopes and interpreted the planktic foraminiferal assemblage variations in combination with records of ice-rafted detritus (IRD). It is shown that after adjacent ice shelves and glaciers had retreated inland and away from the coastlines highest surface temperatures occurred between 10.5 and 8.5 ka. An intermittent cold phase around 8 ka is associated with both IRD and increased abundance of polar species N. pachyderma (s). Afterwards, high surface temperature were regained but started to decrease at the AF after 6 ka, concomitant with a persistent occurrence of IRD. This cooling trend continued into the latest Holocene when highest IRD input is noted. Within the NAC, relatively stable and warm conditions are still found between 2.5 and 1 ka, in both planktic and benthic O-isotopes. Although variability among certain foraminiferal species would indicate some surface changes, the abundance of N. pachyderma (s) increased from 30 % to 70 % during the last 1ka (Little Ice Age). This increase is associated with highly variable O-isotope values throughout the entire water column. We interpet the records of the past 10.5 ka, and in particular the times when rather cold surface conditions prevailed, to be the result of changes in overall atmospheric circulation. These caused an intensification of the gyre system in the Greenland and Iceland seas thereby rerouting polar water masses, and probably winter sea ice, far into the eastern Nordic seas.

  11. The Norwegian Danish Basin: A key to understanding the Cenozoic in the eastern North Sea

    NASA Astrophysics Data System (ADS)

    Rasmussen, Thomas L.; Clausen, Ole R.; Andresen, Katrine J.; Goledowski, Bartosz

    2015-04-01

    The Danish part of Norwegian-Danish Basin, which constitutes the eastern part of the North Sea Basin, has been the key area for sequence stratigraphic subdivision and analysis of the Cenozoic succession since the mid 1990's. Widespread 3D seismic data, in the central parts of the North Sea Basin, as well as more scattered 3D seismic data in the Danish part of the Norwegian-Danish Basin, have given a more detailed understanding of the sequences and indicate that climate is tenable for the origin of Cenozoic sequence boundaries. The previous sequence stratigraphic interpretations have been an integrated part of an ongoing debate concerning vertical movements of the Fennoscandian shield versus the impact of climate and erosion. A newly accessed coherent regional 2D and reprocessed 3D seismic data set, in the Norwegian part of the Norwegian-Danish Basin, constitute the database for a new sequence stratigraphic analysis of the entire area. The objective of the new study is to test previous subdivisions and introduce a coherent 3D sequence stratigraphic analysis and depositional model for the entire Norwegian-Danish Basin. This analysis is necessary to get out of the stalemate with the uplift discussion. The study shows that the original subdivision by Michelsen et al. (1995, 1998) stands. However, revision of few a sequence boundaries may have to be adjusted due to new biostratigraphic information published. Furthermore, high-angle clinoforms and geomorphological transport complexes observed in the Danish North Sea Basin can be traced into the Norwegian sector. This together with the recognition of several other high-angle clinoform complexes, and their associated seismic facies distribution maps and thickness-maps, enhances the level of detail and constrains the previous published paleogeographic reconstructions of the Cenozoic. The geometry of the Cenozoic infill, in the Norwegian part of the Norwegian-Danish Basin, is here interpreted to be controlled by relative sea-level changes and sourced from the Scandinavian hinterland. 3D-Wheeler diagrams have been used for recognizing spatial elements with periods of deposition and non-deposition. Overall, this study thus contributes significantly to a better understanding of the Cenozoic evolution, the position of potential reservoirs and the debate of climate versus tectonics. References: Michelsen, O., M. Danielsen, C. Heilmann-Clausen, H. Jordt, G. V. Laursen and E. Thomsen, Eds. (1995). Occurrence of major sequence stratigraphic boundaries in relation to basin development in Cenozoic deposits of the southeastern North Sea. Sequence Stratigraphy: Advances and Applications for Exploration and Producing in North West Europe vol 5. Amsterdam, Elsevier. Michelsen, O., E. Thomsen, M. Danielsen, C. Heilmann-Clausen, H. Jordt and G. V. Laursen (1998). Cenozoic sequence stratigraphy in the eastern North Sea. Mesozoic-Cenozoic Sequence Stratigraphy of Western European Basins. P. C. de Graciansky, T. Jacquin and P. R. Vail, Society of Economic Palaeontolgists and Mineralogists Special Publication 60. 60: 91-118.

  12. An overview of the ecosystems of the Barents and Norwegian Seas and their response to climate variability

    NASA Astrophysics Data System (ADS)

    Loeng, Harald; Drinkwater, Ken

    2007-11-01

    The principal features of the marine ecosystems in the Barents and Norwegian Seas and some of their responses to climate variations are described. The physical oceanography is dominated by the influx of warm, high-salinity Atlantic Waters from the south and cold, low-salinity waters from the Arctic. Seasonal ice forms in the Barents Sea with maximum coverage typically in March-April. The total mean annual primary production rates are similar in the Barents and Norwegian Seas (80-90 g C m -2), although in the Barents, the production is higher in the Atlantic than in the ice covered Arctic Waters. The zooplankton is dominated by Calanus species, C. finmarchicus in the Atlantic Waters of the Norwegian and Barents Seas, and C. glacialis in the Arctic Waters of the Barents Sea. The fish species in the Norwegian Sea are mostly pelagics such as herring ( Clupea harengus) and blue whiting ( Micromesistius poutassou), while in the Barents Sea there are both pelagics (capelin ( Mallotus villosus Mülle r), herring, and polar cod ( Boreogadus saida Lepechin)) and demersals (cod ( Gadus morhua L.) and haddock ( Melanogrammus aeglefinus)). The latter two species spawn in the Norwegian Sea along the slope edge (haddock) or along the coast (cod) and drift into the Barents Sea. Marine mammals and seabirds, although comprising only a relatively small percentage of the biomass and production in the region, play an important role as consumers of zooplankton and small fish. While top-down control by predators certainly is significant within the two regions, there is also ample evidence of bottom-up control. Climate variability influences the distribution of several fish species, such as cod, herring and blue whiting, with northward shifts during extended warm periods and southward movements during cool periods. Climate-driven increases in primary and secondary production also lead to increased fish production through higher abundance and improved growth rates.

  13. Cenozoic Contourite Drift Development in the Norwegian - Greenland Sea Area: Paleoceanographic Implications

    NASA Astrophysics Data System (ADS)

    Laberg, J. S.; Rebesco, M.; Lucchi, R. G.; Stoker, M. S.

    2014-12-01

    For the evolution of the Cenozoic high northern latitude paleo-climate, the development of the North Atlantic - Arctic Ocean interactions including its southern (Faeroe - Shetland channel) and northern (Fram Strait) gateways were vital. In this paper we review the timing of inflow of paleo-Atlantic water into the Norwegian - Greenland Sea and the Arctic Ocean using the development of ocean current controlled contourite drift deposition as a proxy. In the early Miocene, drift growth accelerated in the Rockall Trough and in the Faroe-Shetland Channel interpreted to be related to the opening of the Faeroe - Shetland channel and establish a deep-water passage across the Greenland - Shetland Ridge. To the north, offshore Norway, growth of the Lofoten Drift has been estimated from mid-Miocene although age control is sparse in this area. No drift development has been reported from the SW Barents Sea continental slope while offshore the NW part of the Barents Sea slope, drift growth seems to have come in later, at ~1.3 Ma. North of the Fram Strait gateway, drift growth has been inferred from at least mid-Miocene (~11 Ma). Studies from the central Arctic Ocean shows ventilated surface water conditions from ~17.5 Ma ascribed to the opening of the Fram Strait which was a narrow oceanic corridor during early Miocene (20 - 15 Ma) and where the onset of sea floor spreading and the establishment of a deep-water corridor has been suggested to start from late Miocene (~10 Ma). Other, more recent studies have, however, reported evidence for the development of an initial deep-water gateway through the Fram Strait from around 17 Ma. To summarize: - A circulation system similar to the present was probably established in the southern Norwegian - Greenland Sea before the Fram Strait became a deep-water gateway and before the establishments of the major ice sheets in this area (the first occurred in SE Greenland from ~7 Ma). - Uncertainties still relates to the timing of the development of ocean circulation in the northern Norwegian - Greenland Sea including the Fram Strait gateway where drift onset has been estimated to at least 11 Ma. - The onset of drift growth at 1.3 Ma slightly south of the Fram Strait occurred after the onset of deep-water circulation through the Fram Strait and it is inferred to be related to the glacial expansion recorded in the area.

  14. Neogene Contourite Drift Development in the Norwegian - Greenland Sea Area; Paleoceanographic Implications

    NASA Astrophysics Data System (ADS)

    Sverre Laberg, Jan; Rebesco, Michele; Lucchi, Renata G.; Stoker, Martyn S.

    2015-04-01

    For the evolution of the Cenozoic high northern latitude paleo-climate, the development of the North Atlantic - Arctic Ocean interactions including its southern (Faeroe - Shetland channel) and northern (Fram Strait) gateways were vital. In this paper we review the timing of inflow of paleo-Atlantic water into the Norwegian - Greenland Sea and the Arctic Ocean using the development of ocean current controlled contourite drift deposition as a proxy. In the early Miocene, drift growth accelerated in the Rockall Trough and in the Faroe-Shetland Channel interpreted to be related to the opening of the Faeroe - Shetland channel and establish a deep-water passage across the Greenland - Shetland Ridge. To the north, offshore Norway, growth of the Lofoten Drift has been estimated from mid-Miocene although age control is sparse in this area. No drift development has been reported from the SW Barents Sea continental slope while offshore the NW part of the Barents Sea slope, drift growth seems to have come in later, at ~1.3 Ma. North of the Fram Strait gateway, drift growth has been inferred from at least mid-Miocene (~11 Ma). Studies from the central Arctic Ocean shows ventilated surface water conditions from ~17.5 Ma ascribed to the opening of the Fram Strait which was a narrow oceanic corridor during early Miocene (20 - 15 Ma) and where the onset of sea floor spreading and the establishment of a deep-water corridor has been suggested to start from late Miocene (~10 Ma). Other, more recent studies have, however, reported evidence for the development of an initial deep-water gateway through the Fram Strait from around 17 Ma. To summarize: - A circulation system similar to the present was probably established in the southern Norwegian - Greenland Sea before the Fram Strait became a deep-water gateway and before the establishments of the major ice sheets in this area (the first occurred in SE Greenland from ~7 Ma). - Uncertainties still relates to the timing of the development of ocean circulation in the northern Norwegian - Greenland Sea including the Fram Strait gateway where drift onset has been estimated to at least 11 Ma. - The onset of drift growth at 1.3 Ma slightly south of the Fram Strait occurred after the onset of deep-water circulation through the Fram Strait and it is inferred to be related to the glacial expansion recorded in the area.

  15. Simulations of the mesoscale circulation of the Greenland-Iceland-Norwegian Seas

    NASA Technical Reports Server (NTRS)

    Heburn, George W.; Johnson, Clifford D.

    1995-01-01

    The Greenland, Iceland, and Norwegian Seas provide the only link between the North Atlantic and the Arctic Oceans. This is a very dynamic region, rich in mesoscale variability. A two-layer, hydrodynamic version of the Navy layered ocean model is used to simulate the mesoscale frontal features and associated current systems. The model is wind-driven using monthly mean wind stresses and inflow/outflow mass flux from the Arctic and North Atlantic Oceans. The current transports from the model results compare favorably with transport measurements from a number of observational experiments.

  16. Distribution and diversity patterns of asellote isopods (Crustacea) in the deep Norwegian and Greenland Seas

    NASA Astrophysics Data System (ADS)

    Svavarsson, Jrundur; Brattegard, Torleiv; Strmberg, Jarl-Ove

    Distribution and diversity patterns of asellote isopods (Crustacea) of the deep Norwegian and Greenland Seas are described. The asellotes show the same pattern of rapid faunal change across the upper continental slope as commonly described elsewhere. Here the rate of species replacement is maximum at depths of 800-1000m, but decreases towards greater depths. The distribution of the asellotes shows some correlations to the distribution of sediment types. Species diversity is maximum at 800m and decreases with depth. The species diversity pattern is related here to heterogeneity of the sediments and different species immigration rates into shallow and deep Arctic waters.

  17. Overseas trip report, CV 990 underflight mission. [Norwegian Sea, Greenland ice sheet, and Alaska

    NASA Technical Reports Server (NTRS)

    Gloersen, P.; Crawford, J.; Hardis, L.

    1980-01-01

    The scanning microwave radiometer-7 simulator, the ocean temperature scanner, and an imaging scatterometer/altimeter operating at 14 GHz were carried onboard the NASA CV-990 over open oceans, sea ice, and continental ice sheets to gather surface truth information. Data flights were conducted over the Norwegian Sea to map the ocean polar front south and west of Bear Island and to transect several Nimbus-7 footprints in a rectangular pattern parallel to the northern shoreline of Norway. Additional flights were conducted to obtain correlative data on the cryosphere parameters and characteristics of the Greenland ice sheet, and study the frozen lakes near Barrow. The weather conditions and flight path way points for each of the nineteen flights are presented in tables and maps.

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

    NASA Astrophysics Data System (ADS)

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

    2014-09-01

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

  19. Changes in significant and maximum wave heights in the Norwegian Sea

    NASA Astrophysics Data System (ADS)

    Feng, Xiangbo; Tsimplis, M. N.; Yelland, M. J.; Quartly, G. D.

    2014-02-01

    This paper analyses 10 years of in-situ measurements of significant wave height (Hs) and maximum wave height (Hmax) from the ocean weather ship Polarfront in the Norwegian Sea. The 30-minute Ship-Borne Wave Recorder measurements of Hmax and Hs are shown to be consistent with theoretical wave distributions. The linear regression between Hmax and Hs has a slope of 1.53. Neither Hs nor Hmax show a significant trend in the period 2000-2009. These data are combined with earlier observations. The long-term trend over the period 1980-2009 in annual Hs is 2.72 ± 0.88 cm/year. Mean Hs and Hmax are both correlated with the North Atlantic Oscillation (NAO) index during winter. The correlation with the NAO index is highest for the more frequently encountered (75th percentile) wave heights. The wave field variability associated with the NAO index is reconstructed using a 500-year NAO index record. Hs and Hmax are found to vary by up to 1.42 m and 3.10 m respectively over the 500-year period. Trends in all 30-year segments of the reconstructed wave field are lower than the trend in the observations during 1980-2009. The NAO index does not change significantly in 21st century projections from CMIP5 climate models under scenario RCP85, and thus no NAO-related changes are expected in the mean and extreme wave fields of the Norwegian Sea.

  20. CO2 Storage Atlas Norwegian Sea - a case study from the Froan Basin

    NASA Astrophysics Data System (ADS)

    Sande Rød, Rita; Pham, Van T. H.

    2014-05-01

    The CO2 storage atlas of the Norwegian Sea has been prepared by the Norwegian Petroleum Directorate at the request of the Ministry of Petroleum and Energy. The main objectives have been to identify the safe and effective areas for long-term storage of CO2 and to avoid possible negative interference with ongoing and future petroleum activity. We have built on the knowledge we have from the petroleum industry and from the two ongoing CO2 storage projects, Sleipner and Snøhvit, on the Norwegian Continental Shelf. Five aquifers and six prospects have been evaluated in terms of storage capacity and safe storage of CO2. One identified storage potential is the Froan Basin Garn and Ile Formations. The Froan Basin is a NE striking Jurassic syncline on the southwestern part of the Trøndelag Platform. The aquifers in the southeastern part of the Norwegian Sea typically have a consistent dip of 1-2 degrees from the Norwegian coast to the basinal areas. In the case of permeable beds occurring along the dip slope there is a risk that CO2 injected down dip can migrate up to where the aquifer is truncated by the Quaternary glacial sediments. A simulation study was performed in order to identify possible trapping mechanisms and to understand the timing and extent of long distance CO2 migration. The storage mechanisms considered were both structural and stratigraphic trapping. A simulation sector model of the Garn/Not/Ile Formations was build covering about 10% of the total expected communicating aquifer volume. The CO2 injection well was located down dip, but alternative locations and injection zones have been simulated, with different injection rates. The injection period is 50 years, and the migration of the CO2 plume was simulated and monitored for 10.000 years. CO2 will continue to migrate upwards as long as it is in free, movable state. Migration stops when CO2 is permanently bounded or trapped, by going into solution with the formation water or by being residually trapped, or becoming structurally trapped (mineralogical trapping not considered). Based on simulation results about 400 mill tons CO2 can be stored in the Garn and Ile aquifer (8 mill tons/year over 50 years). This will require 4 injection and give acceptable pressure increase (<20bar). Within 10000 years most of the gas will have gone into solution with the formation water or being residually trapped.

  1. Feeding Ecology of Northeast Atlantic Mackerel, Norwegian Spring-Spawning Herring and Blue Whiting in the Norwegian Sea

    PubMed Central

    Bachiller, Eneko; Skaret, Georg; Nøttestad, Leif; Slotte, Aril

    2016-01-01

    The Norwegian spring-spawning (NSS) herring (Clupea harengus), blue whiting (Micromesistius poutassou) and Northeast Atlantic (NEA) mackerel (Scomber scombrus) are extremely abundant pelagic planktivores that feed in the Norwegian Sea (NS) during spring and summer. This study investigated the feeding ecology and diet composition of these commercially important fish stocks on the basis of biological data, including an extensive set of stomach samples in combination with hydrographical data, zooplankton samples and acoustic abundance data from 12 stock monitoring surveys carried out in 2005–2010. Mackerel were absent during the spring, but had generally high feeding overlap with herring in the summer, with a diet mainly based on calanoid copepods, especially Calanus finmarchicus, as well as a similar diet width. Stomach fullness in herring diminished from spring to summer and feeding incidence was lower than that of mackerel in summer. However, stomach fullness did not differ between the two species, indicating that herring maintain an equally efficient pattern of feeding as mackerel in summer, but on a diet that is less dominated by copepods and is more reliant on larger prey. Blue whiting tended to have a low dietary overlap with mackerel and herring, with larger prey such as euphausiids and amphipods dominating, and stomach fullness and feeding incidence increasing with length. For all the species, feeding incidence increased with decreasing temperature, and for mackerel so did stomach fullness, indicating that feeding activity is highest in areas associated with colder water masses. Significant annual effects on diet composition and feeding-related variables suggested that the three species are able to adapt to different food and environmental conditions. These annual effects are likely to have an important impact on the predation pressure on different plankton groups and the carrying capacity of individual systems, and emphasise the importance of regular monitoring of pelagic fish diets. PMID:26895485

  2. Feeding Ecology of Northeast Atlantic Mackerel, Norwegian Spring-Spawning Herring and Blue Whiting in the Norwegian Sea.

    PubMed

    Bachiller, Eneko; Skaret, Georg; Nøttestad, Leif; Slotte, Aril

    2016-01-01

    The Norwegian spring-spawning (NSS) herring (Clupea harengus), blue whiting (Micromesistius poutassou) and Northeast Atlantic (NEA) mackerel (Scomber scombrus) are extremely abundant pelagic planktivores that feed in the Norwegian Sea (NS) during spring and summer. This study investigated the feeding ecology and diet composition of these commercially important fish stocks on the basis of biological data, including an extensive set of stomach samples in combination with hydrographical data, zooplankton samples and acoustic abundance data from 12 stock monitoring surveys carried out in 2005-2010. Mackerel were absent during the spring, but had generally high feeding overlap with herring in the summer, with a diet mainly based on calanoid copepods, especially Calanus finmarchicus, as well as a similar diet width. Stomach fullness in herring diminished from spring to summer and feeding incidence was lower than that of mackerel in summer. However, stomach fullness did not differ between the two species, indicating that herring maintain an equally efficient pattern of feeding as mackerel in summer, but on a diet that is less dominated by copepods and is more reliant on larger prey. Blue whiting tended to have a low dietary overlap with mackerel and herring, with larger prey such as euphausiids and amphipods dominating, and stomach fullness and feeding incidence increasing with length. For all the species, feeding incidence increased with decreasing temperature, and for mackerel so did stomach fullness, indicating that feeding activity is highest in areas associated with colder water masses. Significant annual effects on diet composition and feeding-related variables suggested that the three species are able to adapt to different food and environmental conditions. These annual effects are likely to have an important impact on the predation pressure on different plankton groups and the carrying capacity of individual systems, and emphasise the importance of regular monitoring of pelagic fish diets. PMID:26895485

  3. Contributions to sea level variability along the Norwegian coast for 1960-2010

    NASA Astrophysics Data System (ADS)

    Richter, K.; Nilsen, J. E. Ø.; Drange, H.

    2012-05-01

    Global sea level has been rising by about 20 cm during the last century and is expected to continue to rise in the 21st century. The rise and variability is not spatially uniform. To be able to project local changes in relative sea level (RSL), it is important to identify the processes that govern regional RSL variability. In this study, we assess the importance of different contributions to RSL variability along the coast of Norway in the period 1960-2010. By using hydrographic station data at the coast, sea level pressure, and observed vertical land uplift, we compute RSL changes due to thermal expansion, haline contraction, the inverted barometer effect, and land uplift caused by glacial isostatic adjustment. The combination of these contributions is compared to RSL variability observed with tide gauges. For all but the two southernmost stations, the reconstructed RSL explains 70-85% of the observed variability of the monthly sampled time series. The inverted barometer effect is responsible for more than half of the explained variability, while thermosteric height represents the largest contribution to the linear trend. Due to land uplift, the local RSL rise is weaker and partly negative along the Norwegian coast. The residual (observed minus reconstructed) shows a positive trend ranging from 1.3 mm yr-1 to 2.3 mm yr-1. It is speculated that the reason for this is an increase of mass in the ocean due to melting of land-based ice and, to a lesser degree, the combined thermohaline expansion in the deep Nordic seas.

  4. High diversity of microplankton surrounds deep-water coral reef in the Norwegian Sea.

    PubMed

    Jensen, Sigmund; Bourne, David G; Hovland, Martin; Murrell, J Colin

    2012-10-01

    Coral reefs that exist in the depths of the oceans are surrounded by Eukarya, Archaea and bacterial communities that may play an important role in the nutrition and health of the reef. The first interdomain community structure of planktonic organisms in seawater from a deep-water coral reef is described. Community profiling and analysis of ribosomal RNA gene sequences from a coral reef system at 350 m depth in the Norwegian Sea revealed a rich diversity of Eukarya and Bacteria and a moderate diversity of Archaea. Most sequences affiliated with marine microplankton from deep-sea to cold-surface regions, with many sequences being similar to those described in studies of mesopelagic and oxygen minimum zones. Dominant phylotypes belonged to the Alveolata (group I, II, dinoflagellates), Stramenopiles (silicoflagellates), Alphaproteobacteria (Pelagibacter ubique), Gammaproteobacteria (ARCTIC96BD-19), Bacteroidetes (Flavobacteria) and mesophilic Crenarchaeota (Nitrosopumilus maritimus). Several rare and novel members of the community fell into distinct phylogenetic groups. The inferred function of dominant community members suggested autotrophs that utilise light, ammonium or sulphide, and lifestyles based on host associations. The high diversity reflected a microplankton community structure, which is significantly different from that of microplankton collected at the same depth at a pelagic station away from reefs. PMID:22571287

  5. Airborne Measurements of Emissions from Oil and Gas Exploration and Production Activities in the Norwegian Sea

    NASA Astrophysics Data System (ADS)

    Kim, J.; Roiger, A.; Raut, J.; Rose, M.; Weinzierl, B.; Reiter, A.; Thomas, J. L.; Marelle, L.; Law, K.; Schlager, H.

    2013-12-01

    A rapid decline of Arctic sea ice is expected to promote hydrocarbon extraction in the Arctic, which in turn will increase emissions of atmospheric pollutants. To investigate impacts of different pollution sources on the Arctic atmosphere, an aircraft campaign based in northern Norway was conducted in July 2012, as a part of the EU ACCESS (Arctic Climate Change Economy and Society) project. One of the flights focused on measuring emissions from various oil/gas exploration and production facilities ~110 km south of the Arctic Circle in the Norwegian Sea. Fresh and aged (from 5 minutes to 2.5 hours old) exhaust plumes from oil/gas production platforms, drilling rigs and tankers were probed with extensive aerosol and trace gas instrumentations. It was found that different types of facilities emit plumes with distinct chemical compositions. For example, tanker plumes were characterized by high SO2 concentration and high fraction of non-volatile particles while plumes from oil/gas production platforms showed significant increase in the nucleation mode particle concentration. Drilling rigs were found to be high black carbon emitters. In addition to the fresh plumes, relatively aged plumes (1.5 - 2.5 hours old) from a facility under development were measured. Even in these aged plumes, total particle concentrations were more than 6 times higher than the background concentration. Therefore, emissions from oil and gas activities are expected to have a significant impact on local air quality and atmospheric composition. With the aid of FLEXPART-WRF (a Lagrangian dispersion model) simulations, the results of this study will be used to validate and improve current emission inventories. In the future, these improved emission inventories can be used in regional and global chemical transport models to more accurately predict future Arctic air pollution.

  6. Salt distribution in the Norwegian-Danish Basin, Central North Sea

    NASA Astrophysics Data System (ADS)

    Sassier, Caroline; Jarsve, Erlend; Heeremans, Michel; Mansour Abdelmalak, Mohamed; Faleide, Jan Inge; Helge Gabrielsen, Roy

    2014-05-01

    Salt tectonics have extensively been studied in most parts of the Central North Sea. However, few studies have been done in the Norwegian side of the Norwegian-Danish Basin. In this contribution, we report a new regional analysis of the salt patterns across the offshore Norwegian-Danish Basin. We have mapped the regional distribution of salt structures in the Norwegian-Danish Basin using both old and recent 2D seismic reflection profiles tied to wells. The salt-thickness map shows three distinct salt structures patterns: (1) NW-SE trending salt walls in the northern part of the basin; the spacing between the walls vary between 7 to 12 km; (2) a dense and irregular distribution of salt diapirs in the southern part of the studied area; (3) an irregular pattern of sparse but big salt diapirs in the eastern part of the basin. This domain is characterized by numerous turtle structures associated with salt diapirs. Reflection seismic cross-sections show that most salt structures only pierce the Triassic sedimentary strata whereas only few salt structures reach the seabed. Rotated fault blocks indicate a gliding vergence towards the South in the eastern part of the basin and towards the SE in the western side of the Norwegian-Danish Basin. No mature or compressive salt structures, except some squeezed salt diapirs, are observed in the topographic lows of the basin. The initiation of salt tectonics started during the early Middle Triassic in the entire basin; salt tectonics reactivations were recorded during the Middle Jurassic, Paleogene, and prior to the Quaternary but are not homogeneous across the basin. Salt movements inferred from our study are in good agreement with previous studies. The trend of salt walls (domain 1) indicates a NE-SW extension which is not compatible with N-S trending pre-salt faults. Instead, the strong Triassic subsidence towards the SW has most likely controlled the formation of the salt walls. The salt was initially thicker in domain 2 that also corresponds to the main depocenter of the first Triassic sequence. We suggest that both the salt thickness and the sedimentary differential loading, combined with the subsidence of the basin, have influenced the change of the salt pattern in domain 2. In domain 3, the reactivation of pre-salt faults might have triggered some of the salt structures. This area also received a large amount of sediments from the Skagerrak area during the Triassic subsidence, which may have influenced the distribution and evolution of salt diapirs and turtle structures. The combination of the different triggering processes and the different basin geometry of domain 3, which is bounded by highs to the South and North, in comparison to domain 2 which is open towards the Central Graben, are probably the key parameters that have controlled the salt pattern in this area. Finally, salt tectonics reactivations were likely controlled by the distribution of younger sediments and the successive tectonic regimes.

  7. Influence of lithofacies and diagensis on Norwegian North Sea chalk reservoirs

    SciTech Connect

    Brasher, J.E.; Vagle, K.R.

    1996-05-01

    The depositional mechanism of chalk is a key influence in the chalk`s ultimate reservoir quality. Classically, the depositional mechanism is interpreted from core descriptions. Where core data are lacking, dipmeter and borehole imagery logs have proven useful in making lithofacies assessments. Criteria for recognition of three chalk categories are established. Category III chalks correspond to those chalks that have been deposited by gravity flows or slumping and tend to have the best reservoir parameters. Category I chalks are most often affiliated with pelagic deposition and tend to have the poorest reservoir parameters. Category II chalks are intermediate between I and III. Anomalously high primary porosities have been maintained in Norwegian North Sea chalks where the effects of mechanical and chemical compaction have been limited. The diagenetic pathway of a chalk reflects changes brought about by mechanical and chemical compaction. Five factors most heavily influence the diagenetic pathway: (1) burial depth, (2) chalk type, (3) overpressuring, (4) presence of hydrocarbons, and (5) original grain size. Assessments of the sedimentological model, diagenetic pathway, and resultant reservoir quality are provided in case studies of Edda, Tor, and Eldfisk fields. Because the distribution of chalk is largely independent of existing structures, most fields have a component of stratigraphic/diagenetic trapping. Each case study shows unique examples of how petrophysical and reservoir engineering data can be incorporated in assessments of chalk type and the diagenetic pathway and how they may affect reservoir parameters and productivity.

  8. Conjugate volcanic rifted margins, spreading and micro-continent: Lessons from the Norwegian-Greenland Sea

    NASA Astrophysics Data System (ADS)

    Gernigon, L.; Blischke, A.; Nasuti, A.; Sand, M.

    2014-12-01

    We have acquired and processed new aeromagnetic data that covers the entire Norway Basin oceanic spreading system located between the Møre volcanic rifted margin and its (intermediate) conjugate system, the Jan Mayen microcontinent (JMMC). The new compilation allows us to revisit its entire structure and spreading evolution from the Early Eocene breakup to the Late Oligocene abortion of the Aegir Ridge. We here discuss the dynamics of conjugate volcanic (rifted) margin formation and reconstruct the subsequent spreading evolution of the Norway Basin until its abortion. We have estimated a new set of Euler poles of rotation for the Norway Basin derived from more than 88,000 km of new magnetic profiles. The new compilation confirms that a fan-shaped spreading evolution of the Norway Basin was particularly active before the cessation of seafloor spreading and abortion of the Aegir Ridge. The Norway Basin shows a more complex system of micro-plates and asymmetric segments locally affected by episodic ridge jumps. The new observations have implications for the syn- and post-breakup stratigraphic and rifted-margin tectonic development of the JMMC and its conjugate margins. In particular, an important Mid-Eocene geodynamic event at around magnetic chron C21r is recognized in the Norway Basin. This event coincides with the onset of diking and rifting between the proto-JMMC and the East Greenland margin, leading to a second phase of breakup in the Norwegian-Greenland Sea ~26 My later in the Oligocene. Restored in its pre-breakup configuration, the new surveys also allow us to discuss further the tectonic and crustal evolution of the conjugate volcanic rifted margins and associated transform and oblique segments. The applicability of magma-poor concepts, off Norway, for example, remains questionable for us. The significant amount of breakup magmatism, the huge amount of pre-breakup sag sedimentation and the presence of thinned and preserved continental crust without the systematic occurrence of underlying and/or exhumed serpentinised terranes. The mid-Norwegian volcanic rifted margins appear quite different from the Iberian type, magma-poor margin, even if the processes leading to the early (and aborted) thinning events seems to be similar to some extent.

  9. Water mass exchanges between the Norwegian and Iceland seas over the Jan Mayen Ridge using in-situ current measurements

    NASA Astrophysics Data System (ADS)

    Mork, Kjell Arne; Drinkwater, Kenneth F.; Jónsson, Steingrímur; Valdimarsson, Héðinn; Ostrowski, Marek

    2014-11-01

    The Jan Mayen Ridge, with bottom depths of 1000 m and less, runs southwards from Jan Mayen and separates the warmer and saltier Atlantic Water in the Norwegian Sea from the colder and fresher Arctic water in the Iceland Sea. During the International Polar Year (IPY, 2007-2008), three current meter moorings were deployed with the purpose to investigate water mass exchanges between the Norwegian and Iceland seas over the Ridge and their forcing mechanisms. These are the first in-situ current measurements for this region. The results showed relatively weak currents on the Ridge that frequently shifted direction except near-bottom and at the western slope of the Ridge. All current measurements showed low eddy activity and tidal velocities (less than 0.05 ms- 1). Wind-forced near-inertial motion generated from transient atmospheric low pressure systems were observed in the mixed layer being strongest during autumn and winter when ocean velocities reached 0.7 ms- 1. Near surface currents on the Ridge are influenced by local winds on a time scale of 6 days and longer, but during the two-year deployment no pronounced seasonal variation was observed, mainly due to a lack of seasonality in the local winds. In a 2000 m deep channel that cuts the Ridge, there was pronounced seasonal variation in the currents at all depths below 40 m with stronger flow toward the Iceland Sea during winter compared to summer. The variability of the deep current was found to be influenced by the large-scale wind stress curl. There was a weak net flow with averaged velocities of ~ 0.01 ms- 1 over the Ridge that was directed westward in the upper layer, signifying a small net transport of modified Atlantic Water into the Iceland Sea.

  10. On the ecology of Calanus finmarchicus in the Subarctic North Atlantic: A comparison of population dynamics and environmental conditions in areas of the Labrador Sea-Labrador/Newfoundland Shelf and Norwegian Sea Atlantic and Coastal Waters

    NASA Astrophysics Data System (ADS)

    Head, Erica J. H.; Melle, Webjørn; Pepin, Pierre; Bagøien, Espen; Broms, Cecilie

    2013-07-01

    The Norwegian Sea is generally warmer than the Labrador Sea because it is influenced more by Atlantic Water inflows from the south, whereas the latter receives relatively larger inputs of Arctic Water from the north. Despite its more northerly location, the spring bloom generally starts earlier in the Norwegian Sea. Within each of the two seas, however, there are regional and interannual differences in temperature and the timing of the spring bloom. The responses of Calanus finmarchicus populations to these differences in environmental conditions include differences in physical characteristics (e.g. female size), physiological rates (egg production rates) and seasonal cycles of abundance. Females are generally larger in the Labrador Sea and have higher egg production rates for a given chlorophyll concentration than do those in the Norwegian Sea. Within and among areas in both seas, as temperatures increase and spring blooms tend to occur earlier, C. finmarchicus start to reproduce earlier, the new generation develops faster, and in some areas a second generation ensues. In areas where near surface temperatures are relatively high in summer and/or where phytoplankton growth rates are relatively low in summer or autumn, reproduction and development cease, and C. finmarchicus desert the surface layers for their overwintering depths. This occurs in the Norwegian Sea in summer and in the central Labrador Sea in autumn. By contrast, in areas where near surface temperatures remain cool in summer and where phytoplankton growth persists through the autumn, reproduction and development can continue through summer and autumn, probably until winter vertical mixing prevents phytoplankton growth. This occurs on the southern Newfoundland Shelf. Even in areas where the growth season is prolonged, however, a proportion of the first generation, and probably subsequent generations, descends to overwinter. If the size of the overwintering population is used as an index of net productivity, then for equivalent regions in the Norwegian Sea and Labrador Sea (the areas of each most affected by Atlantic inflow), the differences in ambient temperatures and bloom dynamics apparently have little impact. With global warming, as temperatures in the Norwegian and Labrador Seas increase up to a certain threshold, the timing of life history events for C. finmarchicus will likely be advanced and the number of generations produced per year could increase. The time spent in the near surface layers will probably decrease, however, while the overall effect on population size may not be large. Once the temperature threshold for unfavourable survival of C. finmarchicus has been exceeded, the distribution range for C. finmarchicus will likely contract northwards, with important consequences for dependent species in the affected regions.

  11. The coccolithophores Emiliania huxleyi and Coccolithus pelagicus: Extant populations from the Norwegian-Iceland Seas and Fram Strait

    NASA Astrophysics Data System (ADS)

    Dylmer, C. V.; Giraudeau, J.; Hanquiez, V.; Husum, K.

    2015-04-01

    The distributions of the coccolithophore species Emiliania huxleyi and Coccolithus pelagicus (heterococcolith-bearing phase) in the northern North Atlantic were investigated along two zonal transects crossing Fram Strait and the Norwegian-Iceland Sea, respectively, each conducted during both July 2011 and September-October 2007. Remote-sensing images as well as CTD and ARGO profiles were used to constrain the physico-chemical state of the surface water and surface mixed layer at the time of sampling. Strong seasonal differences in bulk coccolithophore standing stocks characterized the northern and southern transects, where the maximum values of 53×103 cells/l (fall) and 70×103 cells/l (summer), respectively, were essentially explained by E. huxleyi. This pattern confirms previous findings of a summer to fall northwestward shift in peak coccolithophore cell densities within the Nordic Seas. While depicting an overall zonal shift in high cell densities between the summer (Norwegian Sea) and fall (northern Iceland Sea) conditions, the southern transects were additionally characterized by local peak coccolithophore concentrations associated with a geographically and temporally restricted convective process (Lofoten Gyre, summer), as well as an island mass effect (in the vicinity of Jan Mayen Island, fall). Maximum coccolithophore abundances within Fram Strait were found during both seasons close to the western frontal zone (Polar and Arctic Fronts) an area of strong density gradients where physical and chemical properties of the surface mixed layer are prone to enhance phytoplankton biomass and productivity. Here, changes in species dominance from E. huxleyi in summer, to C. pelagicus in fall, were related to the strengthened influence during summer, of surface AW, as well as to high July solar irradiance, within an area usually characterized by C. pelagicus-dominated low density populations.

  12. Integrated interpretation to improve subsalt imaging: a case study from the Nordkapp Basin, Norwegian Barents Sea

    NASA Astrophysics Data System (ADS)

    Olaf Müller, Christian; Brönner, Marco; Götze, Hans-Jürgen

    2015-04-01

    Seismic imaging of subsalt structures is still a difficult task and remaining uncertanties in the salt geometries makes exploration in the vicinity of such complex structures challenging. Gravity and magnetic data have proofed in the past their potential in combination with seismics to better delineate the shape of such salt structures. The current work deals with the improvement of subsalt imaging by combined interpretation of seismic and potential field data examined at a case study from the southern Nordkapp Basin. The Nordkapp Basin is a deep, narrow saliferous basin located in the southwestern Barents Sea. It comprises more than 30 salt diapirs, which are likely to create traps for hydrocarbons at their flanks and overhangs. Consequently exploration of the Nordkapp Basin with seismic methods started already in the 1980s, but until today solely seismics was not sufficient to reveal the nature and geometry for large parts of the basin. Therefore 2D and 3D seismic data were interpreted and used as stratigraphic constraints for the potential field modeling. For this purpose high resolution gravity and full tensor gravity gradient (FTG) data as well as a regional magnetic dataset were available. After processing the potential field data the 3D modeling was conducted by means of the interactive gravity and magnetic modeling software IGMAS+. Furthermore constraints for the rock properties, provided by well logs and susceptibility measurements of adjacent sedimentary well cores, were integrated. The favoured models indicate for both major salt structures a bulky base and a small root. The depth of the base of salt can vary in a range of about ± 300 m. Remaining mother salt is found in the northern part of the survey area and has no connection to the diapiric salt. Due to its higher sensibility to shallower sources the FTG data was used to model the flanks of the salt diapirs. In agreement with adjacent diapirs and encountered sequences a cap rock coverage was detected. Additionally, the gravity data and strong seismic reflections suggest a large impedance contrast and a high density body, consisting of dolomite-dominated carbonates and evaporites at the basin slope in the most southeastern corner of the Nordkapp Basin. In combination with the magnetic data the top of basement is located in 15 to 18 km depth. Furthermore a branch of an intrusion below Norsel High and intrusives in the centre of rift were detected. Our results proof the potential of integrated interpretation of seismic and potential field data. The modeling approach helps to overcome difficulties in seismic imaging of salt structures. Due to the sensibility to sources in different depths, especially FTG data and high resolution magnetic data increase the reliability of subsalt modelling. The resulting model provides additional information to improve seismic velocity models especially in the subsalt area. This study was carried out in the frame of a research project about joint inversion in cooperation with SINTEF, funded by the Norwegian research council, Det norske oljeselskap, Gaz de France and Eon Norge.

  13. The coccolithophores Emiliania huxleyi and Coccolithus pelagicus: extant populations from the Norwegian-Iceland Sea and Fram Strait

    NASA Astrophysics Data System (ADS)

    Dylmer, C. V.; Giraudeau, J.; Hanquiez, V.; Husum, K.

    2013-09-01

    Extant coccolithophores and their relation to the governing oceanographic features in the northern North Atlantic were investigated along two zonal transects of surface water sampling, both conducted during summer 2011 and fall 2007. The northern transects crossed Fram Strait and its two opposing boundary currents (West Spitsbergen Current and East Greenland Current), while the southern transects sampled the Norwegian and Iceland Seas (passing the island Jan Mayen) from the Lofoten Islands to the continental margin off Eastern Greenland. The distribution of the dominant coccolithophore species Emiliania huxleyi and Coccolithus pelagicus is discussed in view of both the surface hydrology at the time of sampling and the structure of the surface mixed layer. Remote-sensing images as well as CTD and ARGO profiles are used to constrain the physico-chemical state of the surface water at the time of sampling. Both transects were characterized by strong seasonal differences in bulk coccolithophore standing stocks with maximum values of 53 × 103 cells L-1 for the northern transect and 72 × 103 cells L-1 for the southern transect in fall and summer, respectively. The highest recorded bulk cell densities are essentially explained by E. huxleyi. This species shows a zonal shift in peak abundance in the Norwegian-Iceland Seas from a summer maximum in the Lofoten gyre to peak cell densities around the island Jan Mayen in fall. Vertical mixing of Atlantic waters west of Lofoten Island, a phenomenom related to pervasive summer large scale atmospheric changes in the eastern Nordic Seas, on one hand, and strengthened influence of melt-water and related surface water stratification around the island Jan Mayen during fall, on the other hand, explains the observed seasonal migration of the E. huxleyi peak production area, as well as the seasonal change in dominating species within the Iceland Sea. In addition our datasets are indicative of a well-defined maximum boundary temperature of 6 °C for the production of C. pelagicus in the northern North Atlantic. The Fram Strait transects provides, to our knowledge, a first view of the zonal distribution of extant coccolithophores in this remote setting during summer and fall. Our datasets are indicative of a seasonal change in the species community from an E. huxleyi-dominated assemblage during summer to a C. pelagicus-rich population during fall. Here, higher irradiance and increased Atlantic water influence during summer favored the production of the opportunistic species E. huxleyi close to the Arctic Front, whereas the peak production area during fall, with high concentrations of C. pelagicus, lays in true Arctic/Polar waters.

  14. Rock Physical study on an Upper-Palaeozoic Chert and Carbonate Interval in Wells from the Eastern Norwegian Barents Sea.

    NASA Astrophysics Data System (ADS)

    Colpaert, A.; Mienert, J.; Fotland, B.

    2004-12-01

    Due to their general interest as hydrocarbon reservoir, the Upper Palaeozoic chert and carbonate interval in the Norwegian Barents Sea has been investigated from seismic data and well logs. We established a framework for geophysical well log analysis and reservoir characterization for the Finnmark Platform, an area situated in the South-Eastern part of the Norwegian Barents Sea. The interval is composed by approximately 600 m carbonate facies covered by a 60 m interval of spiculitic chert facies. The carbonate facies is characterized by lateral and vertical lithological variations including limestones, dolomites, evaporites and clastic material. The spiculitic interval exists in spiculitic chert and clay alternated with limestones. Data extends over an area with different palaeo environments from inner platform settings to continental slope and even basinal settings. Log curve data from four wells were processed through geophysical well log analysis using Powerlog and Matlab. Multi-well trend analysis was performed for a diagnostic modeling of the rock physical parameters. The examination of the variation of petrophysical properties, and how that variation transfers into the elastic domain is a key to the correlation of rock properties and the seismic attribute information. The final goal is to improve porosity and mineralogy predictions in pseudo-wells from 3D seismic data. The analyses of cross plots allow distinguishing several intervals which in certain cases correspond to individual stratigraphic units. The spiculite interval shows for example different rock types based on rock physics and these parameters can be linked with seismic. For the synthetic seismogram an s-wave velocity log has been modeled. We observed that for several lithological intervals such as the mixed limestone-dolomites and spiculites the Greenberg-Castagna model fitted the best, but for pure dolomite intervals the Krief model is more accurate. Furthermore, for the purest limestone the best fit was obtained for the differential effective medium equations. These intervals should be treated differently for obtaining the best fitting velocity-porosity relations.

  15. Diet among oil-workers on off-shore oil installations in the Norwegian sector of the North Sea.

    PubMed

    Oshaug, A; Ostgård, L I; Trygg, K U

    1992-07-01

    Dietary studies based on 24 h recalls were carried out on four oil installations in the Norwegian sector of the North Sea. Two hundred and three persons were interviewed about what they had eaten the previous 24 h. Food purchased for the installations in the previous 5 months was recorded. Results based on 24 h recalls showed that average daily intake of energy was 12.2 MJ of which 17% came from protein, 44% from fat and 39% from carbohydrate, including 8% from sugar. Meat, vegetables, fresh fruits, seafood (shellfish), french fries, eggs, cream and ice-cream were important components of the diet, while bread, fish and cereals played a minor role. Average daily intake (mg) of nutrients were: calcium 1244, iron 15, vitamin A 1049 micrograms, vitamin D 4.1 micrograms, thiamin 1.6, riboflavin 2.2, nicotinic acid 22, ascorbic acid 143. Dietary fibre intake, estimated as unavailable carbohydrate, was on average 19 g, and the average daily intake of cholesterol was 755 mg. Intakes were compared with the Norwegian recommended dietary allowance. Most of the employees chose a diet which when eaten over a longer period of time may contribute to the development of coronary heart diseases (CHD) and thereby increase the morbidity and mortality from CHD in the oil industry. PMID:1390597

  16. Satellite monitoring temperature conditions spawning area of the Northeast Arctic cod in the Norwegian Sea and assessment its abundance

    NASA Astrophysics Data System (ADS)

    Vanyushin, George; Bulatova, Tatiana; Klochkov, Dmitriy; Troshkov, Anatoliy; Kruzhalov, Michail

    2013-04-01

    In this study, the attempt to consider the relationship between sea surface anomalies of temperature (SST anomalies °C) in spawning area of the Norwegian Arctic cod off the Lofoten islands in coastal zone of the Norwegian Sea and modern cod total stock biomass including forecasting assessment of future cod generation success. Continuous long-term database of the sea surface temperature (SST) was created on the NOAA satellites data. Mean monthly SST and SST anomalies are computed for the selected area on the basis of the weekly SST maps for the period of 1998-2012. These maps were plotted with the satellite SST data, as well as information of vessels, byoies and coastal stations. All data were classified by spawning seasons (March-April) and years. The results indicate that poor and low middle generations of cod (2001, 2006, 2007) occurred in years with negative or extremely high positive anomalies in the spawning area. The SST anomalies in years which were close to normal or some more normal significances provide conditions for appearance strong or very strong generations of cod (1998, 2000, 2002, 2004, 2005, 2006, 2008, 2009). Temperature conditions in concrete years influence on different indexes of cod directly. So, the mean temperature in spawning seasons in years 1999-2005 was ≈5,0°C and SST anomaly - +0,35°C, by the way average year significances indexes of cod were: total stock biomass - 1425,0 th.t., total spawning biomass - 460,0 th.t., recruitment (age 3+) - 535,0 mln. units and landings - 530,0 th.t. In spawning seasons 2006-2012 years the average data were following: mean SST ≈6,0°C, SST anomaly - +1,29°C, total stock biomass - 2185,0 th.t., total spawning biomass - 1211,0 th.t., recruitment (age 3+) - 821,0 mln. units and landings - 600,0 th.t. The SST and SST anomalies (the NOAA satellite data) characterize increase of decrease in input of warm Atlantic waters which form numerous eddies along the flows of the main warm currents thus creating favorable conditions for development of the cod larvae and fry and provide them with food stock, finally, direct influence on forming total stock biomass of cod and helping its population forecast. Key words: satellite monitoring of SST, Northeast Arctic cod, spawning area, maps of SST, prognosis.

  17. Iodine-129 Time Series in Danish, Norwegian and Northwest Greenland Coast and the Baltic Sea by Seaweed

    NASA Astrophysics Data System (ADS)

    Hou, X. L.; Dahlgaard, H.; Nielsen, S. P.

    2000-11-01

    The concentrations of 129I and 127I were determined in archived time series seaweed samples from Klint in the Kattegat, Bornholm in the Baltic Sea, Roskilde Fjord in Zealand of Denmark, Utsira in the western Norwegian coast and NW Greenland by neutron activation analysis. The results indicate that the 129I levels in all locations investigated are one to three orders of magnitude higher than the fall-out background and strongly dominated by the discharges from reprocessing facilities at La Hague and Sellafield. The 129I/ 99Tc ratio is applied to estimate the origin of and transit times of 129I. Transit times of 129I are estimated to be 1-2 years from La Hague to Klint and Utsira and 9-14 years to NW Greenland. Transfer factors of 129I are calculated to be 54 yr m -3from La Hague to Klint, 60 yr m -3to Utsira and 1·2 yr m -3to NW Greenland. Based on the estimated transit times, transfer factors and annual discharge data of radionulides from the reprocessing facilities, the variations of 129I concentrations and 129I/ 99Tc and 129I/ 137Cs ratios are modelled. Except 129I/ 137Cs, others are in a good agreement between the modelled and measured values.

  18. Barite and barium in sediments and coral skeletons around the hydrocarbon exploration drilling site in the Trna Deep, Norwegian Sea

    NASA Astrophysics Data System (ADS)

    Lepland, Aivo; Mortensen, Pl Buhl

    2008-11-01

    Barite and barium concentrations in bottom sediments and coral skeletons from the vicinity of the hydrocarbon exploration well drilled in 1992 1993 in the Trna Deep, Norwegian Sea have been studied to assess the spreading of the drilling mud and related ecological effects on Lophelia petrusa coral reefs. Sand size barite crystals derived from the drilling mud and elevated Ba concentrations in surface (0 2 cm) sediments were found up to 4 km from the exploration drilling site. 210Pb-dating results on sediment cores indicate that Ba-rich surface intervals (0 2 cm) record ca. 20 years of sedimentation history, and connect Ba enrichment with exploration drilling. The geographic distribution of Ba contents in sediments allowed the reconstruction of the drilling mud dispersal pattern showing transport eastward from the drilling site, consistent with the prevailing current directions. The presence of relatively coarse-grained sediments and barite crystals trapped in coral polyps, ca. 500 m down current from the drilling site, reflects the elevated turbulence and sediment supply during the drilling activity. This elevated sediment dispersion likely placed a stress upon the coral reefs, but due to strong currents that effectively dilute episodic drilling waste and sediment discharges, the damage does not appear significant.

  19. Distribution of anaerobic methane-oxidizing and sulfate-reducing communities in the G11 Nyegga pockmark, Norwegian Sea.

    PubMed

    Lazar, Cassandre Sara; Dinasquet, Julie; L'Haridon, Stéphane; Pignet, Patricia; Toffin, Laurent

    2011-11-01

    Pockmarks are seabed geological structures sustaining methane seepage in cold seeps. Based on RNA-derived sequences the active fraction of the archaeal community was analysed in sediments associated with the G11 pockmark, in the Nyegga region of the Norwegian Sea. The anaerobic methanotrophic Archaea (ANME) and sulfate-reducing bacteria (SRB) communities were studied as well. The vertical distribution of the archaeal community assessed by PCR-DGGE highlighted the presence of ANME-2 in surface sediments, and ANME-1 in deeper sediments. Enrichments of methanogens showed the presence of hydrogenotrophic methanogens of the Methanogenium genus in surface sediment layers as well. The active fraction of the archaeal community was uniquely composed of ANME-2 in the shallow sulfate-rich sediments. Functional methyl coenzyme M reductase gene libraries showed that sequences affiliated with the ANME-1 and ANME-3 groups appeared in the deeper sediments but ANME-2 dominated both surface and deeper layers. Finally, dissimilatory sulfite reductase gene libraries revealed a high SRB diversity (i.e. Desulfobacteraceae, Desulfobulbaceae, Syntrophobacteraceae and Firmicutes) in the shallow sulfate-rich sediments. The SRB diversity was much lower in the deeper section. Overall, these results show that the microbial community in sediments associated with a pockmark harbour classical cold seep ANME and SRB communities. PMID:21751028

  20. Petroleum migration, alteration, and remigration within Troll field, Norwegian North Sea

    SciTech Connect

    Horstad, I.; Larter, S.R.

    1997-02-01

    Troll field represents the largest petroleum discovery within the entire North Sea area in oil equivalents, with 74% of the accumulated petroleum present as dry gas and 26% as a heavy biodegraded oil leg. The field is divided into several provinces based on the distribution of gas and oil, and the gas and oil have been suggested to be cogenetic. The migration and filling model presented in this paper suggests that the oil and gas represent two different migration phases and that gas migration and filling predate oil emplacement. Two different oil populations have been characterized and mapped in Troll field applying conventional geochemical techniques. We suggest that the two oil populations migrated into the structure through two different migration systems. Oil and gas were subsequently biodegraded within the reservoir. The two oil populations have been found in neighboring oil and gas discoveries, and an oil-oil correlation with these discoveries has been used to determine the location of field filling points and regional migration routes. When oil biodegradation terminated, fresh oil continued to migrate into the reservoir and mixed with the residue of the biodegraded oil. The field was tilted downward to the west in the Neogene, and oil and gas remigrated within the field with a possible spillage of gas. Tilting resulted in a dominantly upward movement of the oil phase whereas gas migrated laterally. Residual oils in the water zone have been used to reconstruct the paleoconfiguration of the field that controlled the current distribution of oil populations within Troll field.

  1. Contemporary ocean warming and freshwater conditions are related to later sea age at maturity in Atlantic salmon spawning in Norwegian rivers.

    PubMed

    Otero, Jaime; Jensen, Arne J; L'abée-Lund, Jan Henning; Stenseth, Nils Chr; Storvik, Geir O; Vøllestad, Leif Asbjørn

    2012-09-01

    Atlantic salmon populations are reported to be declining throughout its range, raising major management concerns. Variation in adult fish abundance may be due to variation in survival, growth, and timing of life history decisions. Given the complex life history, utilizing highly divergent habitats, the reasons for declines may be multiple and difficult to disentangle. Using recreational angling data of two sea age groups, one-sea-winter (1SW) and two-sea-winter (2SW) fish originated from the same smolt year class, we show that sea age at maturity of the returns has increased in 59 Norwegian rivers over the cohorts 1991-2005. By means of linear mixed-effects models we found that the proportion of 1SW fish spawning in Norway has decreased concomitant with the increasing sea surface temperature experienced by the fish in autumn during their first year at sea. Furthermore, the decrease in the proportion of 1SW fish was influenced by freshwater conditions as measured by water discharge during summer months 1 year ahead of seaward migration. These results suggest that part of the variability in age at maturity can be explained by the large-scale changes occurring in the north-eastern Atlantic pelagic food web affecting postsmolt growth, and by differences in river conditions influencing presmolt growth rate and later upstream migration. PMID:23139878

  2. Noise exposure of commercial divers in the Norwegian Sector of the North Sea.

    PubMed

    Nedwell, J R; Mason, T I; Collett, A G; Gardiner, R W K

    2015-01-01

    It is well known that exposure to high noise levels can adversely affect human hearing. Legislation exists in Europe to control or restrict the level of noise to which employees may be exposed during the course of their work. While the noise levels to which a worker may be exposed is well defined in air, human sensitivity to noise is different in high-pressure and mixed-gas conditions. Relatively little research exists to define human hearing in these circumstances, and few measurements exist of the levels of noise to which divers working in these conditions are exposed. A study using specially designed equipment has been undertaken in Norwegian waters to sample the noise levels present during typical saturation dives undertaken by commercial divers working in the Norwegian oil and gas industry. The divers were working in heliox at depths of 30 msw and 120 msw. It found noise levels were generally dominated by self-noise: flow noise while breathing and communications. The noise levels, both when corrected for the difference in hearing sensitivity under pressure in mixed gas and uncorrected, would exceed legislated limits for noise exposure in a working day without the use of noisy tools. PMID:26094290

  3. Fault growth and interactions in a multiphase rift fault network: Horda Platform, Norwegian North Sea

    NASA Astrophysics Data System (ADS)

    Duffy, Oliver B.; Bell, Rebecca E.; Jackson, Christopher A.-L.; Gawthorpe, Rob L.; Whipp, Paul S.

    2015-11-01

    Physical models predict that multiphase rifts that experience a change in extension direction between stretching phases will typically develop non-colinear normal fault sets. Furthermore, multiphase rifts will display a greater frequency and range of styles of fault interactions than single-phase rifts. Although these physical models have yielded useful information on the evolution of fault networks in map view, the true 3D geometry of the faults and associated interactions are poorly understood. Here, we use an integrated 3D seismic reflection and borehole dataset to examine a range of fault interactions that occur in a natural multiphase fault network in the northern Horda Platform, northern North Sea. In particular we aim to: i) determine the range of styles of fault interaction that occur between non-colinear faults; ii) examine the typical geometries and throw patterns associated with each of these different styles; and iii) highlight the differences between single-phase and multiphase rift fault networks. Our study focuses on a ca. 350 km2 region around the >60 km long, N-S-striking Tusse Fault, a normal fault system that was active in the Permian-Triassic and again in the Late Jurassic-to-Early Cretaceous. The Tusse Fault is one of a series of large (>1500 m throw) N-S-striking faults forming part of the northern Horda Platform fault network, which includes numerous smaller (2-10 km long), lower throw (<100 m), predominantly NW-SE-striking faults that were only active during the Late Jurassic to Early Cretaceous. We examine how the 2nd-stage NW-SE-striking faults grew, interacted and linked with the N-S-striking Tusse Fault, documenting a range of interaction styles including mechanical and kinematic isolation, abutment, retardation and reactivated relays. Our results demonstrate that: i) isolated, and abutting interactions are the most common fault interaction styles in the northern Horda Platform; ii) pre-existing faults can act as sites of nucleation for 2nd-stage faults or may form mechanical barriers to propagation; iii) the throw distribution on reactivated 1st-stage faults will be modified in a predictable manner if they are intersected or influenced by 2nd-stage faults; iv) sites of fault linkage and relay-breaching associated with the first phase of extension can act as preferential nucleation sites for 2nd-stage faults; and v) the development of fault intersections is a dynamic process, involving the gradual transition from one style to another.

  4. Summer distribution and ecological role of seabirds and marine mammals in the Norwegian and Greenland seas (June 1988)

    NASA Astrophysics Data System (ADS)

    Joiris, Claude R.

    1992-03-01

    During the ARK V /2 expedition of RV Polarstern in the Norwegian and Greenland seas in June 1988, 380 half hour counts for marine vertebrates (seabirds, pinnipeds and cetaceans) were carried out. Results are presented as total numbers encountered and then converted into density and food intake. Mean food intake was 2.2 kg fresh weight per km 2 per day for seabirds, with a higher value in Atlantic water (2.5) lower values in polar water and the pack ice (1.7 and 1.9), and an intermediate value at the ice edge. The main species were the alcids (1.5, primarily Little Auk, Alle alle and Brünnich's Guillemot, Urea Iomvia) ,the Fulmar, Fulmarus glacialis (0.5), and the Kittiwake, Rissa tridactyla (0.2). The ecological role of cetaceans was clearly lower, with a mean value of 0.2 and a maximum of 0.7 in Atlantic water (rough evaluation, due to the low number of contacts). The food intake by pinnipeds was 0.55 kg/km 2 day at the ice edge and 0.4 in the pack ice; they were mainly harp, Phoca groenlandica and hooded seals, Cystophora cristata, in one main concentration each and ringed seals, Phoca hispida, scattered on the pack. Data for July 1988 show a great similarity with these results, except for a lower density of alcids, which probably reflects that Little Auk, Brünnich's Guillemot and Common Guillemot, Uria aalge already had started to leave the region.

  5. Bering Sea

    NASA Technical Reports Server (NTRS)

    2002-01-01

    The skies of the Bering Sea were relatively clear again in this SeaWiFS image showing a band of aquamarine colored water. Credit: Provided by the SeaWiFS Project, NASA/Goddard Space Flight Center, and ORBIMAGE

  6. Bering Sea

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Much of the Bering Sea is clear in this SeaWiFS image. The large expanse of bright aquamarine water is clearly visible. Credit: Provided by the SeaWiFS Project, NASA/Goddard Space Flight Center, and ORBIMAGE

  7. Red Sea

    Atmospheric Science Data Center

    2013-04-16

    article title:  The Red Sea     View Larger Image ... Multi-angle Imaging SpectroRadiometer (MISR) image of the Red Sea was acquired on August 13, 2000. Located between the East African coast and the Saudi Arabian peninsula, the Red Sea got its name because the blooms of a type of algae,  Trichodesmium ...

  8. Autophagy at sea.

    PubMed

    Martens, Sascha; Rusten, Tor Erik; Kraft, Claudine

    2013-09-01

    The 3rd EMBO Conference on, "Autophagy: Molecular mechanism, physiology and pathology" organized by Anne Simonsen and Sharon Tooze, was held in May 2013 on a sea cruise along the Norwegian coastline from Bergen to Tromsø. Researchers from all corners of the world presented work covering autophagosome biogenesis, physiological regulation of autophagy, selective autophagy and disease. PMID:23917436

  9. Reconstructing coastal environmental condition in the eastern Norwegian Sea by means of Arctica islandica sclerochronological records

    NASA Astrophysics Data System (ADS)

    Trofimova, Tamara; Andersson, Carin

    2015-04-01

    Paleo archives are fundament in improving our knowledge of the natural climate variability. Established marine proxy records for the ocean, especially for high latitudes, are both sparsely distributed and are poorly resolved in time. The identification and development of new archives and proxies for studying key ocean processes at annual to sub-annual resolution that can extend the marine instrumental record is therefore a clear priority for marine climate science. The bivalve species Arctica islandica is a unique paleoclimatic archive with an exceptional longevity combined with high temporal resolution, due to accretion of annual growth increments. The aim of this study is to use sclerochronological records of A. islandica to extend instrumental hydrographic records and increase our understanding of a variability of a Norwegian Coastal Current (NCC). The NCC transports warm, low-salinity water northwards, which eventually plays role for the Arctic halocline. Moreover, previous investigations showed the connection of properties and variability of the NCC with catches of commercially valuable fishes. The knowledge of the variability of the NCC is also essential for possible future prediction climate conditions and fish stock variability in the region. In this study we use shells of Arctica islandica collected off the coast of Eggum (Lofoten, Norway). The material was obtained from the depth 5-10 m by dredging along the seabed and by means of scuba divers. We examine the growth patterns of living and subfossil shells. Ongoing work mainly focuses on the construction of a composite growth chronology based on increment-width time series. The results we will compare with existing time series of the environment and climatic parameters to determine the controlling factors and test the applicability of growth chronology in a climate reconstruction. Furthermore, we will perform geochemical analyses of the stable isotope composition (δ18O and δ13C) in shell carbonate to identify seasonal signals and reconstruct the surface water temperature on a sub-annual time-scale.

  10. Velocity Modelling Results Of A Pockmark In The Nyegga Region, Norwegian Sea

    NASA Astrophysics Data System (ADS)

    Jose, T.; Minshull, T.; Westbrook, G.; Nouzé, H.; Ker, S.; Exley, R.; Gailler, A.; Berndt, C.

    2008-12-01

    Pockmarks are a common indicator of fluid flow through the seafloor at continental margins. They are thought to be of global significance as pathways for the escape of methane from the sediments to the water column beneath continental margins, and also as habitats for chemosynthetic communities of biota. Their mechanism of formation and internal dynamics remain poorly constrained, partly due to a lack of proper three dimensional imaging of their internal structure. Numerous fluid escape features provide evidence for an active fluid-flow system in the Nyegga region of the Norwegian continental margin. In June-July 2006 we conducted a high-resolution seismic experiment using ocean bottom seismometers (OBS) to investigate the detailed 3D structure of a 250-m-wide pockmark in this region, named G11 and hence to determine the distribution of gas and gas hydrate in and around the pockmark . An array of 14 OBS were deployed across the pockmark. Shots fired from two 35 cu. in. mini GI guns were recorded on these OBS and on a near surface hydrophone streamer. Shot and OBS locations were determined with c. 1 m uncertainty using water wave arrivals. The OBS and reflection data reveal many interesting features of the subsurface geology of the chimney. A group of bright reflectors underlies the pockmark at a travel time of c. 1.4 s and at deeper depths some of the reflectors show strong attenuation indicating the presence of gas in the sediments. A pipe ascends from this gas charged zone to where it terminates in the investigated G11 pockmark. We have analysed data from five OBS lying along a line running NE-SW across the pockmark, using both raytracing and reflection tomography. The raytraced forward model, which incorporates signals from six subsurface reflectors, shows, a gradual increase in velocity between the seafloor and the gas charged zone, lying c. 300 m depth below the seabed. The travel-time fit is improved significantly if velocities in the pipe beneath the pockmark are higher than those in the surrounding sediments. The maximum velocity anomaly is c. 6%. An initial tomographic inversion using signals from a single subsurface reflector at the top of the gas-charged zone also recovers a velocity anomaly of c. 6%. This velocity anomaly may be attributed to the presence of increased saturations of methane hydrate beneath the pockmark.

  11. Thermogenic degassing of methane during the PETM: Geochemical and palynological constrains from a borehole in the Norwegian Sea

    NASA Astrophysics Data System (ADS)

    Planke, Sverre; Svensen, Henrik; Frieling, Joost; Sluijs, Appy

    2015-04-01

    Emplacement of voluminous magmatic sills in sedimentary basins around the NE Atlantic led to widespread thermogenic gas generation in contact aureoles. Kilometer-sized degassing pipes and craters, termed hydrothermal vent complexes, are identified on seismic data and believed to have played a key role in releasing methane to the atmosphere and thus triggering of the Paleocene-Eocene Thermal Maximum (PETM). However, the link between pipe degassing and the PETM is questioned due to lack of accurate time constraints on degassing and crater formation. We present new geochemical and palynological data from a 3521 m deep petroleum exploration well, 6607/12-1, drilled through the center of a hydrothermal vent complex in the Vøring basin, the Norwegian Sea. We have undertaken a comprehensive sampling and analytical program of the cuttings from the well to study the age, formation and implications of the hydrothermal vent complex from this unique locality. Based on our results, we have divided the hydrothermal vent complex in four main zones: 1) a high temperature lower conduit (3521-2100 m), 2) an upper conduit (2100-1725 m), 3) crater deposits (1725-1590 m), and 4) seep carbonates (1510-1380 m). The crater is identified as a 2 km wide semi-circular eye-structure on the seismic data, characterized by low seismic velocities (Vp < 1.8 km/s) and high neutron porosities (>45%). The palynomorphs in the upper conduit have a high Thermal Alteration Index, suggesting heating from ascending fluids. At the base of the crater, the PETM dinocyst marker species Apectodinium augustum is present, thermally altered at the base but immature up-section. This can be explained by ejecta deposits at the base or by a final stage of hydrothermal activity. Carbon isotope analyses on palynomorph fractions shows that the PETM negative carbon isotope excursion (CIE) is present in the 1745-1665 m interval. The core of the PETM CIE is preserved at 1745-1720 m and the recovery stage from 1720-1665 m. The new data shows that the hydrothermal vent complex was formed during the early stage of the PETM and thus corroborates the hypothesis that continued thermogenic degassing was a key player in carbon cycle perturbations that characterize the PETM.

  12. Recovery of benthic megafauna from anthropogenic disturbance at a hydrocarbon drilling well (380 m depth in the Norwegian Sea).

    PubMed

    Gates, Andrew R; Jones, Daniel O B

    2012-01-01

    Recovery from disturbance in deep water is poorly understood, but as anthropogenic impacts increase in deeper water it is important to quantify the process. Exploratory hydrocarbon drilling causes physical disturbance, smothering the seabed near the well. Video transects obtained by remotely operated vehicles were used to assess the change in invertebrate megafaunal density and diversity caused by drilling a well at 380 m depth in the Norwegian Sea in 2006. Transects were carried out one day before drilling commenced and 27 days, 76 days, and three years later. A background survey, further from the well, was also carried out in 2009. Porifera (45% of observations) and Cnidaria (40%) dominated the megafauna. Porifera accounted for 94% of hard-substratum organisms and cnidarians (Pennatulacea) dominated on the soft sediment (78%). Twenty seven and 76 days after drilling commenced, drill cuttings were visible, extending over 100 m from the well. In this area there were low invertebrate megafaunal densities (0.08 and 0.10 individuals m(-2)) in comparison to pre-drill conditions (0.21 individuals m(-2)). Three years later the visible extent of the cuttings had reduced, reaching 60 m from the well. Within this area the megafaunal density (0.05 individuals m(-2)) was lower than pre-drill and reference transects (0.23 individuals m(-2)). There was a significant increase in total megafaunal invertebrate densities with both distance from drilling and time since drilling although no significant interaction. Beyond the visible disturbance there were similar megafaunal densities (0.14 individuals m(-2)) to pre-drilling and background surveys. Species richness, Shannon-Weiner diversity and multivariate techniques showed similar patterns to density. At this site the effects of exploratory drilling on megafaunal invertebrate density and diversity seem confined to the extent of the visible cuttings pile. However, elevated Barium concentration and reduced sediment grain size suggest persistence of disturbance for three years, with unclear consequences for other components of the benthic fauna. PMID:23056177

  13. Recovery of Benthic Megafauna from Anthropogenic Disturbance at a Hydrocarbon Drilling Well (380 m Depth in the Norwegian Sea)

    PubMed Central

    Gates, Andrew R.; Jones, Daniel O. B.

    2012-01-01

    Recovery from disturbance in deep water is poorly understood, but as anthropogenic impacts increase in deeper water it is important to quantify the process. Exploratory hydrocarbon drilling causes physical disturbance, smothering the seabed near the well. Video transects obtained by remotely operated vehicles were used to assess the change in invertebrate megafaunal density and diversity caused by drilling a well at 380 m depth in the Norwegian Sea in 2006. Transects were carried out one day before drilling commenced and 27 days, 76 days, and three years later. A background survey, further from the well, was also carried out in 2009. Porifera (45% of observations) and Cnidaria (40%) dominated the megafauna. Porifera accounted for 94% of hard-substratum organisms and cnidarians (Pennatulacea) dominated on the soft sediment (78%). Twenty seven and 76 days after drilling commenced, drill cuttings were visible, extending over 100 m from the well. In this area there were low invertebrate megafaunal densities (0.08 and 0.10 individuals m−2) in comparison to pre-drill conditions (0.21 individuals m−2). Three years later the visible extent of the cuttings had reduced, reaching 60 m from the well. Within this area the megafaunal density (0.05 individuals m−2) was lower than pre-drill and reference transects (0.23 individuals m−2). There was a significant increase in total megafaunal invertebrate densities with both distance from drilling and time since drilling although no significant interaction. Beyond the visible disturbance there were similar megafaunal densities (0.14 individuals m−2) to pre-drilling and background surveys. Species richness, Shannon-Weiner diversity and multivariate techniques showed similar patterns to density. At this site the effects of exploratory drilling on megafaunal invertebrate density and diversity seem confined to the extent of the visible cuttings pile. However, elevated Barium concentration and reduced sediment grain size suggest persistence of disturbance for three years, with unclear consequences for other components of the benthic fauna. PMID:23056177

  14. Quantifying the ocean, freshwater and human effects on year-to-year variability of one-sea-winter Atlantic salmon angled in multiple Norwegian rivers.

    PubMed

    Otero, Jaime; Jensen, Arne J; L'Abée-Lund, Jan Henning; Stenseth, Nils Chr; Storvik, Geir O; Vøllestad, Leif Asbjørn

    2011-01-01

    Many Atlantic salmon, Salmo salar, populations are decreasing throughout the species' distributional range probably due to several factors acting in concert. A number of studies have documented the influence of freshwater and ocean conditions, climate variability and human impacts resulting from impoundment and aquaculture. However, most previous research has focused on analyzing single or only a few populations, and quantified isolated effects rather than handling multiple factors in conjunction. By using a multi-river mixed-effects model we estimated the effects of oceanic and river conditions, as well as human impacts, on year-to-year and between-river variability across 60 time series of recreational catch of one-sea-winter salmon (grilse) from Norwegian rivers over 29 years (1979-2007). Warm coastal temperatures at the time of smolt entrance into the sea and increased water discharge during upstream migration of mature fish were associated with higher rod catches of grilse. When hydropower stations were present in the course of the river systems the strength of the relationship with runoff was reduced. Catches of grilse in the river increased significantly following the reduction of the harvesting of this life-stage at sea. However, an average decreasing temporal trend was still detected and appeared to be stronger in the presence of salmon farms on the migration route of smolts in coastal/fjord areas. These results suggest that both ocean and freshwater conditions in conjunction with various human impacts contribute to shape interannual fluctuations and between-river variability of wild Atlantic salmon in Norwegian rivers. Current global change altering coastal temperature and water flow patterns might have implications for future grilse catches, moreover, positioning of aquaculture facilities as well as the implementation of hydropower schemes or other encroachments should be made with care when implementing management actions and searching for solutions to conserve this species. PMID:21897867

  15. Quantifying the Ocean, Freshwater and Human Effects on Year-to-Year Variability of One-Sea-Winter Atlantic Salmon Angled in Multiple Norwegian Rivers

    PubMed Central

    Otero, Jaime; Jensen, Arne J.; L'Abée-Lund, Jan Henning; Stenseth, Nils Chr.; Storvik, Geir O.; Vøllestad, Leif Asbjørn

    2011-01-01

    Many Atlantic salmon, Salmo salar, populations are decreasing throughout the species' distributional range probably due to several factors acting in concert. A number of studies have documented the influence of freshwater and ocean conditions, climate variability and human impacts resulting from impoundment and aquaculture. However, most previous research has focused on analyzing single or only a few populations, and quantified isolated effects rather than handling multiple factors in conjunction. By using a multi-river mixed-effects model we estimated the effects of oceanic and river conditions, as well as human impacts, on year-to-year and between-river variability across 60 time series of recreational catch of one-sea-winter salmon (grilse) from Norwegian rivers over 29 years (1979–2007). Warm coastal temperatures at the time of smolt entrance into the sea and increased water discharge during upstream migration of mature fish were associated with higher rod catches of grilse. When hydropower stations were present in the course of the river systems the strength of the relationship with runoff was reduced. Catches of grilse in the river increased significantly following the reduction of the harvesting of this life-stage at sea. However, an average decreasing temporal trend was still detected and appeared to be stronger in the presence of salmon farms on the migration route of smolts in coastal/fjord areas. These results suggest that both ocean and freshwater conditions in conjunction with various human impacts contribute to shape interannual fluctuations and between-river variability of wild Atlantic salmon in Norwegian rivers. Current global change altering coastal temperature and water flow patterns might have implications for future grilse catches, moreover, positioning of aquaculture facilities as well as the implementation of hydropower schemes or other encroachments should be made with care when implementing management actions and searching for solutions to conserve this species. PMID:21897867

  16. Effects of bottom water warming and sea level rise on Holocene hydrate dissociation and mass wasting along the Norwegian-Barents Continental Margin

    NASA Astrophysics Data System (ADS)

    Jung, Woo-Yeol; Vogt, Peter R.

    2004-06-01

    Gas hydrate (GH) stability modeling results explain why some major Holocene submarine landslides along the Norwegian-Barents margin could have been triggered by GH dissociation during the early to middle Holocene, not during the lowest sea levels of the Last Glacial Maximum (LGM). Our model results show that subbottom depths of 170-260 m below the pre-slide continental slope (ca. 350-475 m present water depth) must have passed out of gas hydrate stability zone (GHSZ) by 8.15 ka as the effect of warm bottom water inflow at 11 ka penetrated into the subbottom, overcoming the effects of pressure increase due to sea level rise (SLR). The component of local SLR due to the isostatic response to Fennoscandian deglaciation is shown to be relatively insignificant, particularly for the part of the upper continental slope where the slide probably began. The stability relations show that GH could have formed under the ice sheet before deglaciation, and below deeper shelf areas after sea levels began to rise, but before significant warming near the GHSZ base. To the extent water deeper than 800 m has remained cold (-1° to 0°C) since LGM times, the GHSZ continued to thicken in deep water and GH dissociation could not have triggered Holocene failure in that regime. The present distribution of GH stability is limited to water depths greater than about 400 m in the Storegga slide area, and the thickness of the GHSZ increases with water depth.

  17. The genesis of sea level variability in the Barents Sea

    NASA Astrophysics Data System (ADS)

    Volkov, Denis L.; Landerer, Felix W.; Kirillov, Sergey A.

    2013-09-01

    The regional variability of sea level is an integral indicator of changing oceanographic conditions due to different processes of oceanic, atmospheric, and terrestrial origin. The present study explores the nature of sea level variability in the Barents Sea-a marginal shelf sea of the Arctic Ocean. A characteristic feature that distinguishes this sea from other Arctic shelf seas is that it is largely ice free throughout the year. This allows continuous monitoring of sea level by space-borne altimeters. In this work we combine satellite altimetry, ocean gravity measurements by GRACE satellites, available hydrography data, and a high-resolution ocean data synthesis product to estimate the steric and mass-related components of sea level in the Barents Sea. We present one of the first observational evidence of the local importance of the mass-related sea level changes. The observed 1-3 month phase lag between the annual cycles of sea level in the Barents Sea and in the Nordic seas (Norwegian, Iceland, Greenland seas) is explained by the annual mass-related changes. The analysis of the barotropic vorticity budget shows that the mass-related sea level variability in the central part of the Barents Sea is determined by the combined effect of wind stress, flow over the varying bottom topography, and dissipation, while the impact of vorticity fluxes is negligible. Overall, the steric sea level has smaller amplitudes and mainly varies on the seasonal time scale. The thermosteric sea level is the main contributor to the steric sea level along the pathways of the Atlantic inflow into the Barents Sea. The relative contribution of the halosteric sea level is dominant in the southeastern, eastern, and northern parts of the Barents Sea, modulated by the seasonal sea ice formation/melt as well as by continental runoff. The variability of the thermosteric sea level in the Barents Sea is mostly driven by variations in the net surface heat flux, whereas the contribution of heat advection becomes as important as the ocean-atmosphere heat exchange at interannual time scales.

  18. A cold air outbreak over the Norwegian Sea observed with the Tiros-N Operational Vertical Sounder (TOVS) and the Special Sensor Microwave/Imager (SSM/I)

    NASA Technical Reports Server (NTRS)

    Claud, Chantal; Katsaros, Kristina B.; Petty, Grant W.; Chedin, Alain; Scott, Noelle A.

    1992-01-01

    Until recently, the scarcity of meteorological observations over polar areas has limited studies of high latitude weather systems, but now data from polar orbiting satellites offer a new opportunity to observe and describe these systems. TOVS data were used successfully for delineating synoptic and subsynoptic systems since they provide the vertical temperature structure of the atmosphere: SSM/I observations have proved valuable for analyzing storms through water vapor and rain determinations. These positive results prompted us to analyze simultaneous TOVS and SSM/I observations obtained during a cold air outbreak over the Norwegian Sea. After a description of the instruments and the retrieval schemes, the mutually supporting information from these two independent instruments is discussed. Implications for the monitoring of polar lows are presented.

  19. A cold air outbreak over the Norwegian Sea observed with the Tiros-N Operational Vertical Sounder (TOVS) and the Special Sensor Microwave/Imager (SSM/I)

    NASA Technical Reports Server (NTRS)

    Claud, Chantal; Katsaros, Kristina B.; Petty, Grant W.; Chedin, Alain; Scott, Noelle A.

    1992-01-01

    Until recently, the scarcity of meteorological observations over polar areas has limited studies of high-latitude weather systems, but now data from polar orbiting satellites offer a new opportunity to observe and describe these systems. TOVS data have been used successfully for delineating synoptic and subsynoptic systems, since they provide the vertical temperature structure of the atmosphere; SSM/I observations have proved valuable for analyzing storms through water vapor and rain determinations. These positive results prompted simultaneous analysis of TOVS and SSM/I observations obtained during a cold air outbreak over the Norwegian Sea. After a description of the instruments and the retrieval schemes, the mutually supporting information from these two independent instruments is discussed. Implications for the monitoring of polar lows are presented.

  20. Sea Legs

    NASA Astrophysics Data System (ADS)

    Macdonald, Kenneth C.

    Forty-foot, storm-swept seas, Spitzbergen polar bears roaming vast expanses of Arctic ice, furtive exchanges of forbidden manuscripts in Cold War Moscow, the New York city fashion scene, diving in mini-subs to the sea floor hot srings, life with the astronauts, romance and heartbreak, and invading the last bastions of male exclusivity: all are present in this fast-moving, non-fiction account of one woman' fascinating adventures in the world of marine geology and oceanography.

  1. Satellite observations of a polar low over the Norwegian Sea by Special Sensor Microwave Imager, Geosat, and TIROS-N Operational Vertical Sounder

    NASA Technical Reports Server (NTRS)

    Claud, Chantal; Mognard, Nelly M.; Katsaros, Kristina B.; Chedin, Alain; Scott, Noelle A.

    1993-01-01

    Many polar lows are generated at the boundary between sea ice and the ocean, in regions of large temperature gradients, where in situ observations are rare or nonexistent. Since satellite observations are frequent in high-latitude regions, they can be used to detect polar lows and track their propagation and evolution. The Special Sensor Microwave/Imager (SSM/I) providing estimates of surface wind speed, integrated cloud liquid water content, water vapor content, and precipitation size ice-scattering signal over the ocean; the Geosat radar altimeter measuring surface wind speed and significant wave height; and the TIROS-N Operational Vertical Sounder (TOVS) allowing the determination of temperature and humidity profiles in the atmosphere have been used in synergy for a specific case which occurred in the Norwegian Sea on January, 23-24 1988. All three instruments show sharp atmospheric gradients associated with the propagation of this low across the ocean, which permit the detection of the polar low at a very early stage and tracking it during its development, propagation, and decay. The wind speed gradients are measured with good qualitative agreement between the altimeter and SSM/I. TOVS retrieved fields prior to the formation of the low confirm the presence of an upper level trough, while during the mature phase baroclinicity can be observed in the 1000-500 hPa geopotential thicknesses.

  2. Sea Ice

    NASA Technical Reports Server (NTRS)

    Perovich, D.; Gerland, S.; Hendricks, S.; Meier, Walter N.; Nicolaus, M.; Richter-Menge, J.; Tschudi, M.

    2013-01-01

    During 2013, Arctic sea ice extent remained well below normal, but the September 2013 minimum extent was substantially higher than the record-breaking minimum in 2012. Nonetheless, the minimum was still much lower than normal and the long-term trend Arctic September extent is -13.7 per decade relative to the 1981-2010 average. The less extreme conditions this year compared to 2012 were due to cooler temperatures and wind patterns that favored retention of ice through the summer. Sea ice thickness and volume remained near record-low levels, though indications are of slightly thicker ice compared to the record low of 2012.

  3. Black Sea

    NASA Technical Reports Server (NTRS)

    2002-01-01

    The Black Sea in eastern Russia is experiencing an ongoing phytoplankton bloom. This image, the most recent in a series that began in early may, shows the waters to be even more colorful than before. part of the increased brightness may be due to the presence of sun glint , especially in the center of the sea. However, more organisms appear to be present as well, their photosynthetic pigments reflecting different wavelengths of light.This Moderate Resolution Imaging Spectroradiometer (MODIS) image was captured on June 15, 2002.

  4. Sea ice in the China Sea

    SciTech Connect

    Deng Shuqi

    1993-12-31

    In every winter, sea ice occurring in Bohai Sea and the North Yellow Sea is the first-year ice which is going through generating, developing and thawing processes. Therefore, it is necessary to spatially and temporally describe ice period, freezing range, thickness variations and general motion of sea ice. The purpose of this paper is to provide initial general situation and features of sea ice for forecasting and researching sea ice.

  5. Aral Sea

    Atmospheric Science Data Center

    2013-04-16

    ... The retreating shoreline leaves the surface encrusted with salt and with agrochemicals brought in by the rivers. As the Sea's moderating ... Large Aral, and may be associated with windblown snow and/or salt particles carried aloft. The Multi-angle Imaging SpectroRadiometer ...

  6. Ross Sea

    Atmospheric Science Data Center

    2013-04-16

    article title:  Icebergs in the Ross Sea     View Larger Image Two large icebergs, designated B-15A and C-16, are captured in this Multi-angle Imaging ... the longitudinal quadrant in which it is first seen, and new icebergs sighted in that quadrant are sequentially numbered. B-15 divided from ...

  7. From Sea to Shining Sea

    ERIC Educational Resources Information Center

    Scott, Beverly

    2005-01-01

    Deep down in the depths of the sea, beautiful fish, mysterious ocean life, and unusual plants glimmer and glow in the eerie atmosphere of an ever-changing ocean. This article describes how, with this vision and a purpose in mind, three teachers pulled open classroom walls and joined forces so their second graders could create a mammoth 30 x 75"…

  8. Steric height variability in the Nordic Seas

    NASA Astrophysics Data System (ADS)

    Siegismund, F.; Johannessen, J.; Drange, H.; Mork, K. A.; Korablev, A.

    2007-12-01

    The variability of steric height in the Nordic Seas is analyzed on seasonal, interannual, and decadal timescales using a comprehensive data set of temperature and salinity observations for the second half of the twentieth century. Results from a regional Ocean General Circulation Model (OGCM) are used to assess the reliability of the averaging and the temporal interpolation of the inhomogeneous distributed observation data. The annual cycle explains only a minor part of the monthly variability for most of the region. The analysis on interannual to decadal timescales confined to the Norwegian Sea displays a clear rising trend starting at the end of the 1960s with particularly strong changes along the Barents Sea opening (6 to 7 cm). Moreover, a general freshening is found for the entire Norwegian Sea. In addition, a north-south dipole of the thermal component of the steric height variability is identified. This dipole elevates the general rising trend along the Barents Sea opening and reduces it in the southern Norwegian Sea. The bulk of the interannual variability in steric height is governed by variations in the local meridional wind stress that determine the relative distribution of Atlantic and Arctic waters in the Norwegian Sea. In addition, reduced heat loss to the atmosphere strongly correlates with the North Atlantic Oscillation winter index. This, in turn, may in particular explain the large steric height increase found at the Barents Sea opening.

  9. Sea Ice

    NASA Technical Reports Server (NTRS)

    Parkinson, Claire L.; Cavalieri, Donald J.

    2005-01-01

    Sea ice covers vast areas of the polar oceans, with ice extent in the Northern Hemisphere ranging from approximately 7 x 10(exp 6) sq km in September to approximately 15 x 10(exp 6) sq km in March and ice extent in the Southern Hemisphere ranging from approximately 3 x 10(exp 6) sq km in February to approximately 18 x 10(exp 6) sq km in September. These ice covers have major impacts on the atmosphere, oceans, and ecosystems of the polar regions, and so as changes occur in them there are potential widespread consequences. Satellite data reveal considerable interannual variability in both polar sea ice covers, and many studies suggest possible connections between the ice and various oscillations within the climate system, such as the Arctic Oscillation, North Atlantic Oscillation, and Antarctic Oscillation, or Southern Annular Mode. Nonetheless, statistically significant long-term trends are also apparent, including overall trends of decreased ice coverage in the Arctic and increased ice coverage in the Antarctic from late 1978 through the end of 2003, with the Antarctic ice increases following marked decreases in the Antarctic ice during the 1970s. For a detailed picture of the seasonally varying ice cover at the start of the 21st century, this chapter includes ice concentration maps for each month of 2001 for both the Arctic and the Antarctic, as well as an overview of what the satellite record has revealed about the two polar ice covers from the 1970s through 2003.

  10. Climate variability and long-term expansion of peat lands in Arctic Norway during the late Pliocene (ODP Site 642, Norwegian Sea)

    NASA Astrophysics Data System (ADS)

    Panitz, S.; Salzmann, U.; Risebrobakken, B.; De Schepper, S.; Pound, M. J.

    2015-12-01

    Little is known about the terrestrial response of high latitude Scandinavian vegetation to the warmer-than-present climate of the Late Pliocene (Piacenzian, 3.60-2.58 Ma). In order to assess Piacenzian terrestrial climate variability we present the first high resolution reconstruction of vegetation and climate change in northern Norway between 3.6-3.14 Ma. The reconstructions are derived from pollen assemblages in the marine sediments of ODP Hole 642B, Norwegian Sea (67° N). The palynological assemblages provide a unique record of latitudinal and altitudinal shifting of the forest boundaries, with vegetation alternating between cool temperate forest during warmer-than-present intervals, and boreal forest similar to today during cooler intervals. The northern boundary of the nemoral to boreonemoral forest zone was displaced at least 4-8° further north and warmest month temperatures were 6-14.5 °C higher than present during warm phases. Warm climatic conditions persisted during the earliest Piacenzian (ca. 3.6-3.47 Ma) with diverse cool temperate nemoral to boreonemoral forests growing in the lowlands of the Scandinavian mountains. A distinct cooling event at ca. 3.47 Ma resulted in a southward shift of vegetation boundaries, leading to the predominance of boreal forest and the development of open, low alpine environments. The cooling culminated around 3.3 Ma, coinciding with Marine Oxygen Isotope Stage (MIS) M2. Warmer climate conditions returned after ca. 3.29 Ma with higher climate variability indicated by the repeated expansion of forests and peat lands during warmer and cooler periods, respectively. Climate progressively cooled after 3.18 Ma, resembling climatic conditions during MIS M2. A high variability of Norwegian vegetation and climate changes during the Piacenzian is superimposed on a long-term cooling trend. This cooling was accompanied by an expansion of Sphagnum peat lands that potentially contributed to the decline in atmospheric CO2-concentrations at the end of the Piacenzian warm period and facilitated ice growth through positive vegetation-snow albedo feedbacks. Correlations with other Northern Hemisphere vegetation records suggest hemisphere-wide effects of climate cooling.

  11. Climate variability and long-term expansion of peatlands in Arctic Norway during the late Pliocene (ODP Site 642, Norwegian Sea)

    NASA Astrophysics Data System (ADS)

    Panitz, Sina; Salzmann, Ulrich; Risebrobakken, Bjørg; De Schepper, Stijn; Pound, Matthew J.

    2016-04-01

    Little is known about the terrestrial response of high-latitude Scandinavian vegetation to the warmer-than-present climate of the late Pliocene (Piacenzian, 3.60-2.58 Ma). In order to assess Piacenzian terrestrial climate variability, we present the first high-resolution reconstruction of vegetation and climate change in northern Norway between 3.6 and 3.14 Ma. The reconstructions are derived from pollen assemblages in the marine sediments of ODP Hole 642B, Norwegian Sea (67° N). The palynological assemblages provide a unique record of latitudinal and altitudinal shifting of the forest boundaries, with vegetation alternating between cool temperate forest during warmer-than-present intervals and boreal forest similar to today during cooler intervals. The northern boundary of the nemoral to boreonemoral forest zone was displaced at least 4-8° further north, and warmest-month temperatures were 6-14.5 °C higher than at present during warm phases. Warm climatic conditions persisted during the earliest Piacenzian (ca. 3.6-3.47 Ma) with diverse cool temperate nemoral to boreonemoral forests growing in the lowlands of the Scandinavian mountains. A distinct cooling event at ca. 3.47 Ma resulted in a southward shift of vegetation zones, leading to the predominance of boreal forest and the development of open, low alpine environments. The cooling culminated around 3.3 Ma, coinciding with Marine Isotope Stage (MIS) M2. Warmer climate conditions returned after ca. 3.29 Ma, with higher climate variability indicated by the repeated expansion of forests and peatlands during warmer and cooler periods, respectively. Climate progressively cooled after 3.18 Ma, resembling climatic conditions during MIS M2. A high variability of Norwegian vegetation and climate changes during the Piacenzian is superimposed on a long-term cooling trend. This cooling was accompanied by an expansion of Sphagnum peatlands that potentially contributed to the decline in atmospheric CO2 concentrations at the end of the Piacenzian warm period and facilitated ice growth through positive vegetation-snow albedo feedbacks. Correlations with other Northern Hemisphere vegetation records suggest hemisphere-wide effects of climate cooling.

  12. Mammals of the Sea.

    ERIC Educational Resources Information Center

    Naturescope, 1986

    1986-01-01

    Presents information on sea mammals, including definitions and characteristics of cetaceans, pinnipeds, and sirenians. Contains descriptions of the teaching activities "Whale Music,""Draw A Whale to Scale,""Adopt a Sea Mammal," and "Sea Mammal Sleuths." (TW)

  13. Studying Sea Otters

    Sea otter researcher Michelle Staedler, of the Monterey Bay Aquarium, records sea otter behavior in her logbook as part of a study with the USGS and the University of California at Santa Cruz on sea otter behavior. ...

  14. Tracking Sea Otters

    USGS sea otter researcher Tim Tinker drives the boat on an expedition to track and observe sea otters in Monterey Bay, California. USGS scientists study sea otters in efforts to help the threatened species continue to recover from near extinction....

  15. Lithospheric flexure across an extremely stretched and detached transform margin: Example from the East Greenland Ridge and Greenland FZ in the Norwegian-Greenland Sea.

    NASA Astrophysics Data System (ADS)

    Døssing, A.; Watts, A. B.

    2009-04-01

    The 250 km long East Greenland Ridge (EGR) is located along the Greenland Fracture Zone (GFZ), which is part of a first-order plate tectonic feature in the Norwegian-Greenland Sea that formed when Eocene seafloor spreading was translated along the De Geer megashear region between Greenland and Svalbard to the Arctic Ocean. The EGR rises abruptly about 250 km west from the Mohns-Knipovich Ridge axis in Chron 13 (33.3 Ma) crust and continues to Chron 24 (54.4 Ma) crust. Results of recently acquired wide-angle and MCS seismic data have shown that the EGR and an adjacent faulted basin province to the north of the ridge represent a continental sliver detached from the incipient NE Greenland and SW Barents Sea margins. Crustal thicknesses were found to be around 10 km (Døssing et al., 2008). The EGR-GFZ tectonic setting can therefore be rendered as an extremely stretched transform margin. A strong asymmetry is observed across the GFZ going from south to north with (i) a long wave-length downwards deflection of the oceanic crust, (ii) a steep southern flank of the EGR reaching more than 4 km above the predicted lithospheric thermal contraction level, and (iii) a gentle northern flank of the ridge dipping towards the faulted basin province. Hence, the ridge resembles the characteristics of other anomalously shallow, FZ parallel, transverse ridges. We propose a model in which flexural response of the lithosphere to normal faulting is responsible for the formation of the ridge. Interpretations of three, ~250 km long, seismic profiles normal to the GFZ are used to model the across-strike basement geometry. The results indicate that the observed lithospheric flexure was formed due to ~20 km extension normal to the GFZ along low-angle faults. Ref: Døssing, A., T. Dahl-Jensen, H. Thybo, R. Mjelde, and Y. Nishimura (2008), East Greenland Ridge in the North Atlantic Ocean: An integrated geophysical study of a continental sliver in a boundary transform fault setting, J. Geophys. Res., 113, B10107, doi: 10.1029/2007 JB005536.

  16. A Marine Controlled-Source Electromagnetic Study for the Characterization of Methane Hydrate and Free Gas Reservoirs at the Nyegga CNE03 Pockmark, Norwegian Sea

    NASA Astrophysics Data System (ADS)

    Attias, E.; Weitemeyer, K.; Sinha, M. C.; Minshull, T. A.; Jegen, M. D.; Berndt, C.

    2014-12-01

    In recent years, gas hydrate deposits have attracted growing interest from both academic and industry research, due to their potential as an unconventional energy resource, role in climate change and concern as a geohazard to various marine infrastructures. Methane hydrates are known to accommodate widespread regions of sea sediments at depths ranging from 130 to 2,000 m along offshore continental margins, normally located close to the seafloor and often presenting pockmarks that are underlain by chimney-like structures. The Nyegga region is situated along the west Norwegian continental slope and characterized by an extensive pockmark field. The Nyegga pockmarks are manifested by bathymetric troughs, seep-associated organisms, and rich methane-derived authigenic carbonate rocks. A controlled-source electromagnetic (CSEM) survey was performed along Nyegga CNE03 Pockmark, where high-resolution 3D seismic data was previously collected and analyzed. The aim of this CSEM study is to characterize the hydrate and free gas distribution along the CNE03 pockmark region. 2D CSEM inversions and pseudosections were computed using the data acquired by ocean bottom electrical field receivers (OBE) and the 3-axis towed receiver (Vulcan), respectively. Initial results from both data sets, confirm the existence of a subtle though distinctive resistivity anomaly structure at the CNE03 pockmark, suggesting a shallow anomaly at the chimney center, likely to result from the presence of gas hydrate. Furthermore, a deeper and latterly extensive resistivity anomaly emerged from the 2D inversions, most probably attributed to the existence of a free gas layer beneath the base of the gas hydrate stability zone (BGHSZ). This work will contribute to accurately estimate the amount of methane hydrate and free gas both at the pockmark level and over a larger regional scale, providing valuable information in light of the fact that there are more than 220 known gas hydrate deposits worldwide.

  17. Sea level annual cycle in sea level from tide gauges, altimetry and ocean models in the Polar Seas

    NASA Astrophysics Data System (ADS)

    Cheng, Y.; Andersen, O. B.

    2012-04-01

    Lack of adequate spatial and temporal sea level observations in the Polar Seas is one of the most challenging problems in the study of sea level variation and ocean circulation in the regions. The tide gauge data captures local sea level variability with long time span of data. Most of the stations are situated at the Norwegian and Russian border and hereby only observing the easternmost part of the Polar Seas.On the other hand, obtaining satellite data in high latitude regions is generally very problematic. In the Polar Seas, sea level has a significant annual cycle over the coastal regions. In this work, Simple Ocean Data Assimilation (SODA, 1950-2008) and DRAKKAR (ORCA025-G70, 1958-2004) ocean reanalysis are used in conjunction with tide gauge data and altimetric data to investigate the sea level annual cycle in the Polar Seas. The preliminary results show that the amplitude and phase of sea level annual cycle from different data sources are quite difference with each other for the period 1950-1979 and 1980-2008 over the selected regions. To compare with the results from gridded altimetric sea level anomaly maps (ERS-1, ERS-2 and Envisat), more investigation is performed from 1993 to 2009. Moreover, the annual sea level variation from CryoSat-2 data is used for the cross validation.

  18. Colorful Underwater Sea Creatures

    ERIC Educational Resources Information Center

    McCutcheon, Heather

    2011-01-01

    In this article, the author describes a project wherein students created colorful underwater sea creatures. This project began with a discussion about underwater sea creatures and how they live. The first step was making the multi-colored tissue paper that would become sea creatures and seaweed. Once students had the shapes of their sea creatures…

  19. Colorful Underwater Sea Creatures

    ERIC Educational Resources Information Center

    McCutcheon, Heather

    2011-01-01

    In this article, the author describes a project wherein students created colorful underwater sea creatures. This project began with a discussion about underwater sea creatures and how they live. The first step was making the multi-colored tissue paper that would become sea creatures and seaweed. Once students had the shapes of their sea creatures

  20. Beaufort Sea: information update

    SciTech Connect

    Becker, P.R.

    1988-04-01

    The report is based on a multi-disciplinary meeting held March 6-7, 1985, as part of preparations for the Beaufort Sea Sale 97. The chapters are based on presentations given: The causeway effect: Modification of nearshore thermal regime resulting from causeways; Summertime sea ice intrusions in the Chukchi Sea; The deepwater limit of ice gouging on the Beaufort Sea shelf; Distribution, abundance, migration, harvest, and stock identity of Belukha Whales in the Beaufort Sea; Ringed seals in the Beaufort Sea; Beaufort Sea socioeconomics; The Baffin Island Oil Spill, (BIOS) Project.

  1. Monitoring Arctic Sea ice using ERTS imagery. [Bering Sea, Beaufort Sea, Canadian Archipelago, and Greenland Sea

    NASA Technical Reports Server (NTRS)

    Barnes, J. C.; Bowley, C. J.

    1974-01-01

    Because of the effect of sea ice on the heat balance of the Arctic and because of the expanding economic interest in arctic oil and other minerals, extensive monitoring and further study of sea ice is required. The application of ERTS data for mapping ice is evaluated for several arctic areas, including the Bering Sea, the eastern Beaufort Sea, parts of the Canadian Archipelago, and the Greenland Sea. Interpretive techniques are discussed, and the scales and types of ice features that can be detected are described. For the Bering Sea, a sample of ERTS imagery is compared with visual ice reports and aerial photography from the NASA CV-990 aircraft.

  2. Aral Sea basin: a sea dies, a sea also rises.

    PubMed

    Glantz, Michael H

    2007-06-01

    The thesis of this article is quite different from many other theses of papers, books, and articles on the Aral Sea. It is meant to purposely highlight the reality of the situation in Central Asia: the Aral Sea that was once a thriving body of water is no more. That sea is dead. What does exist in its place are the Aral seas: there are in essence three bodies of water, one of which is being purposefully restored and its level is rising (the Little Aral), and two others which are still marginally connected, although they continue to decline in level (the Big Aral West and the Big Aral East). In 1960 the level of the sea was about 53 m above sea level. By 2006 the level had dropped by 23 m to 30 m above sea level. This was not a scenario generated by a computer model. It was a process of environmental degradation played out in real life in a matter of a few decades, primarily as a result of human activities. Despite wishes and words to the contrary, it will take a heroic global effort to save what remains of the Big Aral. It would also take a significant degree of sacrifice by people and governments in the region to restore the Big Aral to an acceptable level, given that the annual rate of flow reaching the Amudarya River delta is less than a 10th of what it was several decades ago. Conferring World Heritage status to the Aral Sea(s) could spark restoration efforts for the Big Aral. PMID:17626470

  3. 7 CFR 1437.310 - Sea grass and sea oats.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 10 2013-01-01 2013-01-01 false Sea grass and sea oats. 1437.310 Section 1437.310 Agriculture Regulations of the Department of Agriculture (Continued) COMMODITY CREDIT CORPORATION, DEPARTMENT... Determining Coverage Using Value § 1437.310 Sea grass and sea oats. (a) Sea grass and sea oats are value...

  4. 7 CFR 1437.310 - Sea grass and sea oats.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 10 2012-01-01 2012-01-01 false Sea grass and sea oats. 1437.310 Section 1437.310 Agriculture Regulations of the Department of Agriculture (Continued) COMMODITY CREDIT CORPORATION, DEPARTMENT... Determining Coverage Using Value § 1437.310 Sea grass and sea oats. (a) Sea grass and sea oats are value...

  5. 7 CFR 1437.310 - Sea grass and sea oats.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 10 2014-01-01 2014-01-01 false Sea grass and sea oats. 1437.310 Section 1437.310 Agriculture Regulations of the Department of Agriculture (Continued) COMMODITY CREDIT CORPORATION, DEPARTMENT... Determining Coverage Using Value § 1437.310 Sea grass and sea oats. (a) Sea grass and sea oats are value...

  6. 7 CFR 1437.310 - Sea grass and sea oats.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 10 2010-01-01 2010-01-01 false Sea grass and sea oats. 1437.310 Section 1437.310 Agriculture Regulations of the Department of Agriculture (Continued) COMMODITY CREDIT CORPORATION, DEPARTMENT... Determining Coverage Using Value § 1437.310 Sea grass and sea oats. (a) Sea grass and sea oats are value...

  7. 7 CFR 1437.310 - Sea grass and sea oats.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 10 2011-01-01 2011-01-01 false Sea grass and sea oats. 1437.310 Section 1437.310 Agriculture Regulations of the Department of Agriculture (Continued) COMMODITY CREDIT CORPORATION, DEPARTMENT... Determining Coverage Using Value § 1437.310 Sea grass and sea oats. (a) Sea grass and sea oats are value...

  8. Dispersal of the radionuclide caesium-137 ((137)Cs) from point sources in the Barents and Norwegian Seas and its potential contamination of the Arctic marine food chain: coupling numerical ocean models with geographical fish distribution data.

    PubMed

    Heldal, Hilde Elise; Vikebø, Frode; Johansen, Geir Odd

    2013-09-01

    Dispersal of (137)Cs from the nuclear submarine wrecks Komsomolets and K-159, which are resting on the seabed in the Norwegian and Barents Seas, respectively, is simulated using realistic rates and hypothetical scenarios. Furthermore, spatiotemporal (137)Cs concentrations in Northeast Arctic cod and capelin are estimated based on survey data. The results indicate that neither continuous leakages nor pulse discharges will cause concentrations of (137)Cs in cod muscle or whole body capelin exceeding the intervention level of 600 Bq/kg fw. Continuous leakages from Komsomolets and K-159 and pulse discharges from Komsomolets induced negligible activity concentrations in cod and capelin. A pulse discharge of 100% of the (137)Cs-inventory of K-159 will, however, result in concentrations in muscle of cod of above 100 times the present levels in the eastern Barents Sea. Within three years after the release, (137)Cs levels above 20 Bq/kg fw in cod are no longer occurring in the Barents Sea. PMID:23771062

  9. Sea ice transports in the Weddell Sea

    NASA Astrophysics Data System (ADS)

    Harms, Sabine; Fahrbach, Eberhard; Strass, Volker H.

    2001-05-01

    Time series of sea ice draft in the Weddell Sea are evaluated together with hydrographic observations, satellite passive microwave data, and ice drift for estimation of the freshwater fluxes into and out of the Weddell Sea. Ice draft is measured with moored upward looking sonars since 1990 along two transects across the Weddell Gyre. One transect, extending from the tip of the Antarctic Peninsula to Kapp Norvegia, was sampled between 1990 and 1994 and covers the flow into and out of the southern Weddell Sea. The other transect, sampled since 1996 and extending from the Antarctic continent northward along the Greenwich meridian, covers the exchange of water masses between the eastern and the western Weddell Sea. In order to relate results obtained during the different time periods, empirical relationships are established between the length of the sea ice season, derived from the satellite passive microwave data and defined as the number of days per year with the sea ice concentration exceeding 15%, and (1) the annual mean ice draft and (2) the annual mean ice volume transport. By using these empirical relationships, estimates of annual mean ice drafts and ice volume transports are derived at all mooring sites for the period February 1979 through February 1999. Wind and current force a westward ice transport in the coastal areas of the eastern Weddell Sea and a northward ice transport in the west. During the 2-year period 1991/1992 the mean ice volume export from the Weddell Sea is (50 ± 19) × 103 m3 s-1. This freshwater export is representative for a longer-term (20-year) mean and exceeds the average amount of freshwater gained by precipitation and ice shelf melt by about 19×103 m3 s-1, yielding an upper bound for the formation rate of newly ventilated bottom water in the Weddell Sea of 2.6 Sv.

  10. Deep sea waste disposal

    SciTech Connect

    Kester, D.R.; Burt, W.V.; Capuzzo, J.M.; Park, P.K.; Ketchum, B.W.; Duedall, I.W.

    1985-01-01

    The book presents papers on the marine disposal of wastes. Topics considered include incineration at sea, the modelling and biological effects of industrial wastes, microbial studies of ocean dumping, deep-sea mining wastes, the chemical analysis of ferromanganese nodules, and economic aspects of deep-sea disposal.

  11. All That Unplowed Sea

    ERIC Educational Resources Information Center

    MOSAIC, 1975

    1975-01-01

    Hunting and gathering at sea may fast be approaching their productive limits. Aquaculture - farming at sea - linked to conservation represents the sea's promise. If the system works, it might prove to be the key to supplying large amounts of food and fresh water at no cost in nonrenewable energy resources. (BT)

  12. Tracking Sea Otters

    Sea otter researchers Michelle Staedler, Monterey Bay Aquarium, and Tim Tinker, USGS, work together to locate sea otters in their study project. USGS scientists and their partners study sea otters in efforts to help the threatened species continue to recover from near extinction....

  13. Recent glacial events in the Norwegian North Sea - implications towards a better understanding of charging/leakage of oil fields and its impact oil exploration

    NASA Astrophysics Data System (ADS)

    Stoddart, Daniel

    2014-05-01

    Recent drilling and appraisal on the Southern Utsira High, Norwegian North Sea, has proved several large oil/gas discoveries, including the giant Johan Sverdrup, Edvard Grieg, Draupne, Ragnarrock and Apollo oil fields, making this a prolific petroleum area. The Southern Utsira High contains a variety of hydrocarbon density fluids found at several stratigraphic levels illustrating the compartmentalized nature of accumulations and charge history. The Southern Utsira High has been in a position to receive an oil/gas charge for a considerable period of time, with the basin towards the west most likely generating petroleum from early Eocene (50M Mabp) to its maximum present day burial depth. However, reservoir temperatures on the Southern Utsira High are just above the threshold for biodegradation (80°C). The Southern Utsira High oils are non-biodegraded suggesting that the majority of the oil charged relatively late - ca.3 million years ago to present day. The effects of the glaciation on the filling history of the Southern Utsira High are currently being assessed. It is clear that several erosional surfaces in the Pliocene can be identified, as well as glacial channels and moraine deposits, indicating that significant deposition and erosion occurred in the last five million years. Importantly, the effects of glacial rebound mean that the Southern Utsira High more than likely underwent tilting and possible leakage, not just once, but several times in the last 1 million years. The effects of tilting/leakage of geological areas on oil migration have been recognized by several authors. However, the detailed integration of geological mapping and geochemical evidence has not previously been published. The implications of a detailed assessment of tilting of a ''high' through time are; 1) opening up areas where oil migration is thought to be high risk or impossible; 2) identify possible paleo-oil columns aiding the de-risking of discovery appraisal strategies. The evidence of tilting/leakage of oil accumulations through time can be recognized in several oil fields on the Utsira High. The giant Johan Sverdrup discovery oil columns contain paleo-OWC, residual oil zones/paleo-oil columns, and oil shows considerably deeper than the current OWC or residual oil columns. Lundin has performed detailed mapping of the seabed and water column in the Alvheim/Utsira High areas in order to identify areas of gas leakage and its geological manifestations on the seabed and ultimately resulting in the collection of high quality samples. Results shows that gas leakage is prominent over the Alvheim and Utsira High areas and the implications of this to oil exploration will be discussed. In summary, Lundin's approach to oil migration is to better understand the fluid/gas movement throughout the whole basin through time. The talk will focus on the role of glaciations on the timing of charge from the South Viking Graben, fill-spill directions on the Southern Utsira High, the effects of late tilting/leakage on the charge/re-distribution of oil, and seabed / water column characterization and sampling. All placed in the context of oil exploration.

  14. Cenozoic stratigraphic evolution, North Sea and Labrador Sea

    SciTech Connect

    Gradstein, F.M.; Grant, A.C.; Mudford, B.S. ); Berggren, W.A. ); Kaminski, M.A. ); D'Lorio, M.A. ); Cloetingh, S. ); Griffiths, C.M. )

    1990-05-01

    The authors are studying Cenozoic correlation patterns, burial trends, and subsidence history of the Central North Sea, Labrador, and Orphan basins. The authors objectives are (1) to detail intraregional mid-high latitude biozonations using noise filtering and probabilistic zonation techniques; (2) to detail paleobathymetric trends from basin margins to centers; (3) to apply this knowledge to model basin evolution, in the perspective of the evolving North Atlantic Ocean; (4) to evaluate causes for the occurrence of major hiatuses and rapid changes of subsidence; and (5) to relate rapid changes in sedimentation in the last few millions of years to model observed undercompaction trends. Cenozoic microfossil assemblages in these basins are similar, related to similarities in sedimentary and paleoeceanographic conditions. In more basinal wells, flysch-type agglutinated foraminiferal assemblages occur, also known from Carpathians, Trinidad, and Moroccan foredeeps. Over 90% of agglutinated taxa are common between these basins, although local stratigraphic ranges vary sufficiently to rely on the concept of average ranges, rather than total ones for correlations. Cenozoic stratigraphic resolution in the North Sea and Labrador basins generally is in 3-5-Ma units. and paleobathymetric zonations define a minimum of five niches, from inner shelf to middle slope regimes. Significant hiatuses occurred in the late Eocene through the Miocene, particularly in northern Labrador and northern North Sea. Subsidence in the Labrador/Grand Banks passive margin half grabens was strongly influenced by Labrador Sea opening between anomalies 34 (Campanian) and 13 (early Oligocene), when subsidence exceeded sedimentation and bathyal conditions prevailed along the margin. Thermally induced subsidence in the central North Sea grabens was considerable in the late Paleocene, when the Norwegian Sea started to open.

  15. Regional sea level variability in the Bohai Sea, Yellow Sea, and East China Sea

    NASA Astrophysics Data System (ADS)

    Cheng, Yongcun; Plag, Hans-Peter; Hamlington, Benjamin D.; Xu, Qing; He, Yijun

    2015-12-01

    The regional sea level variability in the Bohai Sea (BS), Yellow Sea (YS) and East China Sea (ECS) is investigated based on tide gauge, satellite altimeter data and an independent oceanic general circulation model for the Earth Simulator (OFES) model outputs. It is found that atmospheric forcing significantly affects local sea level variability in the BS and YS and local sea level variability at the Southern ECS is highly correlated with along-shore currents. Particularly, the annual sea level fluctuations potentially change inundation risk and the frequency and magnitude of flooding in regions with high annual sea level. Hence, the cyclostationary empirical orthogonal function (CSEOF) analysis is carried out to investigate the variations of annual sea level cycle amplitude. Similar spatial distribution characteristics of annual sea level amplitude fluctuations are presented from satellite altimeter data and model outputs. The variability of annual sea level amplitude estimated from the satellite altimeter data agrees well with that from the tide gauge data, and positively (negatively) correlates with Southern Oscillation Index (Pacific Decadal Oscillation). The OFES model, however, underestimates the fluctuation of the annual cycle. After removing the annual signal, the low-passed (i.e., 13-month running mean) tide gauge data shows high correlations with SOI and PDO on time scales over 8 years in the BS and ECS.

  16. Dust Storm, Aral Sea

    NASA Technical Reports Server (NTRS)

    2002-01-01

    The Aral Sea has shrunk to less than half its size since 1985. The Aral Sea receives little water (sometimes no water) from the two major rivers that empty into it-the Syr Darya and Amu Darya. Instead, the river water is diverted to support irrigation for the region's extensive cotton fields. Recently, water scarcity has increased due to a prolonged drought in Central Asia. As the Aral Sea recedes, its former sea bed is exposed. The Aral's sea bed is composed of fine sediments-including fertilizers and other agricultural chemicals-that are easily picked up by the region's strong winds, creating thick dust storms. The International Space Station crew observed and recorded a large dust storm blowing eastward from the Aral Sea in late June 2001. This image illustrates the strong coupling between human activities (water diversions and irrigation), and rapidly changing land, sea and atmospheric processes-the winds blow across the

  17. North Sea difficult but prime area for applications

    SciTech Connect

    Skattum, K.S. )

    1990-04-02

    The Norwegian North Sea sector has been considered a very expensive area for subsea developments compared to the Gulf of Mexico and Brazil, where, the cost of a completed subsea well is several times less. An analysis of these large differences shows how the costs for North Sea projects can be reduced.

  18. The Nordic seas, main oceanographic features

    NASA Astrophysics Data System (ADS)

    Blindheim, Johan; Østerhus, Svein

    This article presents a review of the main oceanographic features of the Nordic Seas (the Greenland, Iceland, and Norwegian Seas). It includes a short description of previous research, the bathymetry of the area, its general circulation, and the exchanges with the North Atlantic and Arctic Oceans. Water mass structure and temporal variations are discussed separately for the various basins. The most prominent variations are a cooling and freshening in the upper layers since the 1960s, particularly in the southwestern Norwegian Sea, and a rise in temperature and salinity in the deeper layers, particularly in the Greenland Sea. Some relations of these variations to ocean—atmosphere interactions are described, and the deep-water warming is ascribed to an increased influence of deep water from the Arctic Ocean and a reduced formation of deep water in the Greenland Sea. Renewal of the deep water in the Greenland Sea occurred in the late 1960s, and atmospheric observations suggest that this may have been the only renewal event in the 20th century.

  19. East Siberian Sea, Russia

    NASA Technical Reports Server (NTRS)

    2002-01-01

    The winter sea ice in the east Siberian Sea is looking a bit like a cracked windshield in these true-color Moderate Resolution Imaging Spectroradiometer (MODIS) images from June 16 and 23, 2002. North of the thawing tundra, the sea ice takes on its cracked, bright blue appearance as it thins, which allows the reflection of the water to show through. Numerous still-frozen lakes dot the tundra. Credit: Jacques Descloitres, MODIS Land Rapid Response Team, NASA/GSFC

  20. Pelagic sea snakes dehydrate at sea.

    PubMed

    Lillywhite, Harvey B; Sheehy, Coleman M; Brischoux, François; Grech, Alana

    2014-05-01

    Secondarily marine vertebrates are thought to live independently of fresh water. Here, we demonstrate a paradigm shift for the widely distributed pelagic sea snake, Hydrophis (Pelamis) platurus, which dehydrates at sea and spends a significant part of its life in a dehydrated state corresponding to seasonal drought. Snakes that are captured following prolonged periods without rainfall have lower body water content, lower body condition and increased tendencies to drink fresh water than do snakes that are captured following seasonal periods of high rainfall. These animals do not drink seawater and must rehydrate by drinking from a freshwater lens that forms on the ocean surface during heavy precipitation. The new data based on field studies indicate unequivocally that this marine vertebrate dehydrates at sea where individuals may live in a dehydrated state for possibly six to seven months at a time. This information provides new insights for understanding water requirements of sea snakes, reasons for recent declines and extinctions of sea snakes and more accurate prediction for how changing patterns of precipitation might affect these and other secondarily marine vertebrates living in tropical oceans. PMID:24648228

  1. Pelagic sea snakes dehydrate at sea

    PubMed Central

    Lillywhite, Harvey B.; Sheehy, Coleman M.; Brischoux, François; Grech, Alana

    2014-01-01

    Secondarily marine vertebrates are thought to live independently of fresh water. Here, we demonstrate a paradigm shift for the widely distributed pelagic sea snake, Hydrophis (Pelamis) platurus, which dehydrates at sea and spends a significant part of its life in a dehydrated state corresponding to seasonal drought. Snakes that are captured following prolonged periods without rainfall have lower body water content, lower body condition and increased tendencies to drink fresh water than do snakes that are captured following seasonal periods of high rainfall. These animals do not drink seawater and must rehydrate by drinking from a freshwater lens that forms on the ocean surface during heavy precipitation. The new data based on field studies indicate unequivocally that this marine vertebrate dehydrates at sea where individuals may live in a dehydrated state for possibly six to seven months at a time. This information provides new insights for understanding water requirements of sea snakes, reasons for recent declines and extinctions of sea snakes and more accurate prediction for how changing patterns of precipitation might affect these and other secondarily marine vertebrates living in tropical oceans. PMID:24648228

  2. Hawksbill Sea Turtle (Eretmochelys imbricata)

    Hawksbill Sea Turtles (Eretmochelys imbricata), such as the one hiding here under a boulder, and Green Sea Turtles (Chelonia mydas) are occasionally seen in Hurricane Hole. Hawksbills feed mostly on sponges while Greens eat mostly sea grasses....

  3. [The characteristics of the population of the deep waters of the Norwegian Sea in the region of the loss of the Komsomolets nuclear-powered submarine].

    PubMed

    Vinogradov, M E; Shushkina, E A; Vereshchaka, A L; Nezlin, N P

    1995-01-01

    Specific features of vertical distribution and migration of planktonic organisms were studied for estimation of direct pathway of distribution of radionuclides in case they are released in the environment from the sunk nuclear submarine "Komsomolets" (73 degrees 42'N, 13 degrees 15'E, depth 1700 m). The materials were collected by 150-liter bathometers and planktonic nets in July 1994. In addition, planktonic animals were directly counted from deep-sea submarines "Mir". Distribution of the total biomass of plankton was considered and distribution in the water column from the surface to the depth 1700 m was quantitatively estimated for the following species: Calanus finmarchicus, C. hyperboreus, Metridia longa, Euchaeta spp., Sagitta elegans, Themisto abyssorum, and Hymenodora glacialis. The Norway sea hollow is filled by the local Arctic water and this facilitates penetration of many species during seasonal and other migrations down to the demersal layers, i.e., to depths, which are not specific for these organisms in basins with usual water stratification. Mass accumulations of Th. abyssorum have been found in the demersal layer, which is a main component of feeding of commercial plankton-eating fish as well as migrations of this crustacean across the water. PMID:8520439

  4. Red sea drillings.

    PubMed

    Ross, D A; Whitmarsh, R B; Ali, S A; Boudreaux, J E; Coleman, R; Fleisher, R L; Girdler, R; Manheim, F; Matter, A; Nigrini, C; Stoffers, P; Supko, P R

    1973-01-26

    Recent drilling in the Red Sea has shown that much of the basin is underlain by evaporites of a similar age to that of evaporites found in the Mediterranean Sea. These evaporites and their structural positions indicate that other brine areas are present-and, indeed, several others have been discovered. PMID:17843766

  5. Getting Your Sea Legs

    PubMed Central

    Stoffregen, Thomas A.; Chen, Fu-Chen; Varlet, Manuel; Alcantara, Cristina; Bardy, Benoît G.

    2013-01-01

    Sea travel mandates changes in the control of the body. The process by which we adapt bodily control to life at sea is known as getting one's sea legs. We conducted the first experimental study of bodily control as maritime novices adapted to motion of a ship at sea. We evaluated postural activity (stance width, stance angle, and the kinematics of body sway) before and during a sea voyage. In addition, we evaluated the role of the visible horizon in the control of body sway. Finally, we related data on postural activity to two subjective experiences that are associated with sea travel; seasickness, and mal de debarquement. Our results revealed rapid changes in postural activity among novices at sea. Before the beginning of the voyage, the temporal dynamics of body sway differed among participants as a function of their (subsequent) severity of seasickness. Body sway measured at sea differed among participants as a function of their (subsequent) experience of mal de debarquement. We discuss implications of these results for general theories of the perception and control of bodily orientation, for the etiology of motion sickness, and for general phenomena of perceptual-motor adaptation and learning. PMID:23840560

  6. Spotting Sea Otters

    USGS wildlife biologist Alisha Kage looks through a telescope to help her locate and identify tagged sea otters, then records the otter's location for a study aimed at learning more about the species. USGS scientists study sea otters in efforts to help the threatened species continue to recover from...

  7. Tracking Sea Otters

    USGS wildlife biologist Alisha Kage holds out a VHF receiver, hoping to hear the tell-tale beep that helps her locate sea otters that are part of study to monitor and learn more about the species. USGS scientists study sea otters in efforts to help the threatened species continue to recover from nea...

  8. Sea Anemone: Investigations.

    ERIC Educational Resources Information Center

    Hunt, John D.

    1982-01-01

    Several investigations can be undertaken with live sea anemones. A sea anemone's feeding response, fighting power, color, and symbiotic relationships to other invertebrates (such as a marine hermit crab) can be investigated in the high school classroom. Background information and laboratory procedures are provided. (Author/JN)

  9. Black Sea in Bloom

    NASA Technical Reports Server (NTRS)

    2002-01-01

    This true-color image shows bright, turquoise-colored swirls across the surface of the Black Sea, signifying the presence of a large phytoplankton bloom. Scientists have observed similar blooms recurring annually, roughly this same time of year. The Sea of Azov, which is the smaller body of water located just north of the Black Sea in this image, also shows a high level of biological activity currently ongoing. The brownish pixels in the Azov are probably sediments carried in from high waters upstream. This scene was acquired by the Sea-viewing Wide Field-of-view Sensor (SeaWiFS), flying aboard the OrbView-2 satellite, on May 4, 2002. According to the Black Sea Environment Programme's Marine Hydrophysical Institute, the Black Sea is 'one of the marine areas of the world most damaged by human activities.' The coastal zone around these Eastern European inland water bodies is densely populated-supporting a permanent population of roughly 16 million people and another 4 million tourists each year. Six countries border with the Black Sea, including Ukraine to the north, Russia and Georgia to the east, Turkey to the south, and Bulgaria and Romania to the west. Because it is isolated from the world's oceans, and because there is an extensive drainage network of rivers that empty into it, the Black Sea has a unique and delicate water balance which is very important for supporting its marine ecosystem. Of particular concern to scientists is the salinity, water level, and nutrient levels of the Black Sea's waters, all of which are, unfortunately, being impacted by human activities. Within the last three decades the combination of increased nutrient loads from human sources together with pollution and over-harvesting of fisheries has resulted in a sharp decline in water quality. Scientists from each of the Black Sea's bordering nations are currently working together to study the issues and formulate a joint, international strategy for saving this unique marine ecosystem. Working with a spirit of placing more emphasis on joint ownership of the Black Sea's resources, and less emphasis on blame, it is hoped that the cooperating countries can strike an effective balance between both enjoying and preserving the Black Sea. Image courtesy the SeaWiFS Project, NASA GSFC, and ORBIMAGE

  10. Global sea level rise

    SciTech Connect

    Douglas, B.C. )

    1991-04-15

    Published values for the long-term, global mean sea level rise determined from tide gauge records exhibit considerable scatter, from about 1 mm to 3 mm/yr. This disparity is not attributable to instrument error; long-term trends computed at adjacent sites often agree to within a few tenths of a millimeter per year. Instead, the differing estimates of global sea level rise appear to be in large part due to authors' using data from gauges located at convergent tectonic plate boundaries, where changes of land elevation give fictitious sea level trends. In addition, virtually all gauges undergo subsidence or uplift due to postglacial rebound (PGR) from the last deglaciation at a rate comparable to or greater than the secular rise of sea level. Modeling PGR by the ICE-3G model of Tushingham and Peltier (1991) and avoiding tide gauge records in areas of converging tectonic plates produces a highly consistent set of long sea level records. The value for mean sea level rise obtained from a global set of 21 such stations in nine oceanic regions with an average record length of 76 years during the period 1880-1980 is 1.8 mm/yr {plus minus} 0.1. This result provides confidence that carefully selected long tide gauge records measure the same underlying trend of sea level and that many old tide gauge records are of very high quality.

  11. Dead sea water intoxication.

    PubMed

    Levy-Khademi, Floris; Brooks, Rebecca; Maayan, Channa; Tenenbaum, Ariel; Wexler, Isaiah D

    2012-08-01

    Near drowning in the Dead Sea is associated with both respiratory manifestations and severe electrolyte abnormalities. It is often difficult to distinguish between the contributions of sea water aspiration or ingestion to clinical manifestations. We present a unique case of accidental ingestion of a large amount of Dead Sea water through a gastrostomy tube in which a patient with familial dysautonomia presented with severe electrolyte disturbances. Forced diuresis with large amounts of intravenous fluids resulted in clinical and biochemical improvement. Full recovery was achieved after 2 days of treatment. PMID:22863826

  12. Sea Perch Project

    NASA Technical Reports Server (NTRS)

    2010-01-01

    David Lalejini, an employee of the Naval Research Laboratory at NASA's John C. Stennis Space Center, helps a pair of teachers deploy a remotely-operated underwater Sea Perch robot during workshop activities Dec. 11. The Stennis Education Office teamed with Naval Research Laboratory counterparts to conduct a two-day workshop Dec. 10-11 for Louisiana and Mississippi teachers. During the no-cost workshop, teachers learned to build and operate Sea Perch robots. The teachers now can take the Sea Perch Program back to students.

  13. Sea level variation

    NASA Technical Reports Server (NTRS)

    Douglas, Bruce C.

    1992-01-01

    Published values for the long-term, global mean sea level rise determined from tide gauge records range from about one to three mm per year. The scatter of the estimates appears to arise largely from the use of data from gauges located at convergent tectonic plate boundaries where changes of land elevation give fictitious sea level trends, and the effects of large interdecadal and longer sea level variations on short (less than 50+ years) or sappy records. In addition, virtually all gauges undergo subsidence or uplift due to isostatic rebound from the last deglaciation at a rate comparable to or greater than the secular rise of sea level. Modeling rebound by the ICE-3G model of Tushingham and Peltier (1990) and avoiding tide gauge records in areas of converging tectonic plates produces a highly consistent set of long sea level records. A global set of 21 such stations in nine oceanic regions with an average record length of 76 years during the period 1880-1980 yields the global sea level rise value 1.8 mm/year +/- 0.1. Greenhouse warming scenarios commonly forecast an additional acceleration of global sea level in the next 5 or 6+ decades in the range 0.1-0.2 mm/yr2. Because of the large power at low frequencies in the sea level spectrum, very long tide gauge records (75 years minimum) have been examined for past apparent sea level acceleration. For the 80-year period 1905-1985, 23 essentially complete tide gauge records in 10 geographic groups are available for analysis. These yielded the apparent global acceleration -0.011 (+/- 0.012) mm/yr2. A larger, less uniform set of 37 records in the same 10 groups with 92 years average length covering the 141 years from 1850-1991 gave 0.001 (+/- 0.008) mm/yr2. Thus there is no evidence for an apparent acceleration in the past 100+ years that is significant either statistically, or in comparison to values associated with global warming. Unfortunately, the large interdecadal fluctuations of sea level severely affect estimates of global sea level acceleration for time spans of less than about 50 years. This means that tide gauges alone cannot serve as a reliable leading indicator of climate change in less than many decades. This time required can be significantly reduced if the interdecadal fluctuations of sea level can be understood in terms of their forcing mechanisms, and then removed from the tide gauge records.

  14. Science at Sea.

    ERIC Educational Resources Information Center

    Phillips, Mary Nied

    2001-01-01

    Describes a three-week inservice teacher education program that involves two sessions of preparatory classes ashore in nautical science and oceanography, and concludes with a nine-day sea voyage. (ASK)

  15. Sensing the sea bed

    NASA Astrophysics Data System (ADS)

    2009-07-01

    William Wilcock and a team of scientists and engineers drilled holes in the sea floor, and inadvertently provided a breeding ground for octopuses, in their attempt to understand deep-ocean hydrothermal venting.

  16. Mediterranean sea level variations.

    NASA Astrophysics Data System (ADS)

    Vigo, I.; Sánchez Reales, J. M.; García, D.; Chao, B. F.

    2009-04-01

    In this work we report an updated study of the sea level variations for the Mediterranean sea for the period from October 1992 to January 2008. The study addresses two mayor issues: (i)The analysis of the spatial and temporal variability of sea surface height (SSH) from radar altimetry measurements (from TOPEX/Poseidon (T/P) + Jason-1, etc.). We use EOF analysis to explain most of its interannual variation, and how the different basins interact. (ii) The analysis of dynamics and balance of water mass transport for the whole period. We estimate the steric SSH by combining the steric SSH estimated from temperature and salt profiles simulated by the ECCO model with time-variable gravity (TVG) data (from GRACE) for the Mediterranean Sea. The estimated steric SSH together with the SSH obtained from altimetry allow for a more realistic estimation of the water mass variations in the Mediterranean for the whole period.

  17. Dead Sea Scrolls

    NASA Technical Reports Server (NTRS)

    1994-01-01

    A consortium of researchers from Jet Propulsion Laboratory and three other organizations used charged coupled devices (CCDs) and other imaging enhancement technology to decipher previously unreadable portions of the Dead Sea Scrolls. The technique has potentially important implications for archeology.

  18. Sea ice ecosystems.

    PubMed

    Arrigo, Kevin R

    2014-01-01

    Polar sea ice is one of the largest ecosystems on Earth. The liquid brine fraction of the ice matrix is home to a diverse array of organisms, ranging from tiny archaea to larger fish and invertebrates. These organisms can tolerate high brine salinity and low temperature but do best when conditions are milder. Thriving ice algal communities, generally dominated by diatoms, live at the ice/water interface and in recently flooded surface and interior layers, especially during spring, when temperatures begin to rise. Although protists dominate the sea ice biomass, heterotrophic bacteria are also abundant. The sea ice ecosystem provides food for a host of animals, with crustaceans being the most conspicuous. Uneaten organic matter from the ice sinks through the water column and feeds benthic ecosystems. As sea ice extent declines, ice algae likely contribute a shrinking fraction of the total amount of organic matter produced in polar waters. PMID:24015900

  19. Record Sea Ice Minimum

    NASA Technical Reports Server (NTRS)

    2007-01-01

    Arctic sea ice reached a record low in September 2007, below the previous record set in 2005 and substantially below the long-term average. This image shows the Arctic as observed by the Advanced Microwave Scanning Radiometer for EOS (AMSR-E) aboard NASA's Aqua satellite on September 16, 2007. In this image, blue indicates open water, white indicates high sea ice concentration, and turquoise indicates loosely packed sea ice. The black circle at the North Pole results from an absence of data as the satellite does not make observations that far north. Three contour lines appear on this image. The red line is the 2007 minimum, as of September 15, about the same time the record low was reached, and it almost exactly fits the sea ice observed by AMSR-E. The green line indicates the 2005 minimum, the previous record low. The yellow line indicates the median minimum from 1979 to 2000.

  20. Sea Ice Ecosystems

    NASA Astrophysics Data System (ADS)

    Arrigo, Kevin R.

    2014-01-01

    Polar sea ice is one of the largest ecosystems on Earth. The liquid brine fraction of the ice matrix is home to a diverse array of organisms, ranging from tiny archaea to larger fish and invertebrates. These organisms can tolerate high brine salinity and low temperature but do best when conditions are milder. Thriving ice algal communities, generally dominated by diatoms, live at the ice/water interface and in recently flooded surface and interior layers, especially during spring, when temperatures begin to rise. Although protists dominate the sea ice biomass, heterotrophic bacteria are also abundant. The sea ice ecosystem provides food for a host of animals, with crustaceans being the most conspicuous. Uneaten organic matter from the ice sinks through the water column and feeds benthic ecosystems. As sea ice extent declines, ice algae likely contribute a shrinking fraction of the total amount of organic matter produced in polar waters.

  1. Sea level change

    SciTech Connect

    Meier, M.F.

    1996-12-31

    The IPCC (Intergovernmental Panel on Climate Change) 1995 Scientific Assessment, Chapter 7. Sea Level Change, presents a modest revision of the similar chapter in the 1990 Assessment. Principal conclusions on observed sea-level change and the principal terms in the sea-level equation (ocean thermal expansion, glaciers, ice sheets, and land hydrology), including our knowledge of the present-day (defined as the 20th Century) components of sea-level rise, and projections of these for the future, are presented here. Some of the interesting glaciological problems which are involved in these studies are discussed in more detail. The emphasis here is on trends over decades to a century, not on shorter variations nor on those of the geologic past. Unfortunately, some of the IPCC projections had not been agreed at the time of writing of this paper, and these projections will not be given here. 15 refs., 2 figs.

  2. Teacher at Sea.

    ERIC Educational Resources Information Center

    Beighley, Karl

    1998-01-01

    Outlines the experiences of a teacher in the National Oceanic and Atmospheric Administration's (NOAA) Teacher At Sea Program in which teachers are placed on NOAA vessels to work with professional scientists doing critical, real world research. (DDR)

  3. A Sea Experience.

    ERIC Educational Resources Information Center

    Glickstein, Neil

    1989-01-01

    Described is a teacher education program organized by the Sea Education Association in Woods Hole (Massachusetts). The experience, including activities and examples of studies conducted, is discussed. Contact information for future cruises is included. (CW)

  4. Black Sea Becomes Turquoise

    NASA Technical Reports Server (NTRS)

    2002-01-01

    This true-color image shows bright, turquoise-colored swirls across the surface of the Black Sea, signifying the presence of a large phytoplankton bloom. Scientists have observed similar blooms recurring annually, roughly this same time of year. The Sea of Azov, which is the smaller body of water located just north of the Black Sea in this image, also shows a high level of color variance. The brownish pixels in the Azov are probably due to sediments carried in from high waters and snowmelt from upstream. This scene was acquired by the Moderate Resolution Imaging Spectroradiometer, flying aboard NASA's Terra satellite, on May 14, 2002. According to the Black Sea Environment Programme's Marine Hydrophysical Institute, the Black Sea is ?one of the marine areas of the world most damaged by human activities.? The coastal zone around these Eastern European inland water bodies is densely populated'supporting a permanent population of roughly 16 million people and another 4 million tourists each year. Six countries border with the Black Sea, including Ukraine to the north, Russia and Georgia to the east, Turkey to the south, and Bulgaria and Romania to the west. Because it is isolated from the world's oceans, and because there is an extensive drainage network of rivers that empty into it, the Black Sea has a unique and delicate water balance which is very important for supporting its marine ecosystem. Of particular concern to scientists is the salinity, water level, and nutrient levels of the Black Sea's waters, all of which are, unfortunately, being impacted by human activities. Within the last three decades the combination of increased nutrient loads from human sources together with pollution and over-harvesting of fisheries has resulted in a sharp decline in water quality. Scientists from each of the Black Sea's bordering nations are currently working together to study the issues and formulate a joint, international strategy for saving this unique marine ecosystem. Working with a spirit of placing more emphasis on joint ownership of the Black Sea's resources, and less emphasis on blame, it is hoped that the cooperating countries can strike an effective balance between both enjoying and preserving the Black Sea.

  5. South China Sea.

    PubMed

    Morton, B; Blackmore, G

    2001-12-01

    The South China Sea is poorly understood in terms of its marine biota, ecology and the human impacts upon it. What is known is most often contained in reports and workshop and conference documents that are not available to the wider scientific community. The South China Sea has an area of some 3.3 million km2 and depths range from the shallowest coastal fringe to 5377 m in the Manila Trench. It is also studded with numerous islets, atolls and reefs many of which are just awash at low tide. It is largely confined within the Tropic of Cancer and, therefore, experiences a monsoonal climate being influenced by the Southwest Monsoon in summer and the Northeast Monsoon in winter. The South China Sea is a marginal sea and, therefore, largely surrounded by land. Countries that have a major influence on and claims to the sea include China, Malaysia, the Philippines and Vietnam, although Thailand, Indonesia and Taiwan have some too. The coastal fringes of the South China Sea are home to about 270 million people that have had some of the fastest developing and most vibrant economies on the globe. Consequently, anthropogenic impacts, such as over-exploitation of resources and pollution, are anticipated to be huge although, in reality, relatively little is known about them. The Indo-West Pacific biogeographic province, at the centre of which the South China Sea lies, is probably the world's most diverse shallow-water marine area. Of three major nearshore habitat types, i.e., coral reefs, mangroves and seagrasses, 45 mangrove species out of a global total of 51, most of the currently recognised 70 coral genera and 20 of 50 known seagrass species have been recorded from the South China Sea. The island groups of the South China Sea are all disputed and sovereignty is claimed over them by a number of countries. Conflicts have in recent decades arisen over them because of perceived national rights. It is perhaps because of this that so little research has been undertaken on the South China Sea. What data are available, however, and if Hong Kong is used, as it is herein, as an indicator of what the perturbations of other regional cities upon the South China Sea are like, then it is impacted grossly and an ecological disaster has probably already, but unknowingly, happened. PMID:11827109

  6. Sea bed mechanics

    SciTech Connect

    Sleath, J.F.A.

    1984-01-01

    This book provides a discussion on sea bed processes with engineering applications. It brings together the material currently available only in technical reports of research papers. It provides formulae and background references necessary for design calculation of problems such as sea bed or coastal erosion, and sub-marine pipeline stability. It also covers dissipation of wave energy, formation of ripples and dunes, and the transportation of sediments.

  7. Contemporary sea level rise.

    PubMed

    Cazenave, Anny; Llovel, William

    2010-01-01

    Measuring sea level change and understanding its causes has considerably improved in the recent years, essentially because new in situ and remote sensing observations have become available. Here we report on most recent results on contemporary sea level rise. We first present sea level observations from tide gauges over the twentieth century and from satellite altimetry since the early 1990s. We next discuss the most recent progress made in quantifying the processes causing sea level change on timescales ranging from years to decades, i.e., thermal expansion of the oceans, land ice mass loss, and land water-storage change. We show that for the 1993-2007 time span, the sum of climate-related contributions (2.85 +/- 0.35 mm year(-1)) is only slightly less than altimetry-based sea level rise (3.3 +/- 0.4 mm year(-1)): approximately 30% of the observed rate of rise is due to ocean thermal expansion and approximately 55% results from land ice melt. Recent acceleration in glacier melting and ice mass loss from the ice sheets increases the latter contribution up to 80% for the past five years. We also review the main causes of regional variability in sea level trends: The dominant contribution results from nonuniform changes in ocean thermal expansion. PMID:21141661

  8. Thermohaline circulation in the Arctic Mediterranean Seas

    NASA Astrophysics Data System (ADS)

    Aagaard, K.; Swift, J. H.; Carmack, E. C.

    1985-05-01

    The renewal of the deep North Atlantic by the various overflows of the Greenland-Scotland ridges is only one manifestation of the convective and mixing processes which occur in the various basins and shelf areas to the north: the Arctic Ocean and the Greenland, Iceland, and Norwegian seas, collectively called the Arctic Mediterranean. The traditional site of deep ventilation for these basins is the Greenland Sea, but a growing body of evidence also points to the Arctic Ocean as a major source of deep water. This deep water is relatively warm and saline, and it appears to be a mixture of dense, brine-enriched shelf water with intermediate strata in the Arctic Ocean. The deep water exits the Arctic Ocean along the Greenland slope to mix with the Greenland Sea deep water. Conversely, very cold low-salinity deep water from the Greenland Sea enters the Arctic Ocean west of Spitsbergen. Within the Arctic Ocean, the Lomonosov Ridge excludes the Greenland Sea deep water from the Canadian Basin, leaving the latter warm, saline, and rich in silica. In general, the entire deep-water sphere of the Arctic Mediterranean is constrained by the Greenland-Scotland ridges to circulate internally. Therefore it is certain of the intermediate waters formed in the Greenland and Iceland seas which ventilate the North Atlantic. These waters have a very short residence time in their formation areas and are therefore able to rapidly transmit surface-induced signals into the deep North Atlantic.

  9. Annual sea ice. An air-sea gas exchange moderator

    SciTech Connect

    Gosink, T.A.; Kelley, J.J.

    1982-01-01

    Arctic annual sea ice, particularly when it is relatively warm (> -15/sup 0/C) permits significant gas exchange between the sea and air throughout the entire year. Sea ice, particularly annual sea ice, differs from freshwater ice with respect to its permeability to gases. The presence of brine allows for significant air-sea-ice exchange of CO/sub 2/ throughout the winter, which may significantly affect the global carbon dioxide balance. Other trace gases are also noted to be enriched in sea ice, but less is known about their importance to air-sea-interactions at this time. Both physical and biological factors cause and modify evolution of gases from the surface of sea ice. Quantitative and qualitative descriptions of the nature and physical behavior of sea ice with respect to brine and gases are discussed.

  10. The White Sea, Russia

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Editor's Note: The caption below, published on May 10, 2001, is incorrect. According to Masha Vorontsova, director of the International Fund for Animal Welfare in Moscow, the situation with the seal pups in the White Sea is normal. There is no disaster and there never was. For more details, refer to the article entitled 'No Danger' on the New Scientist home page. The Earth Observatory regrets the earlier errant report. Original Caption According to the Russian Polar Research Institute for Fisheries and Oceanography, between 250,000 and 300,000 Greenland seal pups face death by starvation over the next two months due to a cruel trick by mother nature. The seals, most of them less than two months old, are trapped on ice sheets that remain locked in the White Sea, located near Archangel in Northern Russia. Typically, during the spring thaw the ice sheets break up and flow with the currents northward into the Barents Sea, the seals' spring feeding grounds. The seal pups hitch a ride on the ice floes, living on their own individual stores of fat until they arrive in the Barents Sea. Their mothers departed for the Barents Sea weeks ago. In a normal year, the seal pups' trip from the White Sea out to the Barents takes about six weeks and the seals have adapted to rely upon this mechanism of mother nature. During their yearly migration, the mother seals usually stay with their pups and feed them until their pelts turn from white to grey--a sign that the pups are mature enough to swim and feed themselves. Unfortunately, this year unusually strong northerly winds created a bottleneck of ice near the mouth of the white sea, thus blocking the flow of ice and trapping the pups. These true-color images of the White Sea were acquired by the Moderate-resolution Imaging Spectroradiometer (MODIS), flying aboard NASA's Terra spacecraft. This image, taken May 2, 2000 that there is usually much less ice in the White Sea this time of year as most of it is typically en route to the Barents Sea.

  11. The Dead Sea

    NASA Technical Reports Server (NTRS)

    2006-01-01

    The Dead Sea is the lowest point on Earth at 418 meters below sea level, and also one of the saltiest bodies of water on Earth with a salinity of about 300 parts-per-thousand (nine times greater than ocean salinity). It is located on the border between Jordan and Israel, and is fed by the Jordan River. The Dead Sea is located in the Dead Sea Rift, formed as a result of the Arabian tectonic plate moving northward away from the African Plate. The mineral content of the Dead Sea is significantly different from that of ocean water, consisting of approximately 53% magnesium chloride, 37% potassium chloride and 8% sodium chloride. In the early part of the 20th century, the Dead Sea began to attract interest from chemists who deduced that the Sea was a natural deposit of potash and bromine. From the Dead Sea brine, Israel and Jordan produce 3.8 million tons potash, 200,000 tons elemental bromine, 45,000 tons caustic soda, 25, 000 tons magnesium metal, and sodium chloride. Both countries use extensive salt evaporation pans that have essentially diked the entire southern end of the Dead Sea.

    With its 14 spectral bands from the visible to the thermal infrared wavelength region, and its high spatial resolution of 15 to 90 meters (about 50 to 300 feet), ASTER images Earth to map and monitor the changing surface of our planet.

    ASTER is one of five Earth-observing instruments launched December 18, 1999, on NASA's Terra satellite. The instrument was built by Japan's Ministry of Economy, Trade and Industry. A joint U.S./Japan science team is responsible for validation and calibration of the instrument and the data products.

    The broad spectral coverage and high spectral resolution of ASTER provides scientists in numerous disciplines with critical information for surface mapping, and monitoring of dynamic conditions and temporal change. Example applications are: monitoring glacial advances and retreats; monitoring potentially active volcanoes; identifying crop stress; determining cloud morphology and physical properties; wetlands evaluation; thermal pollution monitoring; coral reef degradation; surface temperature mapping of soils and geology; and measuring surface heat balance.

    The U.S. science team is located at NASA's Jet Propulsion Laboratory, Pasadena, Calif. The Terra mission is part of NASA's Science Mission Directorate.

    Size: 18.5 by 48.1 kilometers (11.5 by 29.8 miles) Location: 31.4 degrees North latitude, 35.4 degrees East longitude Orientation: North at top Image Data: ASTER bands 3, 2, and 1 Original Data Resolution: 15 meters (49.2 feet) Dates Acquired: May 3, 2005

  12. On large outflows of Arctic sea ice into the Barents Sea

    NASA Technical Reports Server (NTRS)

    Kwok, Ron; Maslowski, Wieslaw; Laxon, Seymour W.

    2005-01-01

    Winter outflows of Arctic sea ice into the Barents Sea are estimated using a 10-year record of satellite ice motion and thickness. The mean winter volume export through the Svalbard/Franz Josef Land passage is 40 km3, and ranges from -280 km3 to 340 km3. A large outflow in 2003 is preconditioned by an unusually high concentration of thick perennial ice over the Nansen Basin at the end of the 2002 summer. With a deep atmospheric low situated over the eastern Barents Sea in winter, the result is an increased export of Arctic ice. The Oct-Mar ice area flux, at 110 x 10 to the third power km3, is not only unusual in magnitude but also remarkable in that >70% of the area is multiyear ice; the ice volume flux at340 km3 is almost one-fifth of the ice flux through the Fram Strait. Another large outflow of Arctic sea ice through this passage, comparable to that in 2003, is found in 1996. This southward flux of sea ice represents one of two major sources of freshwater in the Barents Sea; the other is the eastward flux of water via the Norwegian Coastal Current. The possible consequences of variable freshwater input on the Barents Sea hydrography and its impact on transformation of Atlantic Water en route to the Arctic Ocean are examined with a 25-year coupled ice-ocean model.

  13. Caribbean Sea Level Network

    NASA Astrophysics Data System (ADS)

    von Hillebrandt-Andrade, C.; Crespo Jones, H.

    2012-12-01

    Over the past 500 years almost 100 tsunamis have been observed in the Caribbean and Western Atlantic, with at least 3510 people having lost their lives to this hazard since 1842. Furthermore, with the dramatic increase in population and infrastructure along the Caribbean coasts, today, millions of coastal residents, workers and visitors are vulnerable to tsunamis. The UNESCO IOC Intergovernmental Coordination Group for Tsunamis and other Coastal Hazards for the Caribbean and Adjacent Regions (CARIBE EWS) was established in 2005 to coordinate and advance the regional tsunami warning system. The CARIBE EWS focuses on four areas/working groups: (1) Monitoring and Warning, (2) Hazard and Risk Assessment, (3) Communication and (4) Education, Preparedness and Readiness. The sea level monitoring component is under Working Group 1. Although in the current system, it's the seismic data and information that generate the initial tsunami bulletins, it is the data from deep ocean buoys (DARTS) and the coastal sea level gauges that are critical for the actual detection and forecasting of tsunamis impact. Despite multiple efforts and investments in the installation of sea level stations in the region, in 2004 there were only a handful of sea level stations operational in the region (Puerto Rico, US Virgin Islands, Bermuda, Bahamas). Over the past 5 years there has been a steady increase in the number of stations operating in the Caribbean region. As of mid 2012 there were 7 DARTS and 37 coastal gauges with additional ones being installed or funded. In order to reach the goal of 100 operational coastal sea level stations in the Caribbean, the CARIBE EWS recognizes also the importance of maintaining the current stations. For this, a trained workforce in the region for the installation, operation and data analysis and quality control is considered to be critical. Since 2008, three training courses have been offered to the sea level station operators and data analysts. Other requirements and factors have been considered for the sustainability of the stations. The sea level stations have to potentially sustain very aggressive conditions of not only tsunamis, but on a more regular basis, hurricanes. Given the requirement that the data be available in near real time, for tsunami and other coastal hazard application, robust communication systems are also essential. For the local operator, the ability to be able to visualize the data is critical and tools like the IOC Sea level Monitoring Facility and the Tide Tool program are very useful. It has also been emphasized the need for these stations to serve multiple purposes. For climate and other research applications the data need to be archived, QC'd and analyzed. Increasing the user base for the sea level data has also been seen as an important goal to gain the local buy in; local weather and meteorological offices are considered as key stakeholders but for whom applications still need to be developed. The CARIBE EWS continues to look forward to working with other IOC partners including the Global Sea Level Observing System (GLOSS) and Sub-Commission for the Caribbean and Adjacent Regions (IOCARIBE)/GOOS, as well as with local, national and global sea level station operators and agencies for the development of a sustainable sea level network.

  14. Upper ocean heat content in the Nordic seas

    NASA Astrophysics Data System (ADS)

    di Iorio, Daniela; Sloan, Caitlin

    2009-04-01

    Seven years of temperature profiles are obtained from the Argo float project and are used to study the vertically integrated heat content for the Nordic seas which is broken up into the Norwegian Basin, Greenland Sea, Lofoten region, and Iceland Plateau. The World Ocean Atlas 2005 (WOA05) is used as the climatological baseline for temperature and hence heat content. Temporally and spatially averaged temperature profiles within the Norwegian and Iceland basins show good agreement between the Argo and WOA05 data sets. For the Greenland and Lofoten basins, the WOA05 data show cooler surface temperatures (by 1-2C) but still lie within 1 standard deviation of each other over the 7-year period. The Argo float data show circulation within each of the basins that is counterclockwise, and some of the floats eventually disperse toward the outer edges of the basins. Vertically integrated heat content from 0 to 1200 m shows similar characteristics as the WOA05 results including the timing and strength of the seasonal variability. The anomalous heat content for the Greenland and Norwegian sea basins is calculated in depth bins of 400 m. The Greenland Sea shows a warming trend over the 7 years of study, which corresponds to a temperature increase of (4.1 0.3) 10-2 C/yr. The Norwegian Sea basin shows interannual variability in heat content for the surface layer (0-400 m) that may be related to the North Atlantic Oscillation (NAO). During an NAO+ phase, the Norwegian Basin shows a warm phase, and during an NAO- phase, the Norwegian Basin is in a cold phase; the correlation is small (r = 0.32) but different from zero correlation only at the 90% level, implying that the variability in the AHC may be due to (1) local atmospheric forcing and hence changes in heat loss, (2) atmospheric pressure differences that are not resolved by the NAO index, and (3) exchange of heat with the basin boundaries.

  15. Understanding Sea Level Changes

    NASA Technical Reports Server (NTRS)

    Chao, Benjamin F.

    2004-01-01

    Today more than 100 million people worldwide live on coastlines within one meter of mean sea level; any short-term or long-term sea level change relative to vertical ground motion is of great societal and economic concern. As palm-environment and historical data have clearly indicated the existence and prevalence of such changes in the past, new scientific information regarding to the nature and causes and a prediction capability are of utmost importance for the future. The 10-20 cm global sea-level rise recorded over the last century has been broadly attributed to two effects: (1) the steric effect (thermal expansion and salinity-density compensation of sea water) following global climate; (2) mass-budget changes due to a number of competing geophysical and hydrological processes in the Earth-atmosphere-hydrosphere-cryosphere system, including water exchange from polar ice sheets and mountain glaciers to the ocean, atmospheric water vapor and land hydrological variations, and anthropogenic effects such as water impoundment in artificial reservoirs and extraction of groundwater, all superimposed on the vertical motions of solid Earth due to tectonics, rebound of the mantle from past and present deglaciation, and other local ground motions. As remote-sensing tools, a number of space geodetic measurements of sea surface topography (e.g., TOPEX/Poseidon, Jason), ice mass (e.g., ICESat), time-variable gravity (e.g. GRACE), and ground motions (SLR, VLBI, GPS, InSAR, Laser altimetry, etc.) become directly relevant. Understanding sea level changes "anywhere, anytime" in a well-defined terrestrial reference frame in terms of climate change and interactions among ice masses, oceans, and the solid Earth, and being able to predict them, emerge as one of the scientific challenges in the Solid Earth Science Working Group (SESWG, 2003) conclusions.

  16. Mechanisms of long-term mean sea level variability in the North Sea

    NASA Astrophysics Data System (ADS)

    Dangendorf, Sönke; Calafat, Francisco; Øie Nilsen, Jan Even; Richter, Kristin; Jensen, Jürgen

    2015-04-01

    We examine mean sea level (MSL) variations in the North Sea on timescales ranging from months to decades under the consideration of different forcing factors since the late 19th century. We use multiple linear regression models, which are validated for the second half of the 20th century against the output of a state-of-the-art tide+surge model (HAMSOM), to determine the barotropic response of the ocean to fluctuations in atmospheric forcing. We demonstrate that local atmospheric forcing mainly triggers MSL variability on timescales up to a few years, with the inverted barometric effect dominating the variability along the UK and Norwegian coastlines and wind (piling up the water along the coast) controlling the MSL variability in the south from Belgium up to Denmark. However, in addition to the large inter-annual sea level variability there is also a considerable fraction of decadal scale variability. We show that on decadal timescales MSL variability in the North Sea mainly reflects steric changes, which are mostly remotely forced. A spatial correlation analysis of altimetry observations and baroclinic ocean model outputs suggests evidence for a coherent signal extending from the Norwegian shelf down to the Canary Islands. This supports the theory of longshore wind forcing along the eastern boundary of the North Atlantic causing coastally trapped waves to propagate along the continental slope. With a combination of oceanographic and meteorological measurements we demonstrate that ~80% of the decadal sea level variability in the North Sea can be explained as response of the ocean to longshore wind forcing, including boundary wave propagation in the Northeast Atlantic. These findings have important implications for (i) detecting significant accelerations in North Sea MSL, (ii) the conceptual set up of regional ocean models in terms of resolution and boundary conditions, and (iii) the development of adequate and realistic regional climate change projections.

  17. Law of the Sea

    SciTech Connect

    Borgese, E.M.

    1983-03-01

    Seabed development will proceed even though the US declined to join 119 nations signing the Law of the Sea Treaty. The new law replaces laissez faire development with management of the seas. The US, Soviet Union, and 15 other countries, while withholding their signatures from the convention, did sign the Final Act of the Conference and can sign as full participants in the future if they choose. The new management approach considers global socio-economic and resource needs. It emphasizes international cooperation in the areas of economic development, disarmament, and in establishing rules and regulations for exploring the seabed. (DCK)

  18. Spectacled Eiders Wintering in Northern Bering Sea

    Large flock of Spectacled Eiders aggregated in a sea ice lead and on sea ice in the northern Bering Sea, south of St. Lawrence Island, Alaska.  Aerial photograph from a helicopter deployed from the USCG Cutter Polar Sea....

  19. A lithosphere-scale structural model of the Barents Sea and Kara Sea region

    NASA Astrophysics Data System (ADS)

    Klitzke, P.; Faleide, J. I.; Scheck-Wenderoth, M.; Sippel, J.

    2014-07-01

    The Barents Sea and Kara Sea region as part of the European Arctic shelf, is geologically situated between the Proterozoic East-European Craton in the south and early Cenozoic passive margins in the north and the west. Proven and inferred hydrocarbon resources encouraged numerous industrial and academic studies in the last decades which brought along a wide spectrum of geological and geophysical data. By evaluating all available interpreted seismic refraction and reflection data, geological maps and previously published 3-D-models, we were able to develop a new lithosphere-scale 3-D-structural model for the greater Barents Sea and Kara Sea region. The sedimentary part of the model resolves four major megasequence boundaries (earliest Eocene, mid-Cretaceous, mid-Jurassic and mid-Permian). Downwards, the 3-D-structural model is complemented by the top crystalline crust, the Moho and a newly calculated lithosphere-asthenosphere boundary (LAB). The thickness distribution of the main megasequences delineates five major subdomains differentiating the region (the northern Kara Sea, the southern Kara Sea, the eastern Barents Sea, the western Barents Sea and the oceanic domain comprising the Norwegian-Greenland Sea and the Eurasia Basin). The vertical resolution of five sedimentary megasequences allows comparing for the first time the subsidence history of these domains directly. Relating the sedimentary structures with the deeper crustal/lithospheric configuration sheds some light on possible causative basin forming mechanisms that we discuss. The newly calculated LAB deepens from the typically shallow oceanic domain in three major steps beneath the Barents and Kara shelves towards the West-Siberian Basin in the east. Thereby, we relate the shallow continental LAB and slow/hot mantle beneath the southwestern Barents Sea with the formation of deep Paleozoic/Mesozoic rift basins. Thinnest continental lithosphere is observed beneath Svalbard and the NW Barents Sea where no Mesozoic/early Cenozoic rifting has occurred but strongest Cenozoic uplift and volcanism since Miocene times. The East Barents Sea Basin is underlain by a LAB at moderate depths and a high-density anomaly in the lithospheric mantle which follows the basin geometry and a domain where the least amount of late Cenozoic uplift/erosion is observed. Strikingly, this high-density anomaly is not present beneath the adjacent southern Kara Sea. Both basins share a strong Mesozoic subsidence phase whereby the main subsidence phase is younger in the South Kara Sea Basin.

  20. Seafloor Control on Sea Ice

    NASA Technical Reports Server (NTRS)

    Nghiem, S. V.; Clemente-Colon, P.; Rigor, I. G.; Hall, D. K.; Neumann, G.

    2011-01-01

    The seafloor has a profound role in Arctic sea ice formation and seasonal evolution. Ocean bathymetry controls the distribution and mixing of warm and cold waters, which may originate from different sources, thereby dictating the pattern of sea ice on the ocean surface. Sea ice dynamics, forced by surface winds, are also guided by seafloor features in preferential directions. Here, satellite mapping of sea ice together with buoy measurements are used to reveal the bathymetric control on sea ice growth and dynamics. Bathymetric effects on sea ice formation are clearly observed in the conformation between sea ice patterns and bathymetric characteristics in the peripheral seas. Beyond local features, bathymetric control appears over extensive ice-prone regions across the Arctic Ocean. The large-scale conformation between bathymetry and patterns of different synoptic sea ice classes, including seasonal and perennial sea ice, is identified. An implication of the bathymetric influence is that the maximum extent of the total sea ice cover is relatively stable, as observed by scatterometer data in the decade of the 2000s, while the minimum ice extent has decreased drastically. Because of the geologic control, the sea ice cover can expand only as far as it reaches the seashore, the continental shelf break, or other pronounced bathymetric features in the peripheral seas. Since the seafloor does not change significantly for decades or centuries, sea ice patterns can be recurrent around certain bathymetric features, which, once identified, may help improve short-term forecast and seasonal outlook of the sea ice cover. Moreover, the seafloor can indirectly influence cloud cover by its control on sea ice distribution, which differentially modulates the latent heat flux through ice covered and open water areas.

  1. Solar Sea Power

    ERIC Educational Resources Information Center

    Zener, Clarence

    1976-01-01

    In their preoccupation with highly complex new energy systems, scientists and statesmen may be overlooking the possibilities of Ocean Thermal Energy Conversion (OTEC). That is the view of a Carnegie-Mellon University physicist who is in the forefront of solar sea power investigation. (Author/BT)

  2. Virtual sea border

    NASA Astrophysics Data System (ADS)

    Ferriere, D.; Rucinski, A.; Jankowski, T.

    2007-04-01

    Establishing a Virtual Sea Border by performing a real-time, satellite-accessible Internet-based bio-metric supported threat assessment of arriving foreign-flagged cargo ships, their management and ownership, their arrival terminal operator and owner, and rewarding proven legitimate operators with an economic incentive for their transparency will simultaneously improve port security and maritime transportation efficiencies.

  3. Classroom of the Sea.

    ERIC Educational Resources Information Center

    Hupper, Mary Laporta; Monte, Denise; Scheifele, Peter

    2000-01-01

    Introduces the Sea Program in which participant students were deaf and collaborated with a bioacoustician. Studies the underwater noise levels of the Gulf of Maine and the possible impacts on marine life. Explains implementing this project in the science curriculum. (YDS)

  4. Farming the Sea

    ERIC Educational Resources Information Center

    Morgan, William

    1971-01-01

    Florida has initiated a training program in an entirely new dimension--Sea Farming. Presented is a description of the vocational agriculture program designed to teach propagation, cultivation, harvesting, marketing, and conservation practices related to production of oysters, shrimp, scallops, crabs, and fin fishes. (Editor/GB)

  5. Alaska: Beaufort Sea

    Atmospheric Science Data Center

    2014-05-15

    ... remote sensing instruments; the synthetic aperture radar (SAR) on board the RADARSAT satellite and the Multi-angle Imaging ... ice charts using several data sources including RADARSAT SAR images such as the one shown at left. SAR classifies sea ice types primarily by how the surface and subsurface ...

  6. Ships to the Sea.

    ERIC Educational Resources Information Center

    Department of the Navy, Washington, DC.

    This lesson contains materials for the U.S. Navy Museum's "Ships to the Sea" program. The program is appropriate for students in grades 2-4 and was designed in accordance with local and national social studies standards. The materials introduce students to the world of ship technology and naval terminology. The lesson is presented in five…

  7. The Sea Beside Us

    ERIC Educational Resources Information Center

    Watling, Carol; Hallard Raymond E.

    1974-01-01

    The Sea Beside Us for the Special Child is a project in Delaware with three goals: providing outdoor and overnight experiences for handicapped children; introducing these students to beach, bay, and marsh environments; and increasing the number of special education teachers incorporating seashore studies in their teaching curriculum. (LS)

  8. Modern sea power

    SciTech Connect

    Till, G.

    1987-01-01

    This book provides discussions of political, technical and military aspects of nuclear power. The contents include naval warfare in the nuclear age; politics, money, law and technology; a technological change; implications of technology; sea control; strategic deterrents; amphibious operations, maritime interdiction; inshore operations, naval diplomacy and conclusion.

  9. Egyptian Sea Cave

    ERIC Educational Resources Information Center

    Journal of College Science Teaching, 2005

    2005-01-01

    This brief article describes an archaeological expedition to the Red Sea coast area of Egypt in 2004. Kathryn Bard, an associate professor of archaeology at Boston University, along with her team, discovered the well-preserved cedar timbers of an ancient Egyptian seafaring vessel near the entrance to a large man-made cave. Limestone tablets with

  10. S.E.A.

    ERIC Educational Resources Information Center

    Hawkins, Richard H.

    1976-01-01

    Sea Semester combines a six-week apprenticeship on a sailing ship with an intensive shore preparation component. Through Boston University, students learn marine and nautical sciences before putting some of this information to practice. Students, having completed the shore and sailing components, can enroll in more advanced shore component…

  11. Solomon's Sea and [Pi

    ERIC Educational Resources Information Center

    Simoson, Andrew J.

    2009-01-01

    This paper is a whimsical survey of the various explanations which might account for the biblical passage in I Kings 7:23 that describes a round object--a bronze basin called Solomon's Sea--as having diameter ten cubits and circumference thirty cubits. Can the biblical pi be any number other than 3? We offer seven different perspectives on this…

  12. The Provident Sea

    NASA Astrophysics Data System (ADS)

    Cushing, David H.

    1988-09-01

    The Provident Sea describes the history of fish stock management (including whales and seals). The book traces, on the basis of the original scientific material, the history of the management of "the provident sea" up to recent times when problems of over-exploitation have had dramatic effects upon stocks. The need for management arose mainly from the increasing industrialization of capture. Hence the preindustrial fisheries are covered, in particular the old cod fishery on the Grand Bank and the herring fishery in the North Sea, as an essential background to current problems. The origins of fisheries and whaling science are described, as is the development up to 1965 of the science and institution in fisheries, whaling, and sealing. In the sixties and seventies, certain major fishing nations took a heavy harvest of fish stocks using sophisticated and efficient gathering methods. This in turn led to conflict and one consequence was the "Law of the Sea" conference set up to try and resolve these issues.

  13. Sea Surface Temperature

    EPA Science Inventory

    This indicator presents global mean sea surface temperature (SST) anomalies from 1880 to 2010. SST is a critical physical attribute of marine and coastal ecosystems that directly affects biological and physical process rates, water column stability, and the presence and health...

  14. Egyptian Sea Cave

    ERIC Educational Resources Information Center

    Journal of College Science Teaching, 2005

    2005-01-01

    This brief article describes an archaeological expedition to the Red Sea coast area of Egypt in 2004. Kathryn Bard, an associate professor of archaeology at Boston University, along with her team, discovered the well-preserved cedar timbers of an ancient Egyptian seafaring vessel near the entrance to a large man-made cave. Limestone tablets with…

  15. Harvesting the Sea.

    ERIC Educational Resources Information Center

    Markle, Sandra

    1989-01-01

    Information on commercial fishing is provided, and a board game is described which requires students to watch for ocean signs of good fishing, choose equipment to catch specific types of fish, and consider effects of weather on working at sea. A reproducible copy of the game, with instructions, is included. (IAH)

  16. Alaska and Bering Sea Bloom

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Alaska was relatively clear as was part of the Bering Sea where the aquamarine bloom is still visible in this SeaWiFS image. Credit: Provided by the SeaWiFS Project, NASA/Goddard Space Flight Center, and ORBIMAGE

  17. Sea floor magnetic observatory

    NASA Astrophysics Data System (ADS)

    Korepanov, V.; Prystai, A.; Vallianatos, F.; Makris, J.

    2003-04-01

    The electromagnetic precursors of seismic hazards are widely accepted as strong evidence of the approaching earthquake or volcano eruption. The monitoring of these precursors are of main interest in densely populated areas, what creates serious problems to extract them at the strong industrial noise background. An interesting possibility to improve signal-to-noise ratio gives the installation of the observation points in the shelf zones near the possible earthquake places, what is fairly possible in most seismically active areas in Europe, e. g. in Greece and Italy. The serious restriction for this is the cost of the underwater instrumentation. To realize such experiments it requires the unification of efforts of several countries (e. g., GEOSTAR) or of the funds of some great companies (e. g., SIO magnetotelluric instrument). The progress in electronic components development as well as the appearance of inexpensive watertight glass spheres made it possible to decrease drastically the price of recently developed sea floor magnetic stations. The autonomous vector magnetometer LEMI-301 for sea bed application is described in the report. It is produced on the base of three-component flux-gate sensor. Non-magnetic housing and minimal magnetism of electronic components enable the instrument to be implemented as a monoblock construction where the electronic unit is placed close to the sensor. Automatic circuit provides convenient compensation of the initial field offset and readings of full value (6 digits) of the measured field. Timing by internal clock provides high accuracy synchronization of data. The internal flash memory assures long-term autonomous data storage. The system also has two-axes tilt measurement system. The methodological questions of magnetometer operation at sea bed were studied in order to avoid two types of errors appearing at such experimental cases. First is sea waving influence and second one magnetometer orientation at its random positioning on the sea floor in order to get experimental data in geomagnetic coordinates frames. The analysis executed showed that first error source can not be avoided at shallow water experiments but can be easily taken into account. The special methodology and the developed software allowed to solve the second problem. It was shown that it is possible to reduce the magnetometer data collected in randomly oriented coordinate system at arbitrary position on the sea floor to the data in the frame system connected with geomagnetic coordinates. The parameters of LEMI-302 sea bed magnetometer are discussed and the experimental results of its application are presented. The research work in Ukraine was partly supported by INTAS grant 99-1102.

  18. The Weddell Sea

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Several large, irregularly shaped icebergs are floating in the Weddell Sea, east of the Antarctic Peninsula, in this true-color MODIS image from February 17, 2002. The location of several of the bergs has changed little over the last three months. Compared to an image acquired on November 13, 2001, the berg at the upper right of the image has spun around, but is still hanging around in the same general location. Similar slow-movers can be seen just to the east of the Larsen Ice Shelf, which hugs the eastern coast of the Peninsula. The northernmost of those two bergs is designated A38b; the southernmost one is A38a. These bergs were once part of an iceberg greater than 2,700 square miles that broke off the Ronne Ice Shelf (to the south) back in 1998. While the waters of the Weddell Sea in the area ought to be deep enough to float those bergs, it is possible that they have run aground on a topographic high, or ridge, in the sea floor. However, little is known about the underwater topography of that region, and it is also possible that the bergs are simply so massive that they resist being moved by surface wind or ocean currents. While four years might seem like a long time for an iceberg to hang around, these are certainly no record holders. A berg that broke off the Ross Ice Shelf (on the other side of Antarctica) drifted north and went aground south of Australia. That berg calved in 1987, and hasn't really moved in ten years. While the big bergs have not moved much in the span of time between these images, there is a big difference in the amount of sea ice present in the two images. In general, the rounder chunks of ice are more likely to be seasonal sea ice that forms from the freezing of sea water, while the larger, jagged-edged pieces of ice are more likely to be bergs that broke off an ice shelf at the margin of the continent. It's the height of summer in Antarctica in the February image, and much of the sea ice has melted or drifted away, leaving a relatively large expanse of clear ocean. Credit:

  19. Barents Sea crustal architecture and basin development

    NASA Astrophysics Data System (ADS)

    Faleide, J. I.

    2012-04-01

    The Barents Sea continental shelf is characterized by a complex tectonic history and thus comprises a wide range of crustal and basin architectures that formed in response to different geological processes. Overlapping Paleozoic orogenies (Timanian, Caledonian, Uralian) preceded multiple rift episodes mainly affecting the western Barents Sea and eventual breakup with Greenland to the west and Lomonosov Ridge to the north. Recent work related to the PETROBAR and BarMod projects has provided new details on basin architecture, tectonic and thermal histories, stratigraphy, paleogeography, paleo-water depths and the role of the basement grain in the structuring of the Barents Sea basins. The eastern Barents Sea comprises a wide and deep sag basin that formed by rapid subsidence in Late Permian-Early Triassic times, most likely in response to basin-forming mechanisms other than rifting. The deep East Barents Sea Basin was filled by thick uppermost Permian and Triassic sediments prograding westwards from uplifted source areas mainly in the SE (Urals). In the western Barents Sea we find more typical rift basins formed in response to at least three major post-Caledonian rift phases: Carboniferous, Late Jurassic-Early Cretaceous, and Late Cretaceous-early Paleogene. The rifting activity migrated westwards through successive tectonic phases. Carboniferous rifting affected the entire western Barents Sea and gave rise to NE-SW to N-S trending horst and graben structures following a Caledonian basement grain. These structures were covered by a regional carbonate platform before renewed faulting affected the SW Barents Sea in Late Permian time. The major prograding system reached the western Barents Sea in earliest Triassic time gradually filling in a regional basin of considerable waterdepths. Late Jurassic-Early Cretaceous oblique extension and formation of the deep SW Barents Sea basins was linked to the North Atlantic-Arctic plate tectonic evolution. Regional uplift associated with the Early Cretaceous High Arctic Large Igneous Province gave rise to a depositional system characterized by north to south progradation covering most of the Barents Sea. Volcanic extrusives are preserved in the northern Barents Sea, mainly on Franz Josef Land and eastern Svalbard, while intrusives are found widespread, particularly in the deep East Barents Sea Basin. A Late Cretaceous-Early Paleogene mega-shear system along the western Barents Sea-Svalbard margin (De Geer Zone) linked rifting, breakup and initial opening of the Norwegian-Greenland Sea and the Arctic Eurasia Basin. Narrow pull-apart basins formed within this dominantly shear system, in particular at a releasing bend in the margin SW of Bjørnøya. A restraining bend SW of Svalbard gave rise to the transpressional Spitsbergen Fold-and-Thrust Belt. Compressional structures of different styles are found widespread in the Barents Sea region. The nature and timing of these are difficult to constrain in many areas due to later uplift and erosion, but we expect that there are different causes and timing involved. At the western margin we see evidence of compressional deformation as young as Miocene in age. The entire Barents Shelf was uplifted and eroded during Neogene time and thick fans of Plio-Pleistocene glacial sediments were formed in front of bathymetric troughs characteristic of both the western and northern Barents Sea. Most of the uplift is closely linked to the glacial erosion, but tectonic uplift occurred prior to the glaciations.

  20. Northern Sand Sea

    NASA Technical Reports Server (NTRS)

    2005-01-01

    [figure removed for brevity, see original site]

    Our topic for the weeks of April 4 and April 11 is dunes on Mars. We will look at the north polar sand sea and at isolated dune fields at lower latitudes. Sand seas on Earth are often called 'ergs,' an Arabic name for dune field. A sand sea differs from a dune field in two ways: 1) a sand sea has a large regional extent, and 2) the individual dunes are large in size and complex in form.

    This VIS image was taken at 82 degrees North latitude during Northern spring. The image is completely dominated by dunes. In sand seas, it is very common for a single type of dune to occur, and for a single predominate wind to control the alignment of the dunes.

    Image information: VIS instrument. Latitude 82.2, Longitude 152.5 East (207.5 West). 19 meter/pixel resolution.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

  1. Sea-Level Projections from the SeaRISE Initiative

    NASA Technical Reports Server (NTRS)

    Nowicki, Sophie; Bindschadler, Robert

    2011-01-01

    SeaRISE (Sea-level Response to Ice Sheet Evolution) is a community organized modeling effort, whose goal is to inform the fifth IPCC of the potential sea-level contribution from the Greenland and Antarctic ice sheets in the 21st and 22nd century. SeaRISE seeks to determine the most likely ice sheet response to imposed climatic forcing by initializing an ensemble of models with common datasets and applying the same forcing to each model. Sensitivity experiments were designed to quantify the sea-level rise associated with a change in: 1) surface mass balance, 2) basal lubrication, and 3) ocean induced basal melt. The range of responses, resulting from the multi-model approach, is interpreted as a proxy of uncertainty in our sea-level projections. http://websrv.cs .umt.edu/isis/index.php/SeaRISE_Assessment.

  2. Sea Ice Radiative Forcing, Sea Ice Area, and Climate Sensitivity

    NASA Astrophysics Data System (ADS)

    Caldeira, K.; Cvijanovic, I.

    2014-12-01

    Changes in sea ice cover affect climate sensitivity by modifying albedo and surface heat flux exchange, which in turn affect the absorbed solar radiation at the surface as well as cloud cover, atmospheric water content and poleward atmospheric heat transport. Here, we use a configuration of the Community Earth System Model 1.0.4 with a slab ocean model and a thermodynamic-dynamic sea ice model to investigate the overall net effect of feedbacks associated with the sea ice loss. We analyze the strength of the overall sea ice feedback in terms of two factors: the sensitivity of sea ice area to changes in temperature, and the sensitivity of sea ice radiative forcing to changes in sea ice area. In this model configuration, sea ice area decreases by ~3 × 1012 m2 per K of global warming, while the effective global radiative forcing per unit area of sea ice loss is ~0.1 × 10-12 W m-2. The product of these two terms (~0.3 W m-2 K-1) approximately equals the difference in climate feedback parameter found in simulations with sea ice response (1.05 W m-2 K-1) and simulations without sea ice response (1.31 W m-2 K-1 or 1.35 W m-2 K-1, depending on the method used to disable the changes in sea ice cover). Thus, we find that in our model simulations, sea ice response accounts for about 20% to 22% of the climate sensitivity to an imposed change in radiative forcing. In our model, the additional radiative forcing resulting from a loss of all sea-ice in the "pre-industrial" state is comparable to but somewhat less than the radiative forcing from a doubling of atmospheric CO2 content.

  3. Sea ice/climate studies

    NASA Technical Reports Server (NTRS)

    Parkinson, C. L.

    1988-01-01

    The objectives were to determine and analyze the annual cycle of sea ice extents in the Arctic Ocean and peripheral seas and bays over the period 1973 to 1986, looking in particular for any long term trends; to examine the relationship between local sea ice covers and the surrounding atmosphere and ocean; and to examine sea ice as a potential early indicator of climate change. The work involves creating regional and hemispheric time series of sea ice variables from satellite passive microwave data and analyzing these through various intercomparisons amongst themselves and with oceanographic and atmospheric fields.

  4. North Sea Sediment Dynamics

    NASA Astrophysics Data System (ADS)

    Paetsch, Johannes; Kuehn, Wilfried; Serna, Alexandra; Lahajnar, Niko; Emeis, Kay

    2014-05-01

    The North Sea is a semi-enclosed shelf sea attached to the North-east Atlantic and in its south-eastern part receives significant matter from river discharge and atmospheric deposition: Anthropogenic nutrients, dissolved carbon and organic compounds have elevated pristine background concentrations in the coastal strip of the North Sea since about 250 years as a consequence of intensified agriculture and industrialisation since then, In such a marine environment the legacy of old inputs and the influence of processes in the sediment on the biogeochemistry of the overlying water column increases with decreasing water depth. On the other hand the flux of particulate organic matter into the surface sediment (~15 cm depth) also increases with decreasing water depth or distance from the coast. Both effects are also described by results of ECOHAM-M simulations, the coupled pelagic-benthic ecosystem model that includes a prognostic multi-layer sediment module adopted from the global biogeochemical model HAMOCC as part of the MPI-earth-system model (MPI-ESM).The transfer from deep sea to coastal applications required different adaptations, such as changes in porosity values, in dissolution and organic matter remineralisation rates, and stoichiometries. In the model, two pelagic detritus pools, one slowly sinking with semi-labile organic matter, and one fast sinking with labile organic matter are collected in one sediment pool. After a spin-up of several hundred years the 3d-coupled model for the southern and central North Sea attains equilibrium, where the local inputs and outputs of the pelagic and benthic module are balanced. From this equilibrium state we initialised a realistic decadal run (2000-2009). Analysing the seasonal and interannual model results we found that the variability of sediment efflux in the model is low compared to the more dynamic pelagic system components, but simulated (and observed) sediment pore water profiles clearly show concentration gradients from the coast into the central North Sea. Data on organic matter concentration and quality in surface sediments along a comparable transect suggest that not only the loading with POM decreases with distance to land, but also the reactivity of organic matter, indicated by amino acid composition as a measure of the degree of protein degradation. This ageing or degradation effect can also be seen in a near-shore surface sediment core where the C/N ratio increases with depth, while the relative concentration of labile material in sedimentary organic matter decreases. We discuss how the quality of organic particulate matter could be integrated into the sediment model equations.

  5. The North Sea - A shelf sea in the Anthropocene

    NASA Astrophysics Data System (ADS)

    Emeis, Kay-Christian; van Beusekom, Justus; Callies, Ulrich; Ebinghaus, Ralf; Kannen, Andreas; Kraus, Gerd; Kröncke, Ingrid; Lenhart, Hermann; Lorkowski, Ina; Matthias, Volker; Möllmann, Christian; Pätsch, Johannes; Scharfe, Mirco; Thomas, Helmuth; Weisse, Ralf; Zorita, Eduardo

    2015-01-01

    Global and regional change clearly affects the structure and functioning of ecosystems in shelf seas. However, complex interactions within the shelf seas hinder the identification and unambiguous attribution of observed changes to drivers. These include variability in the climate system, in ocean dynamics, in biogeochemistry, and in shelf sea resource exploitation in the widest sense by societies. Observational time series are commonly too short, and resolution, integration time, and complexity of models are often insufficient to unravel natural variability from anthropogenic perturbation. The North Sea is a shelf sea of the North Atlantic and is impacted by virtually all global and regional developments. Natural variability (from interannual to multidecadal time scales) as response to forcing in the North Atlantic is overlain by global trends (sea level, temperature, acidification) and alternating phases of direct human impacts and attempts to remedy those. Human intervention started some 1000 years ago (diking and associated loss of wetlands), expanded to near-coastal parts in the industrial revolution of the mid-19th century (river management, waste disposal in rivers), and greatly accelerated in the mid-1950s (eutrophication, pollution, fisheries). The North Sea is now a heavily regulated shelf sea, yet societal goals (good environmental status versus increased uses), demands for benefits and policies diverge increasingly. Likely, the southern North Sea will be re-zoned as riparian countries dedicate increasing sea space for offshore wind energy generation - with uncertain consequences for the system's environmental status. We review available observational and model data (predominantly from the southeastern North Sea region) to identify and describe effects of natural variability, of secular changes, and of human impacts on the North Sea ecosystem, and outline developments in the next decades in response to environmental legislation, and in response to increased use of shelf sea space.

  6. Poster: the sea urchin.

    PubMed

    2006-11-10

    The announcement of the sequencing of the genome of the sea urchin Strongylocentrotus purpuratus is the latest glowing chapter in the long history of contributions from sea urchin researchers to fundamental principles of cell biology, developmental biology, and gene regulation. A poster created for the print Science presents a timeline of the past and a glimpse into the next stage of research that is being opened up through genomic insights; a PDF of that poster is available for our subscribers. We have also created, for all site visitors, an interactive version of the poster, including additional images, video, and Web resources. Interactive poster (free; requires Flash 8 or higher). PDF of print poster (subscription required). PMID:17095688

  7. A closing Ligurian Sea?

    NASA Astrophysics Data System (ADS)

    Bethoux, N.; Fréchet, J.; Guyoton, F.; Thouvenot, F.; Cattaneo, M.; Eva, C.; Nicolas, M.; Granet, M.

    1992-06-01

    Two earthquakes occurred in the Ligurian Sea in December 1989 and April 1990. Both were widely felt along the French and Italian Rivieras, thus reminding us of the seismic risk in this region. The significant increase in the number of seismic stations in the area facilitated the study of these two shocks and their related aftershocks. Using different techniques (absolute and relative hypocentral locations, doublet analysis and waveform modeling), we computed accurate hypocentral locations and estimated the location-error range for earthquakes in this area. We also computed the focal mechanisms for both mainshocks, and we present here a synthesis that integrates previous data. The reactivation in compression of the Ligurian Sea sphenochasm is confirmed, which would eventually result in the closing of an aborted oceanic domain. As the seismic activity is clearly restricted to the northern margin, we suggest it locally results from the lateral expulsion of the south-western Alps along the Apulian indenter.

  8. Dead Sea rhodopsins revisited.

    PubMed

    Bodaker, Idan; Suzuki, Marcelino T; Oren, Aharon; Bj, Oded

    2012-12-01

    The Dead Sea is a unique hypersaline ecosystem with near toxic magnesium levels (?2?M), dominance of divalent cations and a slightly acidic pH. Previously, we reported a haloarchaeon related to Halobacterium salinarum to dominate in a microbial bloom that developed in 1992 in the upper water layers of the lake following massive freshwater runoff. Whether this clade also dominated an earlier bloom in 1980-1982 cannot be ascertained as no samples for cultivation-independent analysis were preserved. The presence of the light-driven proton pump bacteriorhodopsin was reported in the 1980-1982 bloom of prokaryotes that had developed in the Dead Sea. To test the hypothesis that bacteriorhodopsin proton pumping may play a major role in determining what type of haloarchaea may dominate in specific bloom conditions, we compared rhodopsin genes recovered from Dead Sea biomass collected in different periods with genes coding for retinal proteins in isolated haloarchaea. Novel bacteriorhodopsin and sensory rhodopsin genes were found in samples collected in 2007 and 2010. The fact that no rhodopsin genes were recovered from samples collected during the 1992 bloom, which was dominated by a single species, suggests that different clades were present in the 1980-1982 and 1992 blooms, and that bacteriorhodopsin proton pumping did not necessarily play a determinative role in the dominance of specific halophiles in the blooms. PMID:23760932

  9. Curonian Spit, Baltic Sea

    NASA Technical Reports Server (NTRS)

    2006-01-01

    On July 25, 2006, the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER), flying on NASA's Terra satellite, captured this image of the Curonian (or Courland)spit, the Curonian Lagoon (also known as the Courland Lagoon) it encloses, and part of the Baltic Sea. Just 3,800 meters (about 12,460 feet) at its widest point, the spit encloses a lagoon of some 1,620 square kilometers (625 square miles). In this image, dark blue indicates deep water, and lighter blue indicates shallow and/or sediment-laden water. Different shades of blue distinguish the deeper Baltic Sea and the shallower Curonian Lagoon. Vegetation appears in varying shades of green, paved surfaces and bare ground appear in shades of beige and gray, and sandy areas appear off-white. Obvious sandy areas appear along the length of the spit. On the Baltic Sea side, a thin off-white band of beach runs the length of the spit; on the Curonian Lagoon side, intermittent beaches carve their way into the narrow strip of land.

  10. Sea-level projections from the SeaRISE initiative

    NASA Astrophysics Data System (ADS)

    nowicki, S.; Bindschadler, R.; SeaRISE Team

    2011-12-01

    SeaRISE (Sea-level Response to Ice Sheet Evolution) is a community organized modeling effort, whose goal is to inform the fifth IPCC of the potential sea-level contribution from the Greenland and Antarctic ice sheets in the 21st and 22nd century. SeaRISE seeks to determine the most likely ice sheet response to imposed climatic forcing by initializing an ensemble of models with common datasets and applying the same forcing to each model. Sensitivity experiments were designed to quantify the sea-level rise associated with a change in: 1) surface mass balance, 2) basal lubrication, and 3) ocean induced basal melt. The range of responses, resulting from the multi-model approach, is interpreted as a proxy of uncertainty in our sea-level projections.

  11. Late Pleistocene Sea Level Stack

    NASA Astrophysics Data System (ADS)

    Spratt, R. M.; Lisiecki, L. E.

    2014-12-01

    Sea level reconstructions have been created using wide variety of proxies and models. The accuracy of individual sea level reconstructions is limited by measurement, noise, local variations in salinity and temperature, and the assumptions particular to each reconstruction. To address these limitations, we have created a sea level stack (average) which increases the signal-to-noise ratio of sea level estimates by combining 5-7 sea level reconstructions over the last 800 kyr. Principal Component analysis (PCA) of seven sea level records from 0-430 kyr ago shows that 82% of the variance in these records is explained by their first principal component (i.e., the stack). Additionally, a stack of just the 5 longer records that extends to 800 kyr closely matches the timing and amplitude of our seven-record mean. We find that the mean sea level estimate for Marine Isotope Stage (MIS) 5e is 0-4 m above modern, and that the standard deviation of individual estimates is 11 m. Mean sea level estimates for MIS 11 are 12-16 m above modern with a standard deviation of 30 m. Due to the large variability between individual reconstructions, our sea level stack may provide more robust sea level estimates than any single technique.

  12. Arctic Sea Ice

    NASA Astrophysics Data System (ADS)

    Stroeve, J. C.; Fetterer, F.; Knowles, K.; Meier, W.; Serreze, M.; Arbetter, T.

    2004-12-01

    Of all the recent observed changes in the Arctic environment, the reduction of sea ice cover stands out most prominantly. Several independent analysis have established a trend in Arctic ice extent of -3% per decade from the late 1970s to the late 1990s, with a more pronounced trend in summer. The overall downward trend in ice cover is characterized by strong interannual variability, with a low September ice extent in one year typically followed by recovery the next September. Having two extreme minimum years, such as what was observed in 2002 and 2003 is unusual. 2004 marks the third year in a row of substantially below normal sea ice cover in the Arctic. Early summer 2004 appeared unusual in terms of ice extent, with May a record low for the satellite period (1979-present) and June also exhibiting below normal ice extent. August 2004 extent is below that of 2003 and large reductions in ice cover are observed once again off the coasts of Siberia and Alaska and the Greenland Sea. Neither the 2002 or 2003 anomaly appeared to be strongly linked to the positive phase of the Arctic Oscillation (AO) during the preceding winter. Similarly, the AO was negative during winter 2003/2004. In the previous AO framework of Rigor et al (2002), a positive winter AO implied preconditioning of the ice cover to extensive summer decay. In this hypothesis, the AO does not explain all aspects of the recent decline in Arctic ice cover, such as the extreme minima of 2002, 2003 and 2004. New analysis by Rigor and Wallace (2004) suggest that the very positive AO state from 1989-1995 can explain the recent sea ice minima in terms of changes in the Arctic surface wind field associated with the previous high AO state. However, it is also reasonable to expect that a general decrease in ice thickness accompanying warming would manifest itself as greater sensitivity of the ice pack to wind forcings and albedo feedbacks. The decrease in multiyear ice and attendant changes in ice thickness distribution could in turn precondition the Arctic ice cover to further reductions in the subsequent summer(s) regardless if the summer temperatures were anomalously warm. The NSIDC Sea Ice Index (http://nsidc.org/data/seaice_index/) can be used to view trends and anomalies from 1979 on.

  13. Experiencing the Full Research Process at Sea Education Association (SEA)

    NASA Astrophysics Data System (ADS)

    Harris, S. E.; Joyce, P.; Jaroslow, G.; Graziano, L.; Lea, C.; Witting, J.; Bower, A.

    2003-12-01

    While some undergraduate research experiences include only a small piece of the research process, students attending Sea Education Association's SEA Semester complete all aspects of oceanographic research in an intensive 12 week program that earns a full semester's credit. In the first half of the program, students read and discuss background literature on a subject, ask questions, pose hypotheses, and develop a written research proposal, which they defend orally. The second half of the course takes place at sea on one of SEA's state-of-the-art oceanographic research vessels where students carry out their sampling plans, analyze samples and data, write a final paper and present their results before the vessel reaches port, completing the course. At sea, students participate in sample collection and analysis for all student projects in addition to learning the general oceanography along their cruise track. This structure exposes students to the realities of research from start to finish and allows them to take full ownership of their projects. In addition to honing writing, public speaking, and problem-solving skills, students learn that research requires dedication, flexibility, and creativity, particularly when their results are unexpected or negate their hypothesis. SEA's undergraduate research program has been developing since 1971. Over that time, SEA has collected an extensive historical oceanographic database in the western Atlantic and Caribbean, plus Pacific data since 2001. This database is available to both students and outside research scientists. Collaborations with scientists outside SEA enhance the student experience and help facilitate oceanographic research by providing "ship-of-opportunity" sampling in remote locations. SEA Semester provides an excellent model for undergraduate research experiences with over 5000 alumni, about 30% of whom enter graduate school. About half the students in SEA's undergraduate programs are non-science majors. Although their experience at SEA may be their only hands-on exposure to scientific research, they take away an understanding of the process and an ability to think critically about scientific problems.

  14. Survey maps Philippine Sea structures

    NASA Astrophysics Data System (ADS)

    Ohara, Yasuhiko; Kasuga, Shigeru; Okino, Kyoko; Kato, Yukihiro

    Detailed structural images of two basins in the Philippine Sea and related data collected by the Japanese Continental Shelf Surveys Project are increasing our understanding of how back-arc basins evolve. The area surveyed covers the southeastern East China Sea, the northern Philippine Sea, and the westernmost Northwest Pacific Basin (Figure 1). One purpose of the survey is to gather information to help define Japan's legal continental shelf in the context of the United Nations Convention on the Law of the Sea, which became effective in 1994.

  15. Sea Otter, River Otter. The Wonder Series.

    ERIC Educational Resources Information Center

    Robinson, Sandra Chisholm

    This curriculum guide is all about otters and provides information on both sea and river otters. Included are activities related to the diet of sea otters, the adaptations sea otters have made to live in the sea, their tool-using abilities, where they live and how to spot them, comparative anatomy of sea and river otters, and otter movement. The

  16. Sea Otter, River Otter. The Wonder Series.

    ERIC Educational Resources Information Center

    Robinson, Sandra Chisholm

    This curriculum guide is all about otters and provides information on both sea and river otters. Included are activities related to the diet of sea otters, the adaptations sea otters have made to live in the sea, their tool-using abilities, where they live and how to spot them, comparative anatomy of sea and river otters, and otter movement. The…

  17. Sea Urchin Morphogenesis.

    PubMed

    McClay, David R

    2016-01-01

    In the sea urchin morphogenesis follows extensive molecular specification. The specification controls the many morphogenetic events and these, in turn, precede patterning steps that establish the larval body plan. To understand how the embryo is built it was necessary to understand those series of molecular steps. Here an example of the historical sequence of those discoveries is presented as it unfolded over the last 50 years, the years during which major progress in understanding development of many animals and plants was documented by CTDB. In sea urchin development a rich series of experimental studies first established many of the phenomenological components of skeletal morphogenesis and patterning without knowledge of the molecular components. The many discoveries of transcription factors, signals, and structural proteins that contribute to the shape of the endoskeleton of the sea urchin larva then followed as molecular tools became available. A number of transcription factors and signals were discovered that were necessary for specification, morphogenesis, and patterning. Perturbation of the transcription factors and signals provided the means for assembling models of the gene regulatory networks used for specification and controlled the subsequent morphogenetic events. The earlier experimental information informed perturbation experiments that asked how patterning worked. As a consequence it was learned that ectoderm provides a series of patterning signals to the skeletogenic cells and as a consequence the skeletogenic cells secrete a highly patterned skeleton based on their ability to genotypically decode the localized reception of several signals. We still do not understand the complexity of the signals received by the skeletogenic cells, nor do we understand in detail how the genotypic information shapes the secreted skeletal biomineral, but the current knowledge at least outlines the sequence of events and provides a useful template for future discoveries. PMID:26969970

  18. The Sea Around Us

    NASA Astrophysics Data System (ADS)

    Carson, Rachel L.

    1991-12-01

    Published in 1951, The Sea Around Us is one of the most remarkably successful books ever written about the natural world. Rachel Carson's rare ability to combine scientific insight with moving, poetic prose catapulted her book to first place on The New York Times best-seller list, where it enjoyed wide attention for thirty-one consecutive weeks. It remained on the list for more than a year and a half and ultimately sold well over a million copies, has been translated into 28 languages, inspired an Academy Award-winning documentary, and won both the 1952 National Book Award and the John Burroughs Medal. This classic work remains as fresh today as when it first appeared. Carson's writing teems with stunning, memorable images--the newly formed Earth cooling beneath an endlessly overcast sky; the centuries of nonstop rain that created the oceans; giant squids battling sperm whales hundreds of fathoms below the surface; and incredibly powerful tides moving 100 billion tons of water daily in the Bay of Fundy. Quite simply, she captures the mystery and allure of the ocean with a compelling blend of imagination and expertise. Reintroducing a classic work to a whole new generation of readers, this Special Edition features a new chapter written by Jeffrey Levinton, a leading expert in marine ecology, that brings the scientific side of The Sea Around Us completely up to date. Levinton incorporates the most recent thinking on continental drift, coral reefs, the spread of the ocean floor, the deterioration of the oceans, mass extinction of sea life, and many other topics. In addition, acclaimed nature writer Ann Zwinger has contributed a brief foreword. Today, with the oceans endangered by the dumping of medical waste and ecological disasters such as the Exxon oil spill in Alaska, this illuminating volume provides a timely reminder of both the fragility and the importance of the ocean and the life that abounds within it. Anyone who loves the sea, or who is concerned about our natural environment, will want to read this classic work.

  19. Two Sea-Level Challenges

    NASA Astrophysics Data System (ADS)

    Galvin, C.

    2008-12-01

    "No place on the sandy ocean shores of the world has been shown to be eroding because of sea level rise." This statement appeared nearly 19 years ago in bold print at the top of the page in a brief article published in Shore and Beach (Galvin,1990). The term "sea level rise" was defined in 1990 as follows: "In this statement, "sea level rise" has the meaning that the average person on the street usually attaches to that term. That is, sea level is rising; not, as in some places like the Mississippi River delta, land level is sinking." While still a subject of controversy, it is now (2008) increasingly plausible (Tornqvist et al,2008) that damage from Hurricane Katrina was significantly worse on the Mississippi River delta because floodwaters exploited wetlands and levees whose elevations had been lowered by decades of compaction in the underlying soil. (1) "Sea level" commonly appears in the literature as "relative sea level rise", occurring that way in 711 publications between 1980 and 2009 (GeoRef database on 8 Sep 08). "Relative sea level rise" does not appear in the 2005 AGI Glossary. The nearest Glossary term is "relative change in sea level", but that term occurs in only 12 publications between 1980 and 2009. The Glossary defines this term in a sequence stratigraphy sense, which infers that "relative sea level rise" is the sum of bottom subsidence and eustatic sea level rise. In plain English, "relative sea level rise" means "water depth increase". For present day coastal environments, "relative sea level rise" is commonly used where eustatic sea level rise is less than subsidence, that is, where the magnitude of actual sea level rise is smaller than the magnitude of subsidence. In that situation, "relative sea level rise" misleads both the average person and the scientist who is not a coastal geologist. Thus, the first challenge is to abandon "relative sea level rise" in favor of "water depth increase", in order that the words accurately descibe what happens. It would further clarify popular understanding if the term "actual sea level rise" were used in place of "eustatic sea level rise". (2)Geologists have approximated the the practice of paleontologists and biologists in establishing type examples of important geological features. This is a useful practice. A graduate geologist holds in mind clear conceptions of "beach cusps", "drumlin fields", "birdfoot deltas", and "igneous sills" based on seeing field examples accepted by professional geologists as representative of these features. However, although publications frequently report that sea level rise erodes a particular beach, no one identifies a type beach where that cause has been proven to produce the alleged effect. At the type beach, it is necessary to show that sea level is rising, and that the beach erodes primarily from this sea level rise, rather than from interrupted longshore transport. Thus, the second challenge is to identify a type ocean beach proven to erode because of sea level rise.

  20. 50 CFR 697.12 - At-sea sea sampler/observer coverage.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 50 Wildlife and Fisheries 13 2014-10-01 2014-10-01 false At-sea sea sampler/observer coverage. 697... MANAGEMENT General Provisions § 697.12 At-sea sea sampler/observer coverage. (a) The Regional Administrator...-approved sea sampler/observer. If requested by the Regional Administrator to carry a sea...

  1. 50 CFR 697.12 - At-sea sea sampler/observer coverage.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 50 Wildlife and Fisheries 13 2012-10-01 2012-10-01 false At-sea sea sampler/observer coverage. 697... MANAGEMENT General Provisions § 697.12 At-sea sea sampler/observer coverage. (a) The Regional Administrator...-approved sea sampler/observer. If requested by the Regional Administrator to carry a sea...

  2. 50 CFR 697.12 - At-sea sea sampler/observer coverage.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 50 Wildlife and Fisheries 11 2011-10-01 2011-10-01 false At-sea sea sampler/observer coverage. 697... MANAGEMENT General Provisions § 697.12 At-sea sea sampler/observer coverage. (a) The Regional Administrator...-approved sea sampler/observer. If requested by the Regional Administrator to carry a sea...

  3. 50 CFR 697.12 - At-sea sea sampler/observer coverage.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 50 Wildlife and Fisheries 9 2010-10-01 2010-10-01 false At-sea sea sampler/observer coverage. 697... MANAGEMENT General Provisions § 697.12 At-sea sea sampler/observer coverage. (a) The Regional Administrator...-approved sea sampler/observer. If requested by the Regional Administrator to carry a sea...

  4. Sea ice terminology

    SciTech Connect

    Not Available

    1980-09-01

    A group of definitions of terms related to sea ice is presented, as well as a graphic representation of late winter ice zonation of the Beaufort Sea Coast. Terms included in the definition list are belt, bergy bit, bight, brash ice, calving, close pack ice, compacting, compact pack ice, concentration, consolidated pack ice, crack, diffuse ice edge, fast ice, fast-ice boundary, fast-ice edge, first-year ice, flaw, flaw lead, floe, flooded ice, fractured, fractured zone, fracturing, glacier, grey ice, grey-white ice, growler, hummock, iceberg, iceberg tongue, ice blink, ice boundary, ice cake, ice edge, ice foot, ice free, ice island, ice shelf, large fracture, lead, medium fracture, multiyear ice, nilas, old ice, open pack ice, open water, pack ice, polar ice, polynya, puddle, rafted ice, rafting, ram, ridge, rotten ice, second-year ice, shearing, shore lead, shore polynya, small fracture, strip, tabular berg, thaw holes, very close pack ice, very open pack ice, water sky, young coastal ice, and young ice.

  5. A Silurian sea spider.

    PubMed

    Siveter, Derek J; Sutton, Mark D; Briggs, Derek E G; Siveter, David J

    2004-10-21

    Pycnogonids (sea spiders) are marine arthropods numbering some 1,160 extant species. They are globally distributed in depths of up to 6,000 metres, and locally abundant; however, their typically delicate form and non-biomineralized cuticle has resulted in an extremely sparse fossil record that is not accepted universally. There are two opposing views of their phylogenetic position: either within Chelicerata as sister group to the euchelicerates, or as a sister taxon to all other euarthropods. The Silurian Herefordshire Konservat-Lagerstatte in England (approximately 425 million years (Myr) bp) yields exceptionally preserved three-dimensional fossils that provide unrivalled insights into the palaeobiology of a variety of invertebrates. The fossils are preserved as calcitic void in-fills in carbonate concretions within a volcaniclastic horizon, and are reconstructed digitally. Here we describe a new pycnogonid from this deposit, which is the oldest adult sea spider by approximately 35 Myr and the most completely known fossil species. The large chelate first appendage is consistent with a chelicerate affinity for the pycnogonids. Cladistic analyses place the new species near the base of the pycnogonid crown group, implying that the latter had arisen by the Silurian period. PMID:15496921

  6. Sea modeling and rendering

    NASA Astrophysics Data System (ADS)

    Cathala, Thierry; Latger, Jean

    2010-10-01

    More and more defence and civil applications require simulation of marine synthetic environment. Currently, the "Future Anti-Surface-Guided-Weapon" (FASGW) or "anti-navire léger" (ANL) missile needs this kind of modelling. This paper presents a set of technical enhancement of the SE-Workbench that aim at better representing the sea profile and the interaction with targets. The operational scenario variability is a key criterion: the generic geographical area (e.g. Persian Gulf, coast of Somalia,...), the type of situation (e.g. peace keeping, peace enforcement, anti-piracy, drug interdiction,...)., the objectives (political, strategic, or military objectives), the description of the mission(s) (e.g. antipiracy) and operation(s) (e.g. surveillance and reconnaissance, escort, convoying) to achieve the objectives, the type of environment (Weather, Time of day, Geography [coastlines, islands, hills/mountains]). The paper insists on several points such as the dual rendering using either ray tracing [and the GP GPU optimization] or rasterization [and GPU shaders optimization], the modelling of sea-surface based on hypertextures and shaders, the wakes modelling, the buoyancy models for targets, the interaction of coast and littoral, the dielectric infrared modelling of water material.

  7. Greenland Sea observations

    SciTech Connect

    Gudmandsen, P.; Mortensen, H.B.; Pedersen, L.T.; Skriver, H.; Minnett, P.

    1992-12-31

    ERS-1 SAR data have been acquired over the Greenland Sea and Fram Strait during two periods, the Ice Phase of three-day repeat cycle from January to March 1992 and a one-month period in the 35-day repeat cycle from 16 July to 15 August 1992. Most data became available by way of the Broadband Data Dissemination System, i.e. with a spatial resolution of about 100 m. With these data various algorithms have been tested to derive sea ice parameters such as ice extent, ice concentration and ice displacement. In the latter period data were collected to support the activities of a research vessel in the area mainly related to the large polynyas that form east and north of Greenland. The formation of polynyas could clearly be outlined but also other phenomena were observed related to the influence of wind streets and gravity waves associated with the atmospheric boundary layer. The data will have to be studied further including full-resolution data to substantiate the conclusions arrived at.

  8. Spectacled Eiders Wintering in Northern Bering Sea

    Large flock of Spectacled Eiders aggregated in a sea ice lead in the northern Bering Sea, south of St. Lawrence Island, Alaska.  Aerial photograph from a helicopter deployed from the USCG Cutter Polar Sea. ...

  9. Spectacled Eiders Wintering in Northern Bering Sea

    Large flock of Spectacled Eiders aggregated in a sea ice lead in the northern Bering Sea, south of St. Lawrence Island, Alaska.  Aerial photograph from a helicopter deployed from the USCG Cutter Polar Sea....

  10. Spectacled Eiders Wintering in Northern Bering Sea

    Large flock of Spectacled Eiders aggregated in a sea ice lead at sunset in the northern Bering Sea, south of St. Lawrence Island, Alaska.  Aerial photograph from a helicopter deployed from the USCG Cutter Polar Sea....

  11. ROC Sampling Deep Sea Urchin

    Images of the remotely operated vehicle Jason2 sampling a sea urchin in a deep sea mussel community found near a gas seep on the U.S. outer continental shelf. Images courtesy Deepwater Canyons 2013 - Pathways to the Abyss expedition, NOAA-OER/BOEM/USGS....

  12. The Law of the Sea

    ERIC Educational Resources Information Center

    Levy, Jean-Pierre

    1978-01-01

    Recounts problems related to the law of the sea and suggests that these problems could be dealt with in the classroom in an interdisciplinary manner. Problems include pollution control, fishing rights, development of deep sea mineral deposits, and shore access. (Author/DB)

  13. Arctic Sea ice model sensitivities.

    SciTech Connect

    Peterson, Kara J.; Bochev, Pavel Blagoveston; Paskaleva, Biliana Stefanova

    2010-12-01

    Arctic sea ice is an important component of the global climate system and, due to feedback effects, the Arctic ice cover is changing rapidly. Predictive mathematical models are of paramount importance for accurate estimates of the future ice trajectory. However, the sea ice components of Global Climate Models (GCMs) vary significantly in their prediction of the future state of Arctic sea ice and have generally underestimated the rate of decline in minimum sea ice extent seen over the past thirty years. One of the contributing factors to this variability is the sensitivity of the sea ice state to internal model parameters. A new sea ice model that holds some promise for improving sea ice predictions incorporates an anisotropic elastic-decohesive rheology and dynamics solved using the material-point method (MPM), which combines Lagrangian particles for advection with a background grid for gradient computations. We evaluate the variability of this MPM sea ice code and compare it with the Los Alamos National Laboratory CICE code for a single year simulation of the Arctic basin using consistent ocean and atmospheric forcing. Sensitivities of ice volume, ice area, ice extent, root mean square (RMS) ice speed, central Arctic ice thickness,and central Arctic ice speed with respect to ten different dynamic and thermodynamic parameters are evaluated both individually and in combination using the Design Analysis Kit for Optimization and Terascale Applications (DAKOTA). We find similar responses for the two codes and some interesting seasonal variability in the strength of the parameters on the solution.

  14. Probability of sea level rise

    SciTech Connect

    Titus, J.G.; Narayanan, V.K.

    1995-10-01

    The report develops probability-based projections that can be added to local tide-gage trends to estimate future sea level at particular locations. It uses the same models employed by previous assessments of sea level rise. The key coefficients in those models are based on subjective probability distributions supplied by a cross-section of climatologists, oceanographers, and glaciologists.

  15. Neutrino sea scope takes shape

    NASA Astrophysics Data System (ADS)

    Cartlidge, Edwin

    2016-03-01

    A consortium of European physicists building a vast neutrino detector on the floor of the Mediterranean Sea has unveiled the science it will carry out. The Cubic Kilometre Neutrino Telescope (KM3NeT) will use strings of radiation detectors arranged in a 3D network to measure the light emitted when neutrinos very occasionally interact with the surrounding sea water.

  16. Heat and freshwater budgets of the Nordic seas computed from atmospheric reanalysis and ocean observations

    NASA Astrophysics Data System (ADS)

    Segtnan, O. H.; Furevik, T.; Jenkins, A. D.

    2011-11-01

    The heat and freshwater budgets of the Nordic seas are computed from atmospheric reanalysis data and ocean observations, mainly taken during the period 1990-1999. The total heat loss is 198 TW and the freshwater gain 52 mSv (1 Sv = 106 m3 s-1), with residuals equal to 1 TW and 3 mSv, respectively. Budgets are also computed for three subregions within the Nordic seas: the Norwegian Sea, the Barents Sea and the Greenland/Iceland Sea. Without accounting for transfer of heat and freshwater across the Arctic Front, which separates the Greenland/Iceland Sea from the Norwegian Sea, the residuals of the heat and freshwater budgets range from -36 TW to 34 TW and from -16 mSv to 19 mSv, respectively. To close the budgets of all subregions cross-frontal fluxes of -35 TW and 17 mSv, caused either by eddy shedding along the Arctic Front or ocean currents not accounted for, must be included. Combined with observations of the average temperature and salinity on both sides of the Arctic Front these values indicate a rate of cross-frontal water exchange of approximately 4 Sv. The most intense water mass modifications occur in the Norwegian Sea, where ocean heat loss and freshwater input are equal to 119 TW and 41 mSv, respectively.

  17. Fire in the Sea

    NASA Astrophysics Data System (ADS)

    Friedrich, Walter L.

    2000-05-01

    The legend of the lost city of Atlantis has captivated the human imagination for centuries. Did this city actually exist, and, if so, what happened to it? Was it destroyed in the greatest cataclysmic event of the Bronze Age? While the truth behind the legend of Atlantis may never be known, Fire in the Sea tells the story of one of the largest and most devastating natural disasters of classical history that may also hold vital clues to the possible existence and fate of the lost city. In vivid prose, author Walter L. Friedrich describes the eruption of the Greek island of Santorini, or Thera, sometime in the 17th or 16th century BC. This eruption, perhaps one of the largest explosions ever witnessed by humankind, sent a giant cloud of volcanic ash into the air that eventually covered settlements on the island. Friedrich relates how this event forever altered the course of civilization in the region, and inspired a mystery that has fired humanity's imagination ever since. More than 160 elegant, full-color photographs and vivid prose capture the beauty, the geology, archaeology, history, peoples and environmental setting of Santorini. Fire in the Sea will readily appeal to the general reader interested in natural catastrophies as well as the beauty of the region. It will also enchant anyone who has ever dreamt about uncovering the mystery of the legend of Atlantis. Walter Friedrich is currently an associate professor at the Department of Earth Sciences, University of Aarhus, Denmark. He has visited Santorini at least 35 times since 1975 and has published numerous scientific articles in such international journals as Nature, Lethaia, Spektrum der Wissenschaft, and other publications.

  18. Arctic Sea Ice Predictability and the Sea Ice Prediction Network

    NASA Astrophysics Data System (ADS)

    Wiggins, H. V.; Stroeve, J. C.

    2014-12-01

    Drastic reductions in Arctic sea ice cover have increased the demand for Arctic sea ice predictions by a range of stakeholders, including local communities, resource managers, industry and the public. The science of sea-ice prediction has been challenged to keep up with these developments. Efforts such as the SEARCH Sea Ice Outlook (SIO; http://www.arcus.org/sipn/sea-ice-outlook) and the Sea Ice for Walrus Outlook have provided a forum for the international sea-ice prediction and observing community to explore and compare different approaches. The SIO, originally organized by the Study of Environmental Change (SEARCH), is now managed by the new Sea Ice Prediction Network (SIPN), which is building a collaborative network of scientists and stakeholders to improve arctic sea ice prediction. The SIO synthesizes predictions from a variety of methods, including heuristic and from a statistical and/or dynamical model. In a recent study, SIO data from 2008 to 2013 were analyzed. The analysis revealed that in some years the predictions were very successful, in other years they were not. Years that were anomalous compared to the long-term trend have proven more difficult to predict, regardless of which method was employed. This year, in response to feedback from users and contributors to the SIO, several enhancements have been made to the SIO reports. One is to encourage contributors to provide spatial probability maps of sea ice cover in September and the first day each location becomes ice-free; these are an example of subseasonal to seasonal, local-scale predictions. Another enhancement is a separate analysis of the modeling contributions. In the June 2014 SIO report, 10 of 28 outlooks were produced from models that explicitly simulate sea ice from dynamic-thermodynamic sea ice models. Half of the models included fully-coupled (atmosphere, ice, and ocean) models that additionally employ data assimilation. Both of these subsets (models and coupled models with data assimilation) have a far narrower spread in their prediction, indicating that the results of these more sophisticated methods are converging. Here we summarize and synthesize the 2014 contributions to the SIO, highlight the important questions and challenges that remain to be addressed, and present data on stakeholder uses of the SIO and related SIPN products.

  19. Contrasts in Arctic shelf sea-ice regimes and some implications: Beaufort Sea versus Laptev Sea

    USGS Publications Warehouse

    Reimnitz, E.; Dethleff, D.; Nurnberg, D.

    1994-01-01

    The winter ice-regime of the 500 km) from the mainland than in the Beaufort Sea. As a result, the annual freeze-up does not incorporate old, deep-draft ice, and with a lack of compression, such deep-draft ice is not generated in situ, as on the Beaufort Sea shelf. The Laptev Sea has as much as 1000 km of fetch at the end of summer, when freezing storms move in and large (6 m) waves can form. Also, for the first three winter months, the polynya lies inshore at a water depth of only 10 m. Turbulence and freezing are excellent conditions for sediment entrainment by frazil and anchor ice, when compared to conditions in the short-fetched Beaufort Sea. We expect entrainment to occur yearly. Different from the intensely ice-gouged Beaufort Sea shelf, hydraulic bedforms probably dominate in the Laptev Sea. Corresponding with the large volume of ice produced, more dense water is generated in the Laptev Sea, possibly accompanied by downslope sediment transport. Thermohaline convection at the midshelf polynya, together with the reduced rate of bottom disruption by ice keels, may enhance benthic productivity and permit establishment of open-shelf benthic communities which in the Beaufort Sea can thrive only in the protection of barrier islands. Indirect evidence for high benthic productivity is found in the presence of walrus, who also require year-round open water. By contrast, lack of a suitable environment restricts walrus from the Beaufort Sea, although over 700 km farther to the south. We could speculate on other consequences of the different ice regimes in the Beaufort and Laptev Seas, but these few examples serve to point out the dangers of exptrapolating from knowledge gained in the North American Arctic to other shallow Arctic shelf settings. ?? 1994.

  20. TOC and satellite-sensed chlorophyll and primary production at the Arctic Front in the Nordic Seas

    NASA Astrophysics Data System (ADS)

    Brsheim, Knut Yngve; Milutinovi?, Svetlana; Drinkwater, Kenneth F.

    2014-11-01

    In the Arctic Front region south of Jan Mayen, vertical profiles of Total Organic Carbon (TOC) and hydrographic variables were measured during 3 weeks in June 2007. From time series of satellite-sensed chlorophyll, it was determined that the field studies took place in the aftermath of the culmination of the spring bloom, both on the Arctic (Icelandic Sea) and Atlantic (Norwegian Sea) sides of the Arctic Front. TOC in the upper 50 m was on average 60.9 7.6 ?M C on the Arctic side and 62.3 6.8 ?M C on the Atlantic side. Average in situ fluorescence was higher on the Atlantic side. Annual primary production calculated from satellite imagery showed no enhancement at the Front. To place the Frontal measurements in a larger perspective, satellite imagery over the entire Nordic (Greenland-Icelandic-Norwegian) Seas between 1998 and 2012 were studied. They showed that north of Jan Mayen the spring blooms normally last longer and culminate later with a higher concentration of chlorophyll at the peak in the colder water on the west side of the Front than in the Norwegian Sea. In the year of our expedition, the maximal concentration of satellite-sensed chlorophyll at spring bloom was three times higher in the central Greenland Sea than in the Norwegian Sea. Along the Arctic Front the maximal concentration of satellite sensed chlorophyll was always lower than in the central basins both west and east of the Front. The ordinal date of maximal spring bloom concentration of chlorophyll was negatively correlated with the maximal spring bloom chlorophyll concentration in the Norwegian and Icelandic Seas, but uncorrelated in the Greenland Sea. Interannual variation of primary production and maximal chlorophyll concentration was larger in the Greenland Sea then in the Icelandic and Norwegian Seas and we hypothesize that some of this variation is influenced by difference in energy efficiency between phototrophs and heterotrophs at low temperatures.

  1. The cause of Barents Sea biomass dynamics

    NASA Astrophysics Data System (ADS)

    Yndestad, Harald

    2004-01-01

    The fluctuations of the biomasses in the Barents Sea have been poorly understood and caused problems in biomass management. Better long-term forecasting is thus crucial for an economical and sustainable utilization of the biomass. The present paper presents a wavelet analysis of the Kola temperature series and the biomass time series of Barents Sea Shrimp ( Pandalus borealis), Barents Sea capelin ( Mallotus villosus), Norwegian spring spawning herring ( Clupea harengus), Northeast Arctic cod ( Gadus morhua), and Northeast Arctic haddock ( Melanogrammus aeglefinus). The wavelet shows a close relation between the 18.6-year lunar nodal tide and dominant temperature cycles in the Kola temperature series. It also shows that all biomass time series are correlated to dominant cycles of 18.6/3=6.2, 18.6 and 3∗18.6=55.8 years in the Kola section. This indicates that fluctuations of the temperature and the biomass in the Barents Sea are a deterministic process caused by the lunar nodal cycle. The close relation to the stationary 18.6-year lunar tide opens new possibilities for better forecasting and long-term management. The deterministic relation between biomass growth and the Kola cycles opens a possibility of more optimal management in short-term periods of 6 years, medium-term management of 18 years and long-term management of 55-75 years. The stationary biomass cycles can be represented by a simple phase-clock which indicates the current state of the biomass. This method represents a new possibility of long-term biomass forecasting.

  2. Sea Star Succumbing to Sea Star Wasting Disease

    Unlike their smiling cartoon brethren on television, since 2013, real-life sea stars have been suffering from a wasting disease epidemic in which they lose limbs and literally disintegrate in a matter of days. ...

  3. Iodine emissions from the sea ice of the Weddell Sea

    NASA Astrophysics Data System (ADS)

    Atkinson, H. M.; Huang, R.-J.; Chance, R.; Roscoe, H. K.; Hughes, C.; Davison, B.; Schönhardt, A.; Mahajan, A. S.; Saiz-Lopez, A.; Hoffmann, T.; Liss, P. S.

    2012-11-01

    Iodine compounds were measured above, below and within the sea ice of the Weddell Sea during a cruise in 2009, to make progress in elucidating the mechanism of local enhancement and volatilisation of iodine. I2 mixing ratios of up to 12.4 pptv were measured 10 m above the sea ice, and up to 31 pptv was observed above surface snow on the nearby Brunt Ice Shelf - large amounts. Atmospheric IO of up to 7 pptv was measured from the ship, and the average sum of HOI and ICl was 1.9 pptv. These measurements confirm the Weddell Sea as an iodine hotspot. Average atmospheric concentrations of CH3I, C2H5I, CH2ICl, 2-C3H7I, CH2IBr and 1-C3H7I were each 0.2 pptv or less. On the Brunt Ice Shelf, enhanced concentrations of CH3I and C2H5I (up to 0.5 and 1 pptv respectively) were observed in firn air, with a diurnal profile that suggests the snow may be a source. In the sea ice brine, iodocarbons concentrations were over 10 times those of the sea water below. The sum of iodide + iodate was depleted in sea ice samples, suggesting some missing iodine chemistry. Flux calculations suggest I2 dominates the iodine atom flux to the atmosphere, but models cannot reconcile the observations and suggest either a missing iodine source or other deficiencies in our understanding of iodine chemistry. The observation of new particle formation, consistent with the model predictions, strongly suggests an iodine source. This combined study of iodine compounds is the first of its kind in this unique region of sea ice rich in biology and rich in iodine chemistry.

  4. Iodine emissions from the sea ice of the Weddell Sea

    NASA Astrophysics Data System (ADS)

    Atkinson, H. M.; Huang, R.-J.; Chance, R.; Roscoe, H. K.; Hughes, C.; Davison, B.; Schönhardt, A.; Mahajan, A. S.; Saiz-Lopez, A.; Hoffmann, T.; Liss, P. S.

    2012-05-01

    Iodine compounds were measured above, below and within the sea ice of the Weddell Sea during a cruise in 2009, to elucidate the mechanism of local enhancement and volatilisation of iodine. I2 mixing ratios of up to 12.4 pptv were measured 10 m above the sea ice, and up to 31 pptv was observed above surface snow on the nearby Brunt Ice Shelf - large amounts. Atmospheric IO of up to 7 pptv was measured from the ship, and the average sum of HOI and ICl was 1.9 pptv. These measurements confirm the Weddell Sea as an iodine hotspot. Average atmospheric concentrations of CH3I, C2H5I, CH2ICl, 2-C3H7I, CH2IBr and 1-C3H7I were each 0.2 pptv or less. On the Brunt Ice Shelf, enhanced concentrations of CH3I and C2H5I (up to 0.5 and 1 pptv, respectively) were observed in firn air, with a diurnal profile that suggests the snow may be a source. In the sea ice brine, iodocarbons concentrations were over 10 times those of the sea water below. The sum of iodide + iodate was depleted in sea ice samples, suggesting some missing iodine chemistry. Flux calculations suggest I2 dominates the iodine atom flux to the atmosphere, but models cannot reconcile the observations and suggest either a missing iodine source or other deficiencies in our understanding of iodine chemistry. The observation of new particle formation, consistent with the model predictions, strongly suggests an iodine source. This combined study of iodine compounds is the first of its kind in this unique region of sea ice rich in biology and rich in iodine chemistry.

  5. Influences of sea ice on eastern Bering Sea phytoplankton

    NASA Astrophysics Data System (ADS)

    Zhou, Qianqian; Wang, Peng; Chen, Changping; Liang, Junrong; Li, Bingqian; Gao, Yahui

    2015-03-01

    The influence of sea ice on the species composition and cell density of phytoplankton was investigated in the eastern Bering Sea in spring 2008. Diatoms, particularly pennate diatoms, dominated the phytoplankton community. The dominant species were Grammonema islandica (Grunow in Van Heurck) Hasle, Fragilariopsis cylindrus (Grunow) Krieger, F. oceanica (Cleve) Hasle, Navicula vanhoeffenii Gran, Thalassiosira antarctica Comber, T. gravida Cleve, T. nordenskiöeldii Cleve, and T. rotula Meunier. Phytoplankton cell densities varied from 0.08×104 to 428.8×104 cells/L, with an average of 30.3×104 cells/L. Using cluster analysis, phytoplankton were grouped into three assemblages defined by ice-forming conditions: open water, ice edge, and sea ice assemblages. In spring, when the sea ice melts, the phytoplankton dispersed from the sea ice to the ice edge and even into open waters. Thus, these phytoplankton in the sea ice may serve as a "seed bank" for phytoplankton population succession in the subarctic ecosystem. Moreover, historical studies combined with these results suggest that the sizes of diatom species have become smaller, shifting from microplankton to nannoplankton-dominated communities.

  6. Tortuosity of the Antarctic Sea Ice over the Weddell Sea

    NASA Astrophysics Data System (ADS)

    Beard, J.; Heinrichs, J. F.

    2011-12-01

    The objective of the research was to mathematically characterize the edge of the Antarctic sea ice in the Weddell Sea. Because the sea ice may reflect processes involved in the atmosphere and ocean near the ice edge, it may suggest broader changes on the ice. The chosen method was to compare the tortuosity of the edge over time and across seasons. Because the sea ice may reflect processes involved in the atmosphere and ocean near the ice edge, it may suggest broader changes on the ice. Throughout the research, the shapefiles for the Antarctic sea ice were collected from the National Snow and Ice Data Center website and the coordinates were extracted using an add-in for the MapWindow GIS. These points were then put into Excel separated by year and then the distance factor (an approximation to the tortuosity) was calculated and compared by month over time. Preliminary data has shown that the closer to the winter months, the higher the tortuosity. Statistical analysis has shown that there is no clear relationship between tortuosity and the area of the sea ice, and the tortuosity exhibits a weak negative trend over the past 32 years.

  7. Doppler characteristics of sea clutter.

    SciTech Connect

    Raynal, Ann Marie; Doerry, Armin Walter

    2010-06-01

    Doppler radars can distinguish targets from clutter if the target's velocity along the radar line of sight is beyond that of the clutter. Some targets of interest may have a Doppler shift similar to that of clutter. The nature of sea clutter is different in the clutter and exo-clutter regions. This behavior requires special consideration regarding where a radar can expect to find sea-clutter returns in Doppler space and what detection algorithms are most appropriate to help mitigate false alarms and increase probability of detection of a target. This paper studies the existing state-of-the-art in the understanding of Doppler characteristics of sea clutter and scattering from the ocean to better understand the design and performance choices of a radar in differentiating targets from clutter under prevailing sea conditions.

  8. A Can of Sea Worms

    ERIC Educational Resources Information Center

    Zinn, Donald J.

    1977-01-01

    A comprehensive discussion of the free-living worms that inhabit the beaches and subtidal bottoms of the Cape Cod shoreline is presented. Methods for the location, collection, preservation, and identification of sea worms are identified. (BT)

  9. Remigial molt of sea ducks

    USGS Publications Warehouse

    Petersen, Margaret R.; Savard, Jean-Pierre L.

    2015-01-01

    Molt is a dynamic process occurring throughout much of the year in waterfowl. The molt of flight feathers by waterfowl, especially sea ducks, however, occurs over a compressed period of time and in spcific areas used each year. We provide an overview of the flight feather molt of sea ducks. We focus on the need to molt and why, the timing and duration of flight feather mot, and the duration birds remain at molting areas; energetics of molt and strategies for managing energetic needs; molt migration' food resources and foraging behavior; predation risks; temporal constraints and competition; response to disturbance; and molt habitats and seasonal differences in habitat used by sea ducks. We conclude by presenting and discussing data gaps and emphasize the continuing need for a holistic approach to sea duck management and international cooperation among countries.

  10. Zooplankton data: Vertical distributions of zooplankton in the Norweigian and Greenland Seas during summer, 1989

    SciTech Connect

    Lane, P.V.Z.; Smith, S.L.; Schwarting, E.M.

    1993-08-01

    Recent studies of zooplankton populations in the Greenland Sea have focused on processes at the Marginal Ice Zone (MIZ) and the areas immediately adjacent to it under the ice and in open water. These studies have shown a relatively short period of intense secondary productivity which is closely linked temporally and spatially to phytoplankton blooms occurring near the ice edge in spring and early summer. During the summer of 1989 we participated in a project focusing on benthic and water column processes in the basins of the Norwegian and Greenland Seas. This study allowed us to compare biological processes at the MIZ with those occurring in the open waters of the Greenland Sea, and to compare processes at both of these locations with those in the Norwegian Sea. The data presented in this report are the results of zooplankton net tows covering the upper 1000 meters of the water column over the Norwegian Sea basin and the Greenland Sea basin, and the upper 500 meters of open water adjacent to the MIZ in the Greenland Sea. Sampling was conducted between 12 and 29 July 1989.

  11. 50 CFR 648.11 - At-sea sea sampler/observer coverage.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... Atlantic deep-sea red crab; or a moratorium permit for summer flounder; to carry a NMFS-certified fisheries... Atlantic deep-sea red crab permit, a skate permit, or a tilefish permit, if requested by the sea sampler... flounder, scup, black sea bass, bluefish, spiny dogfish, Atlantic herring, Atlantic deep-sea red...

  12. An empirically derived inorganic sea spray source function incorporating sea surface temperature

    NASA Astrophysics Data System (ADS)

    Salter, M. E.; Zieger, P.; Acosta Navarro, J. C.; Grythe, H.; Kirkevåg, A.; Rosati, B.; Riipinen, I.; Nilsson, E. D.

    2015-10-01

    We have developed an inorganic sea spray source function that is based upon state-of-the-art measurements of sea spray aerosol production using a temperature-controlled plunging jet sea spray aerosol chamber. The size-resolved particle production was measured between 0.01 and 10 μm dry diameter. Particle production decreased non-linearly with increasing seawater temperature (between -1 and 30 °C) similar to previous findings. In addition, we observed that the particle effective radius, as well as the particle surface, particle volume and particle mass, increased with increasing seawater temperature due to increased production of particles with dry diameters greater than 1 μm. By combining these measurements with the volume of air entrained by the plunging jet we have determined the size-resolved particle flux as a function of air entrainment. Through the use of existing parameterisations of air entrainment as a function of wind speed, we were subsequently able to scale our laboratory measurements of particle production to wind speed. By scaling in this way we avoid some of the difficulties associated with defining the "white area" of the laboratory whitecap - a contentious issue when relating laboratory measurements of particle production to oceanic whitecaps using the more frequently applied whitecap method. The here-derived inorganic sea spray source function was implemented in a Lagrangian particle dispersion model (FLEXPART - FLEXible PARTicle dispersion model). An estimated annual global flux of inorganic sea spray aerosol of 5.9 ± 0.2 Pg yr-1 was derived that is close to the median of estimates from the same model using a wide range of existing sea spray source functions. When using the source function derived here, the model also showed good skill in predicting measurements of Na+ concentration at a number of field sites further underlining the validity of our source function. In a final step, the sensitivity of a large-scale model (NorESM - the Norwegian Earth System Model) to our new source function was tested. Compared to the previously implemented parameterisation, a clear decrease of sea spray aerosol number flux and increase in aerosol residence time was observed, especially over the Southern Ocean. At the same time an increase in aerosol optical depth due to an increase in the number of particles with optically relevant sizes was found. That there were noticeable regional differences may have important implications for aerosol optical properties and number concentrations, subsequently also affecting the indirect radiative forcing by non-sea spray anthropogenic aerosols.

  13. North Sea platforms revamped

    SciTech Connect

    O'Hare, J.

    1999-12-01

    Many of the early North Sea platforms are reaching their end-of-field life. Most are still equipped with their original drilling package. In a few cases the package has either been removed or decommissioned. The early installations were designed for much simpler and less demanding wells than the horizontal, extended-reach or designer wells common today. Extended-reach wells now can be drilled realistically from ageing platforms, without incurring massive capital expenditure. This can be achieved using the existing drilling package to the limit of its capabilities and supplementing where necessary with relatively minor upgrades or the use of temporary equipment. Drilling even a few more wells from existing platforms not only prolongs field life, it enables any surplus processing capacity to be made available to develop near-field potential with extended-reach drilling (ERD) or by tying back subsea satellite wells, or for processing third-party fluids. The paper describes well design, surface equipment, mud pumps, shakers and solids control equipment, drill cuttings disposal systems, derrick and hoisting system, top drive and drillstring, downhole equipment, well planning, casing wear, logistics, rig preparations, and ERD vs. subsea tie-backs.

  14. A Sea of Lava

    NASA Technical Reports Server (NTRS)

    2003-01-01

    [figure removed for brevity, see original site]

    Islands of older high-standing terrain rise above a sea of relatively young, platy lava flows between two of the largest volcanoes in the solar system.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

    Image information: VIS instrument. Latitude 10.6, Longitude 158.5 East (201.5 West). 19 meter/pixel resolution.

  15. Applied Sea Ice Research

    NASA Astrophysics Data System (ADS)

    Løset, S.

    2009-04-01

    In the late 1960s oil and gas development became an issue in the northern coastal areas of Alaska and Canada. More lately this has also become an issue in the Euroasian Arctic with the Barents and Kara Seas as example on where offshore hydrocarbon production now is being planned. In such waters the key questions prior to a development are related to water depths at the site and in case of ice, how frequent and what type of ice features will be met. Especially the ice conditions and knowledge about them are very decisive for the field development solutions to be chosen. The paper will highlight examples on development solutions where the ice conditions have played a paramount role in the field development plans. An example is the consequences of iceberg threaten in an area and the effect sudden changes in ice drift directions may have on the exploration and drilling solutions chosen. The paper will also discuss how to derive design ice actions values for such waters including scaling from nature to model ice basins.

  16. Exploring the deeper seas

    SciTech Connect

    Witt, R.R., Jr.

    1980-06-05

    The history, current status, and economics of offshore exploration for crude oil and natural gas in water depths over 600 ft since it became a reality in 1965 are reviewed. Development has not progressed as originally anticipated, and only three deepwater areas - the Gulf of Mexico, California, and the North Sea - account for 54% of all wells drilled but have less than 10% of the world's prospective deepwater acreage. Deepwater drilling has barely begun - only one deepwater well has been drilled per 17 million prospective deepwater acres. To date expenditures for deepwater drilling have been uneconomical; however, the tension leg platform is seen as possibly an economical means of producing hydrocarbons from deepwater areas. The enormous front-end expenditure has greatly limited the development of deepwater production. Only the largest oil companies can enter into the risky and very capital-intensive ventures, and even the largest companies can only afford to develop the largest fields which offer the best potential for return of capital. Increased oil prices and stable or good economic conditions of the major industralized nations will probably impact the volume of petroleum consumed in such a way as to render development of deepwater areas economical in the future. (BLM)

  17. Arctic Sea Ice Model Sensitivities

    NASA Astrophysics Data System (ADS)

    Peterson, K. J.; Bochev, P.; Paskaleva, B.

    2010-12-01

    Arctic sea ice is an important component of the global climate system and, due to feedback effects, the Arctic ice cover is changing rapidly. Predictive mathematical models are of paramount importance for accurate estimates of the future ice trajectory. However, the sea ice components of Global Climate Models (GCMs) vary significantly in their prediction of the future state of Arctic sea ice and have generally underestimated the rate of decline in minimum sea ice extent seen over the past thirty years. One of the contributing factors to this variability is the sensitivity of the sea ice state to internal model parameters. A new sea ice model that holds some promise for improving sea ice predictions incorporates an anisotropic elastic-decohesive rheology and dynamics solved using the material-point method (MPM), which combines Lagrangian particles for advection with a background grid for gradient computations. We evaluate the variability of this MPM sea ice code and compare it with the Los Alamos National Laboratory CICE code for a single year simulation of the Arctic basin using consistent ocean and atmospheric forcing. Sensitivities of ice volume, ice area, ice extent, root mean square (RMS) ice speed, central Arctic ice thickness,and central Arctic ice speed with respect to ten different dynamic and thermodynamic parameters are evaluated both individually and in combination using the Design Analysis Kit for Optimization and Terascale Applications (DAKOTA). We find similar responses for the two codes and some interesting seasonal variability in the strength of the parameters on the solution. Sandia National Laboratories is a multi-program laboratory operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U. S. Department of Energy’s National Nuclear Security Administration under Contract DE-AC04-94-AL85000.

  18. Bioactive molecules from sea hares.

    PubMed

    Kamiya, H; Sakai, R; Jimbo, M

    2006-01-01

    Sea hares, belonging to the order Opisthobranchia, subclass Gastropoda, are mollusks that have attracted many researchers who are interested in the chemical defense mechanisms of these soft and "shell-less" snails. Numbers of small molecules of dietary origin have been isolated from sea hares and some have ecologically relevant activities, such as fish deterrent activity or toxicity. Recently, however, greater attention has been paid to biomedically interesting sea hare isolates such as dolastatins, a series of antitumor peptide/macrolides isolated from Dolabella auricularia. Another series of bioactive peptide/macrolides, as represented by aplyronines, have been isolated from sea hares in Japanese waters. Although earlier studies indicated the potent antitumor activity of aplyronines, their clinical development has never been conducted because of the minute amount of compound available from the natural source. Recent synthetic studies, however, have made it possible to prepare these compounds and analogs for a structure-activity relationship study, and started to uncover their unique action mechanism towards their putative targets, microfilaments. Here, recent findings of small antitumor molecules isolated from Japanese sea hares are reviewed. Sea hares are also known to produce cytotoxic and antimicrobial proteins. In contrast to the small molecules of dietary origin, proteins are the genetic products of sea hares and they are likely to have some primary physiological functions in addition to ecological roles in the sea hare. Based on the biochemical properties and phylogenetic analysis of these proteins, we propose that they belong to one family of molecule, the "Aplysianin A family," although their molecular weights are apparently divided into two groups. Interestingly, the active principles in Aplysia species and Dolabella auricularia were shown to be L-amino acid oxidase (LAAO), a flavin enzyme that oxidizes an alpha-amino group of the substrate with molecular oxygen and liberates hydrogen peroxide, with a sequence similar to other known LAAOs, including snake venom. Possible antibacterial activity and cytotoxic activity mechanisms of these proteins are also discussed. PMID:17153345

  19. Sea Level Rise in Tuvalu

    NASA Astrophysics Data System (ADS)

    Lin, C. C.; Ho, C. R.; Cheng, Y. H.

    2012-04-01

    Most people, especially for Pacific Islanders, are aware of the sea level change which may caused by many factors, but no of them has deeper sensation of flooding than Tuvaluan. Tuvalu, a coral country, consists of nine low-lying islands in the central Pacific between the latitudes of 5 and 10 degrees south, has the average elevation of 2 meters (South Pacific Sea Level and Climate Monitoring Project, SPSLCMP report, 2006) up to sea level. Meanwhile, the maximum sea level recorded was 3.44m on February 28th 2006 that damaged Tuvaluan's property badly. Local people called the flooding water oozes up out of the ground "King Tide", that happened almost once or twice a year, which destroyed the plant, polluted their fresh water, and forced them to colonize to some other countries. The predictable but uncontrollable king tide had been observed for a long time by SPSLCMP, but some of the uncertainties which intensify the sea level rise need to be analyzed furthermore. In this study, a span of 18 years of tide gauge data accessed from Sea Level Fine Resolution Acoustic Measuring Equipment (SEAFRAME) are compared with the satellite altimeter data accessed from Archiving Validation and Interpretation of Satellite Data in Oceanography (AVISO). All above are processed under the limitation of same time and spatial range. The outcome revealed a 9.26cm difference between both. After the tide gauge data shifted to the same base as altimeter data, the results showed the unknown residuals are always positive under the circumstances of the sea level rise above 3.2m. Apart from uncertainties in observing, the residual reflected unknown contributions. Among the total case number of sea level rise above 3.2m is 23 times, 22 of which were recorded with oceanic warm eddy happened simultaneously. The unknown residual seems precisely matched with oceanic warm eddies and illustrates a clear future approach for Tuvaluan to care for.

  20. Modern processes controlling the sea bed sediment formation in Barents Sea

    NASA Astrophysics Data System (ADS)

    Balanyuk, I.; Dmitrievsky, A.; Shapovalov, S.; Chaikina, O.; Akivis, T.

    2009-04-01

    The Barents Sea is one of the key regions for understanding of the postglacial history of the climate and circulation of the World Ocean. There are the limits of warm North Atlantic waters penetration to the Arctic and a zone of interaction between Atlantic and Arctic waters. The Barents Se's limits are the deep Norwegian Sea in the West, the Spitsbergen Island and the Franz Josef Land and the deep Nansen trough in the North, the Novaya Zemlya archipelago in the East and the North shore of Europe in the South. An analysis of Eurasian-Arctic continental margin shows correspondence between the rift systems of the shelf with those of the ocean. This relation can be observed in the central Arctic region. All the rift systems underlying the sediment basin are expressed in the sea bed relief as spacious and extensive graben valleys burnished by lobes. Two transverse trenches cross both shelf and continental slope, namely the Medvezhinsky trench between Norway and Spitsbergen in the West and the Franz Victoria trench between Spitsbergen and the Franz Josef Land in the North. The Barents and the Kara Seas are connected by the Kara Gate Strait and wide transverse trough of Saint Anna in the North-West. The recent assessment of the eolian solid sediment supply to the Barents Sea is about 0.904 tons. The Barents Sea as a whole should be considered as "starving" in terms of its feeding with solid sediment matter. Observations show the considerable part of the sea bottom to be free of Holocene sediment cover. The more ancient Quaternary units or bedrock can be seen at the bottom surface. This phenomenon is the most typical for arches of relatively shallow elevations. Thick accumulations of new sediments are connected with fjords. The amount of sea ice delivered from the Barents Sea to the Arctic Ocean is 35 km3 a year. This value should be added by iceberg delivery from the North island of Novaya Zemlya, the Franz Josef Land, the Spitsbergen Island and North Norway but most of terrigenous matter settles in natural sediment traps of fjords. The Barents Sea bottom has rather dissected relief. A number of isometric or, rarer, elongated underwater elevations (Perseus, Central, the Admiralty Bar, the Goose shoal) and separation trenches and troughs (South and North Barents Sea troughs, Perseus, Aldanov, Medvezhinsky, Franz Victoria, West and South Novozemelsky trenches) can be distinguished. The major processes that control a structure of the friable sedimentary cover of Arctic shelves appear on the seismic acoustic records as chaotic effect of cryolithogenesis (permafrost, themokarst, thawed patches, paleoriverbeds, etc.) and hydrocarbons migration (gas hydrates, gas saturated sediments, gas seeping, porkmarks, etc). Such phenomena are the main components of geo-risks for oil and gas fields development in Arctic Seas and are, together with the gas hydrates deposits, the top priority objects of seismic acoustic measurements. The shelf of the Barents Sea is one of the most extensively studied with high resolution acoustic methods because of large-scale engineering and geological problems solved in process of its industrial development. Mainly, it is related to exploring and development of oil and gas fields, oil terminals and submarine pipelines construction, and building up the whole infrastructure for their exploitation.

  1. DESERVE - Dead Sea Research Venue

    NASA Astrophysics Data System (ADS)

    Mohsen, A.; Weber, M. H.; Kottmeier, C.

    2013-12-01

    DESERVE 'Dead Sea Research Venue' focuses on the Dead Sea region as it is a unique environment and may be considered as one of the most inspiring natural laboratories on Earth. The Dead Sea Region is an exceptional ecosystem whose seismic activity has influenced all facets of the development, from ground water availability to human evolution. DESERVE addresses three grand challenges: Environmental Risks, Water Availability, Climate Change and comprises long term monitoring of geophysical parameters, studies of coupled processes in the atmosphere, hydrosphere and lithosphere as well as modeling of prediction and remediation strategies of geogenic risks. The Dead Sea has been selected for this integrated approach because it constitutes an outstanding 'natural laboratory' to study these phenomena, as - all 3 challenges are critical in this region. - the region is especially sensitive to climate change and human influences such as ground and surface water over-exploitation for agriculture and industrial purposes. - environmental processes are subject to boundary conditions that cannot be found elsewhere on Earth - understanding their interactions and the future evolution of the whole Dead Sea region are of key importance for economic development in peaceful cooperation. Results obtained in the Dead Sea region are also of prototype relevance for other (semi)-arid terminal basins of the world.

  2. Variability patterns of the general circulation and sea water temperature in the North Sea

    NASA Astrophysics Data System (ADS)

    Mathis, M.; Elizalde, A.; Mikolajewicz, U.; Pohlmann, T.

    2015-06-01

    This study investigates patterns of spatio-temporal variability in the North Sea and their major driving mechanisms. Leading variability modes of the general circulation and sea water temperature are extracted from model results by means of Empirical Orthogonal Functions (EOF) analysis. The model results originate from an uncoupled simulation with the global ocean model MPIOM, forced with ERA40 reanalysis data at the air-sea interface. For this regional model study, MPIOM has been run with a stretched grid configuration enabling higher horizontal resolution in the Northwest European Shelf and North Atlantic ocean. The analysis is applied to interannual variabilities of winter and summer separately. The results indicate that on seasonal scales the leading variability mode of the general circulation affects the entire North Sea, accompanied by significant inflow anomalies through the Fair-Isle Passage. Correlations of the corresponding Principal Component (PC) with wind density functions reveal the circulation anomalies to coincide with westerly and south-westerly wind anomalies. The second mode describes circulation anomalies along the Norwegian Trench and English Channel, which correlate with north-westerly wind anomalies caused by variations in large-scale atmospheric pressure areas centered over the British Isles. For sea water temperature, distinct variability patterns are induced by variable surface heat fluxes, vertical mixing, and variable advective heat fluxes. The first mode of both the general circulation and water temperature in winter mainly represents the response to atmospheric variations in the North Atlantic Oscillation (NAO). However, the higher modes account for such variabilities that cannot be explained by the NAO. As a consequence of the integrated effects of the different variability modes on the circulation system and heat content, local correlations of the NAO with volume transports and water temperature are weakened in the regions of Atlantic inflow.

  3. Total and organic mercury in Barents sea pelagic fish

    SciTech Connect

    Joiris, C.R.; Ali, I.B.; Hoisbeek, L. Bossicart, M.; Tapia, G.

    1995-11-01

    One of the main questions, when studying mercury levels in natural samples, is to define how far the measured concentrations correspond to natural- or background-levels or to actual contamination due to human activities. To establish background pristine levels of Hg in the marine environment, areas of very low human activities are often proposed. Arctic and Antarctic waters, together with deep oceans waters, are best suited and provide themselves for such studies. Barents Sea areas were used in this study, even if the existence of an important atmospheric transport of Hg probably caused an increase of Hg levels at a global scale. Instead of analyzing mercury from the very low concentrations in sea water, it is much easier to identify it from the higher concentrations which organisms, used as bioindicators, have built up in their tissues. By using these bioindicators to study the bioavailable fraction of the stable residues, one also integrates small scale temporal and spatial variations. Pelagic fish were used in this work to study the ecotoxicology of Hg in the Barents Sea. This study has been made possible due to recent access of the Barents Sea to western scientists and it is to serve as a complement to existing studies by the same team in the Greenland and Norwegian seas, and the southwestern part of the Barents Sea. 19 refs., 4 figs., 2 tabs.

  4. Mesoscale structures in the Subarctic Seas - observations and modelling

    NASA Astrophysics Data System (ADS)

    Walczowski, W.; Maslowski, W.

    2003-04-01

    Scientists from IO PAS have investigated the sub-arctic seas since 1989. In this study we present data collected by the IO PAS in contribution to VEINS project as well as from the other cruises conducted by R.V. Oceania in the Barents, Norwegian and Greenland seas. Observed mesoscale structures will be compared with results from two high-resolution models of the Pan-Arctic region forced with realistic atmospheric fields. The first model is configured at 1/6°(~18 km) and 30-layer grid and the second at 1/12° (~9 km) and 45-layer grid. Both models are developed at the Naval Postgraduate School, Monterey. Based on in situ measurements and model output, we specify regions of high mesoscale activity, which exist mainly along the Barents slope, in the area west of Spitsbergen and along the Arctic Front, separating water of Atlantic origin from the Greenland Sea Gyre. A comparison between current patterns, total kinetic energy (TKE) and eddy kinetic energy (EKE) calculated from the models and from in situ data will be presented. We will analyse observed mesoscale structures including frontal meanders and intrusions, cyclonic and anticyclonic eddies, and dense water plumes. Selected phenomena will be compared with modelled structures. Investigations of the Arctic Front show that mesoscale eddies and intrusions play an important role in the cross-frontal volume, salt and heat exchanges. Anticyclonic eddies originating from the frontal meanders carry considerable volume of Atlantic Water into the Greenland Sea. The transport of Atlantic Water from the Norwegian Sea into the Greenland Sea Gyre will be analysed based on field data and eddy-permitting model output. Anticyclonic eddies originating to the west of Spitsbergen play an important role in the recirculation of Atlantic Water in Fram Strait. Observed and modelled processes and pathways of the recirculation of Atlantic Water will be presented.

  5. Aral Sea and sustainable development.

    PubMed

    Usmanova, R M

    2003-01-01

    Until 1960 the Aral Sea was considered the 4th largest lake in the world by surface area. The Aral Sea has two main inflows--the Amudarya and Syrdarya rivers with about 30 tributaries. From early 1960s because of extensive water use--unreturned withdrawal of water for irrigation and consequent drying up of many tributaries before reaching the main rivers--the water level in the Aral Sea began falling very rapidly. In 1965 the Aral Sea received about 56 cubic km of fresh water yearly, but this number fell to zero by the early 1980s. By 1990 the level of the Aral Sea water fell by more than 17 m, the volume of water decreased by 75%, the salinity of seawater increased up to 30 g/l, and the surface area of the sea reduced from 66,400 sq. km to 31,500 sq. km. The ecological situation in Aral Sea zone has became very dramatic. It has led to the changing of climate in the region, irrigated soils becoming deserts, deterioration of underground and surface water quality, reducing of available water for domestic and agricultural needs, loss of Aral Sea fishing and transportation importance, numerous other problems and finally put the health of present and future generations under threat. This situation not only does not promote further development of the economy of the region, but has also caused damage with irreparable negative consequences. The fact is that the basis of the regional economy is fishing and other associated businesses. Since Uzbekistan is most agricultural country its economy has serious complications. In order to prevent further deepening of this catastrophe and to improve the present situation in this area the Government of the Republic of Uzbekistan has developed a series of measures: in particular it developed efficient water use schemes, changing the cotton situation (that during the Soviet period was grown as monoculture) by planting less water-consuming varieties, reviewing using of fertilizers in agriculture etc. The Aral Sea drought became an international disaster. World Bank, UNESCO, BMBF and others attacked the problem to protect the Aral Sea. PMID:12793660

  6. Past and present Aral Sea

    NASA Astrophysics Data System (ADS)

    Dukhovniy, Viktor; Stulina, Galina; Eshchanov, Odylbek

    2013-04-01

    The tragedy of disappearing of Aral Sea is well known to the World. Before and after collapse of Soviet Union, a huge quantity of scientific and popular editions described with grief the situation around the Aral Sea. After the NIS states became independent, World Bank, UNDP, UNEP in proper competition with each other had provided some assessment of the situation through presentation of some small and medium grants, but after 2000, the local population remained alone with own problems. Although on the eyes of the present generation a unique transformation of great water body into deserts took place, the global scientific community did not find forces and financing for real and detail investigation of the processes accompanying the Sea shrinking and land formation. We should acknowledge and give big respect to NATO, later to German Government that through GTZ (now GIZ) - German International Collaboration Agency - and GFZ (Potzdam) paid attention to this area of environment crisis and organized scientific and protective design in the so-called Priaralie - the territory around the drying Sea and delta of the two rivers - Amudarya and Syrdarya. Thank to this assistance, the local specialists in collaboration with limited a number of foreign scientists (N.Aladin, P.Zavialov, Joop de Schutter, Hans Wilps, Hedi Oberhansli) organized significant works for detail socioeconomic, ecological and hydrological assessment situation in Priaralie and on the Aral sea coast. On this base, Ministry of Agriculture and Water resources of Uzbekistan and State Committee of Water resources of Kazakhstan developed a plan of rehabilitation of Amudarya and Syrdarya deltas and started implementation of these projects. If Kazakh water authority moved ahead in wetland restoration faster, a forestation of delta and drying bed of Aral Sea got big success in Uzbek territory. 244 thousands hectares of saxsaul and tamarix were planted for protection of the Priaralie. By request of GTZ SIC, ICWC organized in 2005-2009 sixth expeditions for complex remote sensing and ground investigations Aral Sea former bottom that were complemented in 2010 -2011 by two expeditions with GFZ. As a result, the landscape, soils and environment mapping was done with determination of ecologically unstable zones and assessment total change of lands situation compared with the pre-independence time. Moreover - methodic of monitoring water, environment and hydro geological indicators on the all deltas area was elaborated, organized its testing and combined with remote sensing data on Amudarya delta for 2009-2012. It permits to SIC ICWC to organize systematic permanent (decadal) monitoring and recording of size, volume and level of water in Aral Sea. Since the beginning of regular observations over the Aral Sea level, 2 periods can be emphasized: 1. Conditionally natural period - 1911-1960 - characterized by a relatively stable hydrological regime, with fluctuations in the level around 53 m and the range of inter-annual fluctuations at no more than 1 m., when the sea received annually about a half of the run-off in the Syrdarya and Amudarya Rivers, i.e. 50-60 km3/yr. 2. Intensive anthropogenic impact period - since the 1960s, a vast extension of irrigable land was carried out in Central Asia that resulted in intensive diversion of river run-off. Since then, the sea level has been falling steadily, causing a dramatic reduction in the water surface area, a decrease in water volume and depths, great changes in shoreline configuration and an expansion of the desert areas adjacent to the Aral Sea. From 1960-1985, when the sea was an integral water body, slight lowering in the sea level took place until the 1970s, when the sea-level decreased with the mean level lowering 1 m. The desiccation process accelerated visibly from the mid 1970s. In 1975-1980, the level decreased by 0.65 m a year on average. Moreover, the level dropped greatly, when the run-off of the Amudarya did not reach the Aral Sea any more (1980-1990). Kokaral was the first of the large islands becoming a peninsula, separating the Small Aral Sea in the north-east by joining the shoreline in the west. By 1986, the peninsula practically detached the small Aral Sea from the large Aral Sea, leaving only a narrow flow passage in the east. Since that time, the hydrological regimes of the Small and Large Seas have become separated. The construction of Kokaral dam in Kazakhstan, 12 km long and 8 m high, then completely separated the small Aral Sea from the large Aral Sea and changed the hydrological regimes of the water bodies. Level of this part of Sea became from this moment permanently higher than in the large Aral Sea on 42 m a.s.l. The eastern part of the sea, where the bed is much shallower and the slope is gentler is more subjected to shrinking then the western part. 2005 year became threshold, from which Eastern Aral Sea began new story - deviation from almost empty water body to almost 4 meters depth. Present assessment of water balance of Aral Sea and delta at whole dependent from delivery water river and drainage flow through control section of Samanbay on the Amudarya and some cross sections on the enter main collectors to the delta boundary. These hydrological characteristics accepted on the base of information from BWO Amudarya and our monitoring of allocation of different waters on the delta. Water volume and water surface area of Eastern and Western Aral Sea bowls were definite on the result RS data from Landsat. Bathymetric curves gave ability to assess dynamic levels of Seas. After series of enough water years 2002 - 2005 with average water income to south Priaralie 12.5 km3 period of water scarce years lead to sharp decrease of surface water area of the Eastern bowl from 1010,5 th.ha on average on two time with failure of level from 31,1 m up to average 28,5 m. But phase of permanent reducing all indicators water body changed in 2008 on deviation in range from 26.3 m to 29.5 m. Some time sharp changes in the level of water in 2.0 m take place in time one year. These changes same as degree of deltas' watering depends fully from inflow water to boundary of deltas. At the same time, the Western bowl remained more or less stable and without direct flow of surface water supported own water stability based on balance between evaporation and precipitation plus presumably the inflow of deep ground water.

  7. Variability of the Atlantic inflow to the Nordic Seas and its causes inferred from observations of sea surface height

    NASA Astrophysics Data System (ADS)

    Richter, K.; Segtnan, O. H.; Furevik, T.

    2012-04-01

    We investigate the potential to use sea surface height observed with satellites and tide gauges to explore and to estimate the variability of volume transport of Atlantic water to the Nordic Seas. It is shown that the variability of the Atlantic inflow to the Nordic Seas over the Iceland Faroe Ridge (Faroe Current) primarily responds to an oceanic regime dominated by steric height changes in the interior Nordic Seas. In contrast, variations in the Norwegian Atlantic Slope Current measured at the Svinøy section are largely driven by direct wind forcing. Using linear regression analysis, volume transports anomalies were successfully modeled from the leading modes of altimeter-derived sea surface height and reconstructed back in time using sea surface height observations from tide gauges. The reconstructions explain 22% and 38% of the observed variability in the Faroe and Svinøy currents, respectively. For the Svinøy Current, the reconstruction indicates that the volume transport variability is typically of the order ± 1 Sv. High inflow around 1983 and low inflow around 1987 coincide with times when respectively warm and cold anomalies passed through the system.

  8. Seismic investigations in the Weddell Sea Embayment

    NASA Astrophysics Data System (ADS)

    Haugland, Kristen; Kristoffersen, Yngve; Velde, Anders

    1985-04-01

    Seismic multi-channel data collected during Norwegian Antarctic Research Expeditions in 1976-1977 and 1978-1979 outline aspects of the Cenozoic depositional environment in the Weddell Sea Embayment. Acoustic basement, probably representing the East Antarctic craton, is exposed in a 50-100 km wide swath along the ice barrier between 78°S-75.5°S on the eastern side of the Crary Trough. The shelf prograded westward and northward from the craton into a subsiding basin colinear with the Transantarctic Mountain Range. Measured sediment thicknesses exceed 5 km. During middle and late Tertiary times a submarine fan complex—the Crary Fan—developed on the southeastern margin of the Weddell Sea Embayment. The glacially eroded Crary Trough is located at the contact between the craton and a sedimentary basin to the west. The entire sedimentary section is undisturbed by faulting or folding, which indicates that any movements related to Cenozoic uplift of the Trans-Antarctic Mountains and/or relative motion of East Antarctica had little effect in the area north of the Filchner Ice Shelf east of 41°W.

  9. SeaWinds - Greenland

    NASA Technical Reports Server (NTRS)

    1999-01-01

    The frequent coverage provided by NASA's SeaWinds instrument on the QuikScat satellite provides unprecedented capability to monitor daily and seasonal changes in the key melt zones of Greenland, which is covered with a thick ice sheet that resulted from snow accumulating over tens of thousands of years. The thickness of the snow layers reveals details about the past global climate, and comparing snow accumulation and snow melting can provide insight into climate change and global warming. In particular, the extent of summer melting of snow in Greenland is considered a sensitive indicator of global change.

    Earlier scatterometer data has suggested that Greenland has experienced significantly more melting in recent years. This figure compares the melting observed over 15 days during July 1999 in Greenland. The red areas around the central blue and white areas are the main melt zones and have lower radar back scatter because of water on the surface that saturates the surface snow. As the days warm up, the melt extent dramatically increases. Comparing this data with computer models and past scatterometer data will help scientists evaluate the inter-annual variability of the melting as a step toward understanding potential climate change.

    The world's large ice sheets in Greenland and Antarctica act as vast storehouses of freshwater. Summer season melting releases large quantities of freshwater into the ocean, and year-to-year variations can have a significant impact on global sea level. Furthermore, long-term changes in the patterns and extent of melting on the large ice sheets reflect the effects of climate variability; thus Greenland is considered a sensitive indicator of global warming.

    Satellite microwave radars are extremely sensitive to melting and can provide the only effective means of accurately measuring the year-round picture of the extent and variability in ice sheet melting. Daily mean images were produced from QuikScat data collected over the Greenland ice sheet at the height of the present summer melt period. In the top row, four images are shown at intervals of 5 days, for (a) day 203, (b) 208,(c) 213, and (d) 218 in 1999. Blue and white colors indicate surfaces which are cold and dry, while read and black indicate wet snow surfaces experiencing melting. The coastal regions are lower in elevation and begin to melt first. As summer progresses, the area of melting expands inland and northwards along the western coast of Greenland as air temperatures warm. A large pale and dark blue region in the central, high-elevation part of the ice sheet survives each summer without experiencing any melting. This is known as the dry snow region, and its area is a measure of the stability of the central part of the ice sheet. The line dividing the melt area and the dry snow is very sensitive to climate conditions and monitoring this line will help scientists determine whether the Earth's climate is changing.

    The lower series of four images shows the daily variability in the radar data within each image. White patches in these images identify regions where the most rapid changes are taking place. Air temperature and precipitation variations are responsible for the patterns, with the greatest impact over the southern tip of Greenland occurring from storms originating over the Atlantic. Note that the red areas of central and northern Greenland experience much smaller or slower changes, with the central ice sheet showing little change during this summer period.

    With its frequent coverage, the SeaWinds instrument is a power and unique tool for monitoring the health of the large ice sheets. The continuing time-series of data is a valuable contribution to assessments of the effects and impact of global change in the polar regions.

    NASA's Earth Science Enterprise is a long-term research and technology program designed to examine Earth's land, oceans, atmosphere, ice and life as a total integrated system. JPL is a division of the California Institute of Technology, Pasadena, CA.

  10. Air-sea interactions in sea surface temperature frontal region

    NASA Astrophysics Data System (ADS)

    Pianezze, Joris; Redelsperger, Jean-Luc; Ardhuin, Fabrice; Reynaud, Thierry; Marié, Louis; Bouin, Marie-Noelle; Garnier, Valerie

    2015-04-01

    Representation of air-sea exchanges in coastal, regional and global models represent a challenge firstly due to the small scale of acting turbulent processes comparatively to the resolved scales of these models. Beyond this subgrid parameterization issue, a comprehensive understanding of air-sea interactions at the turbulent process scales is still lacking. Many successful efforts are dedicated to measure the energy and mass exchanges between atmosphere and ocean, including the effect of surface waves. In comparison less efforts are brought to understand the interactions between the atmospheric boundary layer and the oceanic mixing layer. In this regard, we are developing research mainly based on ideal and realistic numerical simulations which resolve very small scales (horizontal resolutions from 1 to 100 meters) in using grid nesting technics and coupled ocean-wave-atmosphere models. As a first step, the impact of marked gradients in sea surface temperatures (SST) on air-sea exchanges has been explored through realistic numerical simulations at 100m horizontal resolution. Results from simulations of a case observed during the FROMVAR experiment will be shown. The talk will mainly focus on the marked impact of SST front on the atmospheric boundary layer (stability and winds), the air-sea exchanges and surface parameters (rugosity, drag coefficient) Results will be also shown on the strong impact on the simulated atmosphere of small scale variability of SST field.

  11. Deep-sea Hexactinellida (Porifera) of the Weddell Sea

    NASA Astrophysics Data System (ADS)

    Janussen, Dorte; Tabachnick, Konstantin R.; Tendal, Ole S.

    2004-07-01

    New Hexactinellida from the deep Weddel Sea are described. This moderately diverse hexactinellid fauna includes 14 species belonging to 12 genera, of which five species and one subgenus are new to science: Periphragella antarctica n. sp., Holascus pseudostellatus n. sp., Caulophacus (Caulophacus) discohexactinus n. sp., C. ( Caulodiscus) brandti n. sp., C. ( Oxydiscus) weddelli n. sp., and C. ( Oxydiscus) n. subgen. So far, 20 hexactinellid species have been reported from the deep Weddell Sea, 15 are known from the northern part and 10 only from here, while 10 came from the southern area, and five of these only from there. However, this apparent high "endemism" of Antarctic hexactinellid sponges is most likely the result of severe undersampling of the deep-sea fauna. We find no reason to believe that a division between an oceanic and a more continental group of species exists. The current poor database indicates that a substantial part of the deep hexactinellid fauna of the Weddell Sea is shared with other deep-sea regions, but it does not indicate a special biogeographic relationship with any other ocean.

  12. Sea Ice Concentration and Extent

    NASA Technical Reports Server (NTRS)

    Comiso, Josefino C.

    2014-01-01

    Among the most seasonal and most dynamic parameters on the surface of the Earth is sea ice which at any one time covers about 3-6% of the planet. In the Northern Hemisphere, sea ice grows in extent from about 6 x 10(exp 6) sq km to 16 x 10(exp 6) sq km, while in the Southern Hemisphere, it grows from about 3 x 10(exp 6) sq km to about 19 x 10(exp 6) sq km (Comiso, 2010; Gloersen et al., 1992). Sea ice is up to about 2-3 m thick in the Northern Hemisphere and about 1 m thick in the Southern Hemisphere (Wadhams, 2002), and compared to the average ocean depth of about 3 km, it is a relatively thin, fragile sheet that can break due to waves and winds or melt due to upwelling of warm water. Being constantly advected by winds, waves, and currents, sea ice is very dynamic and usually follows the directions of the many gyres in the polar regions. Despite its vast expanse, the sea ice cover was previously left largely unstudied and it was only in recent years that we have understood its true impact and significance as related to the Earths climate, the oceans, and marine life.

  13. Antarctic Peninsula and Weddell Sea

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Numerous icebergs are breaking out of the sea ice in the Southern Ocean surrounding the Antarctic Peninsula. This true-color MODIS image from November 13, 2001, shows several icebergs drifting out of the Weddell Sea. The Antarctic Peninsula (left) reaches out into the Drake Passage, which separates the southern tip of South America from Antarctica. Warmer temperatures have cleared a tiny patch of bare ground at the Peninsula's tip. The predominant ocean current in the area is the Antarctic Circumpolar Current ('circum' meaning 'around'), which is also the 'West Wind Drift.' The current is the largest permanent current in the world, and water is moved eastward by westerly winds. Icebergs leaving the Weddell Sea are likely to be moved north and east by the current. Credit: Jacques Descloitres, MODIS Land Rapid Response Team, NASA/GSFC

  14. Internal and external forcing of sea level variability in the Black Sea

    NASA Astrophysics Data System (ADS)

    Volkov, Denis L.; Landerer, Felix W.

    2015-11-01

    The variability of sea level in the Black Sea is forced by a combination of internal and external processes of atmospheric, oceanic, and terrestrial origin. We use a combination of satellite altimetry and gravity, tide gauge, river discharge, and atmospheric re-analysis data to provide a comprehensive up-to-date analysis of sea level variability in the Black Sea and to quantify the role of different environmental factors that force the variability. The Black Sea is part of a large-scale climatic system that includes the Mediterranean and the North Atlantic. The seasonal sea level budget shows similar contributions of fresh water fluxes (precipitation, evaporation, and river discharge) and the Black Sea outflow, while the impact of the net surface heat flux is smaller although not negligible. We find that the nonseasonal sea level time series in the Black and Aegean seas are significantly correlated, the latter leading by 1 month. This lag is attributed to the adjustment of sea level in the Black Sea to externally forced changes of sea level in the Aegean Sea and to the impact of river discharge. The nonseasonal sea level budget in the Black Sea is dominated by precipitation and evaporation over the sea itself, but external processes such as river discharge and changes in the outflow can also cause some large synoptic-scale sea level anomalies. Sea level is strongly coupled to terrestrial water storage over the Black Sea drainage basin, which is modulated by the North Atlantic Oscillation (NAO). We show that during the low/high NAO southwesterly/northeasterly winds near the Strait of Gibraltar and southerly/northerly winds over the Aegean Sea are able to dynamically increase/decrease sea level in the Mediterranean and Black seas, respectively.

  15. Sargasso Sea lead levels drop

    NASA Astrophysics Data System (ADS)

    Katzoff, Judith A.

    Concentrations of lead in the Sargasso Sea have decreased since at least 1979, following the phase-out of leaded gasoline in the United States that began in the early 1970s, according to a group of three scientists at the Massachusetts Institute of Technology (MIT). The Sargasso Sea is an area of the western North Atlantic Ocean centered near Bermuda, extending from about 20° to 40°N (from about the latitude of Cuba to about the latitude of North Carolina). This work will be presented on Friday morning, December 12, at the 1986 AGU Fall Meeting/ASLO Winter Meeting in San Francisco (Eos, November 4, 1986, p. 1066).

  16. Global Sea Rise: a Redetermination

    NASA Astrophysics Data System (ADS)

    Douglas, Bruce C.

    It is well established that sea level trends obtained from tide gauge records shorter than about 50-60 years are corrupted by interdecadal sea level variation. However, only a fraction (<25%) of even the long records exhibit globally consistent trends, because of vertical crustal movements. The coherent trends are from tide gauges not at collisional plate boundaries, and not located in or near areas deeply ice-covered during the last glaciation. Douglas (1991), using ICE-3G values for the postglacial (PGR) rebound correction, found 21 usable records (minimum length 60 years, average 76) in 9 oceanographic groups that gave a mean trend for global sea level rise of 1.8 mm/yr ± 0.1 for the period 1880-1980. In that analysis, a significant inconsistency of PGR-corrected U.S. east coast trends was noted, but not resolved. Now, even after eliminating those trends, more (24) long records (minimum 60 years, average 83) are available, including series in the southern hemisphere not previously used. The mean trend of 9 groups made up of the newly-selected records is also 1.8 mm/yr ± 0.1 for global sea level rise over the last 100+ years. A somewhat smaller set of longer records in 8 groups (minimum 70 years, average 91) gives 1.9 mm/yr ± 0.1 for the mean trend. These values are about an order of magnitude larger than the average over the last few millennia. The recent (in historical terms) dramatic increase in the rate of global sea level rise has not been explained, and no acceleration during the last century has been detected. This situation requires additional investigation and confirmation. VLBI/GPS/absolute gravity measurements of crustal motions can be employed to correct many long (60+ years) tide gauge records not now usable because of vertical crustal movements, improving the geographic coverage of sea level trends. Direct altimetric satellite determinations of global sea level rise from satellites such as TOPEX/POSEIDON and its successors can provide an independent estimate in possibly a decade or so, and thereby ascertain whether or not there has been any recent change in the rate of global sea level rise.

  17. Future sea-level rise in the Mediterranean Sea

    NASA Astrophysics Data System (ADS)

    Galassi, Gaia; Spada, Giorgio

    2014-05-01

    Secular sea level variations in the Mediterranean Sea are the result of a number of processes characterized by distinct time scales and spatial patterns. Here we predict the future sea level variations in the Mediterranean Sea to year 2050 combining the contributions from terrestrial ice melt (TIM), glacial isostatic adjustment (GIA), and the ocean response (OR) that includes the thermal expansion and the ocean circulation contributions. The three contributions are characterized by comparable magnitudes but distinctly different sea-level fingerprints across the Mediterranean basin. The TIM component of future sea-level rise is taken from Spada et al. (2013) and it is mainly driven by the melt of small glaciers and ice caps and by the dynamic ice loss from Antarctica. The sea-level fingerprint associated with GIA is studied using two distinct models available from the literature: ICE-5G(VM2) (Peltier, 2004) and the ice model progressively developed at the Research School of Earth Sciences (RSES) of the National Australian University (KL05) (see Fleming and Lambeck, 2004 and references therein). Both the GIA and the TIM sea-level predictions have been obtained with the aid of the SELEN program (Spada and Stocchi, 2007). The spatially-averaged OR component, which includes thermosteric and halosteric sea-level variations, recently obtained using a regional coupled ocean-atmosphere model (Carillo et al., 2012), vary between 2 and 7 cm according to scenarios adopted (EA1B and EA1B2, see Meehl at al., 2007). Since the sea-level variations associated with TIM mainly result from the gravitational interactions between the cryosphere components, the oceans and the solid Earth, and long-wavelength rotational variations, they are characterized by a very smooth global pattern and by a marked zonal symmetry reflecting the dipole geometry of the ice sources. Since the Mediterranean Sea is located in the intermediate far-field of major ice sources, TIM sea-level changes have sub-eustatic values (i.e. they do not exceed the global average) and show little (but still significant) variations across the basin associated with the subsidence driven by the meltwater load. For year 2050, TIM calculations predict a sea-level rise of ~10 and ~30 cm for the mid range and the high end scenarios, respectively. Mainly because of the distinct mantle viscosity profiles adopted in ICE-5G(VM2) and KL05, the GIA patterns differ significantly and, in contrast with the TIM fingerprint, are both characterized by strong variations across the Mediterranean Sea, showing maximum values in the bulk of the basin. For the OR component, a significant geographical variation is observed across the Mediterranean sub-basins, corresponding to different Atlantic boundary conditionsAccording to this study, the total future sea-level rise for year 2050 will reach maximum values for the extreme scenario (hig-hend prediction for TIM, KL05 for GIA and EA1B2 for OR) of ˜ 27 cm in average with peak of ˜ 30 cm in the central sub-basins. Our results show that when these three components of future sea-level rise are simultaneously considered, the spatial variability is enhanced because of the neatly distinct geometry of the three fingerprints. References: Carillo, A., Sannino, G., Artale, V., Ruti, P., Calmanti, S., DellAquila, A., 2012, Clim. Dyn. 39 (9-10), 2167-2184; Fleming, K. and Lambeck, K., 2004, Quat. Sci. Rev. 23 (9-10), 1053-1077; Meehl, G.A., and 11 others, 2007, in Climate Change 2007: The Physical Science Basis, Cambridge University Press; Peltier W.R., 2004, Annu. Rev. Earth Pl. Sc., 32, 111-149; Spada, G. and Stocchi, P., 2007, Comput. and Geosci., 33(4), 538-562; Spada G., Bamber J. L., Hurkmans R. T. W. L., 2013, Geophys. Res. Lett., 1-5, 40.

  18. Orientation and open-sea navigation in sea turtles

    PubMed

    Lohmann; Lohmann

    1996-01-01

    Loggerhead sea turtle hatchlings (Caretta caretta L.) emerge from underground nests, scramble to the sea and begin a transoceanic migration by swimming away from their natal beach and into the open ocean. Evidence suggests that hatchlings sequentially use three different sets of cues to maintain orientation during their initial migration offshore. While on the beach, hatchlings find the ocean by crawling towards the lower, brighter seaward horizon and away from the dark, elevated silhouettes of vegetation and dunes. Upon entering the ocean, turtles initially orient seawards by swimming into waves, which can be detected as orbital movements from under water. Laboratory experiments have demonstrated that turtles can transfer a course initiated on the basis of waves or visual cues to a course mediated by a magnetic compass. Thus, by setting a magnetic course on the basis of nearshore cues that indicate the seaward direction, hatchlings may continue on offshore headings after entering deep water beyond sight of land. Sea turtles may use the earth's magnetic field not only as a cue for compass orientation but also as a source of world-wide positional information. Recent experiments have demonstrated that loggerheads can detect subtle differences in magnetic field inclination and intensity, two geomagnetic features that vary across the surface of the earth. Because most nesting beaches and oceanic regions are marked by a unique combination of these features, these findings raise the possibility that adult sea turtles navigate using a bicoordinate magnetic map. PMID:9317364

  19. Impact of Sea Spray on Air-Sea Fluxes

    NASA Astrophysics Data System (ADS)

    Veron, Fabrice; Mueller, James

    2013-11-01

    The contributions of sea spray drops to the total air-sea exchanges of momentum, heat, and mass remain an open question. A number of factors obscure any simple quantification of their contribution: the number of drops formed at the ocean surface and the per-drop contribution to the fluxes. To estimate these per-droplet fluxes, we present results from a large number of drop trajectories, which are simulated with a recently developed Lagrangian Stochastic model adapted for the heavy drop transport and evaporation within the marine boundary layer. Then, using commonly accepted spray generation functions we present estimates of spray fluxes which account for the mediating feedback effects from the droplets on the atmosphere. The results suggest that common simplifications in previous sea spray models, such as the residence time in the marine boundary layer, may not be appropriate. We further show that the spray fluxes may be especially sensitive to the size distribution of the drops. The total effective air-sea fluxes lead to drag and enthalpy coefficients that increase modestly with wind speed. The rate of increase for the drag coefficient is greatest at moderate wind speeds, while the rate of increase for the enthalpy coefficient is greatest at higher wind speeds. Funded by grants OCE-0850663 and OCE-0748767 from the National Science Foundation.

  20. Phytoplankton blooms beneath the sea ice in the Chukchi sea

    NASA Astrophysics Data System (ADS)

    Arrigo, Kevin R.; Perovich, Donald K.; Pickart, Robert S.; Brown, Zachary W.; van Dijken, Gert L.; Lowry, Kate E.; Mills, Matthew M.; Palmer, Molly A.; Balch, William M.; Bates, Nicholas R.; Benitez-Nelson, Claudia R.; Brownlee, Emily; Frey, Karen E.; Laney, Samuel R.; Mathis, Jeremy; Matsuoka, Atsushi; Greg Mitchell, B.; Moore, G. W. K.; Reynolds, Rick A.; Sosik, Heidi M.; Swift, James H.

    2014-07-01

    In the Arctic Ocean, phytoplankton blooms on continental shelves are often limited by light availability, and are therefore thought to be restricted to waters free of sea ice. During July 2011 in the Chukchi Sea, a large phytoplankton bloom was observed beneath fully consolidated pack ice and extended from the ice edge to >100 km into the pack. The bloom was composed primarily of diatoms, with biomass reaching 1291 mg chlorophyll a m-2 and rates of carbon fixation as high as 3.7 g C m-2 d-1. Although the sea ice where the bloom was observed was near 100% concentration and 0.8-1.2 m thick, 30-40% of its surface was covered by melt ponds that transmitted 4-fold more light than adjacent areas of bare ice, providing sufficient light for phytoplankton to bloom. Phytoplankton growth rates associated with the under-ice bloom averaged 0.9 d-1 and were as high as 1.6 d-1. We argue that a thinning sea ice cover with more numerous melt ponds over the past decade has enhanced light penetration through the sea ice into the upper water column, favoring the development of these blooms. These observations, coupled with additional biogeochemical evidence, suggest that phytoplankton blooms are currently widespread on nutrient-rich Arctic continental shelves and that satellite-based estimates of annual primary production in waters where under-ice blooms develop are ~10-fold too low. These massive phytoplankton blooms represent a marked shift in our understanding of Arctic marine ecosystems.

  1. Sea Otter Pup Wants the Worm

    A sea otter pup watches eagerly as its mother eats a fat innkeeper worm in Monterey Bay, California. USGS scientists study sea otters in efforts to help the threatened species continue to recover from near extinction....

  2. Antarctic sea ice mapping using the AVHRR

    SciTech Connect

    Zibordi, G. ); Van Woert, M.L. . SeaSpace, Inc.)

    1993-08-01

    A sea ice mapping scheme based on Advanced Very High Resolution Radiometer (AVHRR) data from the National Oceanic and Atmospheric Administration (NOAA) polar orbiting satellites has been developed and applied to daylight images taken between November 1989 to January 1990 and November 1990 to January 1991 over the Weddell and the Ross Seas. After masking the continent and ice shelves, sea ice is discriminated from clouds and open sea using thresholds applied to the multidimensional space formed by AVHRR Channel 2, 3, and 4 radiances. Sea ice concentrations in cloud-free regions are then computed using the tie-point method. Results based on the analysis of more than 70 images show that the proposed scheme is capable of properly discriminating between sea ice, open sea, and clouds, under most conditions, thus allowing high resolution sea ice maps to be produced during the austral summer season.

  3. Sea-Floor Spreading and Transform Faults

    ERIC Educational Resources Information Center

    Armstrong, Ronald E.; And Others

    1978-01-01

    Presents the Crustal Evolution Education Project (CEEP) instructional module on Sea-Floor Spreading and Transform Faults. The module includes activities and materials required, procedures, summary questions, and extension ideas for teaching Sea-Floor Spreading. (SL)

  4. 50 CFR 648.11 - At-sea sea sampler/observer coverage.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 50 Wildlife and Fisheries 12 2013-10-01 2013-10-01 false At-sea sea sampler/observer coverage. 648.11 Section 648.11 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION, DEPARTMENT OF COMMERCE FISHERIES OF THE NORTHEASTERN UNITED STATES General Provisions § 648.11 At-sea sea...

  5. Sensitivity study of a dynamic thermodynamic sea ice model

    SciTech Connect

    Holland, D.M.; Mysak, L.A.; Manak, D.K. )

    1993-02-15

    A numerical simulation of the seasonal sea ice cover in the Arctic Ocean and the Greenland, Iceland, and Norwegian seas is presented. The sea ice model is extracted from Oberhuber's (1990) coupled sea ice-mixed layer-isopycnal general circulation model and is written in spherical coordinates. The advantage of such a model over previous sea ice models is that it can be easily coupled to either global atmospheric or ocean general circulation models written in spherical coordinates. In this model, the thermodynamics are a modification of that of Parkinson and Washington, while the dynamics use the full Hibler viscous-plastic rheology. Monthly thermodynamic and dynamic forcing fields for the atmosphere and ocean are specified. The simulations of the seasonal cycle of ice thickness, compactness, and velocity, for a control set of parameters, compare favorably with the known seasonal characteristics of these fields. A sensitivity study of the control simulation of the seasonal sea ice cover is presented. The sensitivity runs are carried out under three different themes, namely, numerical conditions, parameter values, and physical processes. This last theme refers to experiments in which physical processes are either newly added or completely removed from the model. Approximately 80 sensitivity runs have been performed in which a change from the control run environment has been implemented. Comparisons have been made between the control run and a particular sensitivity run based on time series of the seasonal cycle of the domain-averaged ice thickness, compactness, areal coverage, and kinetic energy. In addition, spatially varying fields of ice thickness, compactness, velocity, and surface temperature for each season are presented for selected experiments. A brief description and discussion of the more interesting experiments are presented. The simulation of the seasonal cycle of Arctic sea ice cover is shown to be robust. 31 refs., 20 figs., 5 tabs.

  6. Salton Sea Ecosystem Monitoring Project

    USGS Publications Warehouse

    Miles, A. Keith; Ricca, Mark A.; Meckstroth, Anne; Spring, Sarah E.

    2009-01-01

    The Salton Sea is critically important for wintering and breeding waterbirds, but faces an uncertain future due to water delivery reductions imposed by the Interstate and Federal Quantification Settlement Agreement of 2003. The current preferred alternative for wetland restoration at the Salton Sea is saline habitat impoundments created to mitigate the anticipated loss of wetland habitat. In 2006, a 50-hectare experimental complex that consisted of four inter-connected, shallow water saline habitat ponds (SHP) was constructed at the southeastern shoreline of the Salton Sea and flooded with blended waters from the Alamo River and Salton Sea. The present study evaluated ecological risks and benefits of the SHP concept prior to widespread restoration actions. This study was designed to evaluate (1) baseline chemical, nutrient, and contaminant measures from physical and biological constituents, (2) aquatic invertebrate community structure and colonization patterns, and (3) productivity of and contaminant risks to nesting waterbirds at the SHP. These factors were evaluated and compared with those of nearby waterbird habitat, that is, reference sites.

  7. Sea Lamprey, an Invasive Fish

    Invasive sea lamprey prey on commercially important fish species such as lake trout, living off of the blood and body fluids of adult fish.  It is one of many fish species that USGS scientists study from the USGS Research Vessel Muskie. These lamprey belong to the Great Lakes Fisheries Com...

  8. Sea Lamprey, an Invasive Fish

    Invasive sea lamprey prey on commercially important fish species such as lake trout, living off of the blood and body fluids of adult fish. It is one of many fish species that USGS scientists study from the USGS Research Vessel Muskie. These lamprey belong to the Great Lakes Fisheries Commissio...

  9. The Sea Ice Board Game

    ERIC Educational Resources Information Center

    Bertram, Kathryn Berry

    2008-01-01

    The National Science Foundation-funded Arctic Climate Modeling Program (ACMP) provides "curriculum resource-based professional development" materials that combine current science information with practical classroom instruction embedded with "best practice" techniques for teaching science to diverse students. The Sea Ice Board Game, described…

  10. Tides of the British Seas

    ERIC Educational Resources Information Center

    Sandon, Frank

    1975-01-01

    Examines the gravitational effects and the way that local conditions interact with these effects to produce the tides characteristic of the British seas. Presents some effects of tides including the possibility of harnessing tidal energy and the effect of tidal friction on the use of the earth as a clock. (GS)

  11. Sea Ice and Oceanographic Conditions.

    ERIC Educational Resources Information Center

    Oceanus, 1986

    1986-01-01

    The coastal waters of the Beaufort Sea are covered with ice three-fourths of the year. These waters (during winter) are discussed by considering: consolidation of coastal ice; under-ice water; brine circulation; biological energy; life under the ice (including kelp and larger animals); food chains; and ice break-up. (JN)

  12. Photonic aspect of sea shell

    NASA Astrophysics Data System (ADS)

    Sarkar, Aditi; Gangopadhyay, Arnab; Sarkar, A.

    2013-02-01

    Sea shells are the bio-originating layered tough shelters of mollusks. Optical aspects and the functional nature of it are studied in this work using experimental probes like Fourier transform infra-red spectroscopy (FTIR) and UVVIS spectroscopy. It shows Photonic behavior in IR region of electromagnetic wave. Corresponding photonic band gap is estimated.

  13. Ploughing the deep sea floor.

    PubMed

    Puig, Pere; Canals, Miquel; Company, Joan B; Martn, Jacobo; Amblas, David; Lastras, Galderic; Palanques, Albert

    2012-09-13

    Bottom trawling is a non-selective commercial fishing technique whereby heavy nets and gear are pulled along the sea floor. The direct impact of this technique on fish populations and benthic communities has received much attention, but trawling can also modify the physical properties of seafloor sediments, watersediment chemical exchanges and sediment fluxes. Most of the studies addressing the physical disturbances of trawl gear on the seabed have been undertaken in coastal and shelf environments, however, where the capacity of trawling to modify the seafloor morphology coexists with high-energy natural processes driving sediment erosion, transport and deposition. Here we show that on upper continental slopes, the reworking of the deep sea floor by trawling gradually modifies the shape of the submarine landscape over large spatial scales. We found that trawling-induced sediment displacement and removal from fishing grounds causes the morphology of the deep sea floor to become smoother over time, reducing its original complexity as shown by high-resolution seafloor relief maps. Our results suggest that in recent decades, following the industrialization of fishing fleets, bottom trawling has become an important driver of deep seascape evolution. Given the global dimension of this type of fishery, we anticipate that the morphology of the upper continental slope in many parts of the worlds oceans could be altered by intensive bottom trawling, producing comparable effects on the deep sea floor to those generated by agricultural ploughing on land. PMID:22951970

  14. [Medical emergencies and sea rescue].

    PubMed

    Lefebvre, Fabien; Albert, Christophe; Gunepin, David; Pondaven, Eric; Querellou, Emgan

    2013-01-01

    Military nurses and doctors are on permanent standby to respond to any medical emergency which may arise at sea. This atypical form of practice is part of a specific organisation, in order to provide optimal, high-quality care in the most remote places of the oceans. PMID:23951619

  15. Navigating the Seas of Policy.

    ERIC Educational Resources Information Center

    Cunningham, Stephanie; Kennedy, Steve; McAlonan, Susan; Hotchkiss, Heather

    As the sun, moon, and stars helped sea captains to navigate, policy (defined as a formalized idea to encourage change) indicates general direction and speed but does not establish a specific approach to achieve implementation. Formal and informal policies have advantages and disadvantages. These are steps in navigating policy formation: identify…

  16. A Deep-Sea Simulation.

    ERIC Educational Resources Information Center

    Montes, Georgia E.

    1997-01-01

    Describes an activity that simulates exploration techniques used in deep-sea explorations and teaches students how this technology can be used to take a closer look inside volcanoes, inspect hazardous waste sites such as nuclear reactors, and explore other environments dangerous to humans. (DDR)

  17. 33 CFR 2.22 - Territorial sea.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false Territorial sea. 2.22 Section 2.22 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY GENERAL JURISDICTION Jurisdictional Terms § 2.22 Territorial sea. (a) With respect to the United States, the following apply— (1) Territorial sea means the waters,...

  18. Sea Turtle Tracks at Nesting Site

    A morning photo depicts evidence of a sea turtle nesting the previous night (from the sea, left; return to sea, right). The protective stakes mark a nest from an earlier week as part of a county research program that marks and records every eighth nest....

  19. 50 CFR 223.205 - Sea turtles.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... (16 U.S.C. 1538) relating to endangered species apply to threatened species of sea turtle, except as... section; (5) Fail to follow any of the sea turtle handling and resuscitation requirements specified in § 223.206(d)(1); (6) Possess a sea turtle in any manner contrary to the handling and...

  20. 50 CFR 223.205 - Sea turtles.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... (16 U.S.C. 1538) relating to endangered species apply to threatened species of sea turtle, except as... section; (5) Fail to follow any of the sea turtle handling and resuscitation requirements specified in § 223.206(d)(1); (6) Possess a sea turtle in any manner contrary to the handling and...

  1. 50 CFR 223.205 - Sea turtles.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... (16 U.S.C. 1538) relating to endangered species apply to threatened species of sea turtle, except as... section; (5) Fail to follow any of the sea turtle handling and resuscitation requirements specified in § 223.206(d)(1); (6) Possess a sea turtle in any manner contrary to the handling and...

  2. [Comparative analysis of sea-ice diatom species composition in the seas of Russian Arctic].

    PubMed

    Il'iash, L V; Zhitina, L S

    2009-01-01

    Comparative analysis of species composition of ice diatom algae (IDA) of the White, Barents, Kara, Laptev, East Siberian, Chukchi Seas and the Basin of the Arctic Ocean was conducted on the basis of both original and published data. Species composition of IDA counts 567 taxa including 122 centric and 446 pennate diatoms. The freshwater algae composed about 18% of the total species number. In the White Sea, IDA were the most numerous (272 taxa), in the Kara Sea they are the least numerous (57 taxa). The species compositions in different seas differ significantly from each other. Similarity of IDA was consistent with the Arctic Ocean circulation and ice drift. IDA of Chukchi, East Siberian and Laptev Seas are the most similar, as are IDA of White and Kara Seas. Similarity of IDA of Chukchi Sea to those of other seas decrease in the west direction. IDA species differences between regions within one sea could be greater than those between different seas. PMID:19425351

  3. Management of the Wadden Sea

    NASA Astrophysics Data System (ADS)

    Wolff, W. J.; Zijlstra, J. J.

    1980-03-01

    The Wadden Sea situated along the North Sea coasts of Denmark, the Federal Republic of Germany and The Netherlands represents one of the world's largest bar-built type of estuaries. The area is a typical sedimentation and mineralization basin, with a large influx of organic matter from the adjoining North Sea, consequently a delicate oxygen balance and a rich benthic macrofauna, poor in species, which serves as food for juveniles of some commercially important North Sea fishes and for large numbers of migrating and wintering waders and waterfowl. Past and present activities of the human society in the area include fisheries (mainly for shrimp and mussels, semi-culture), shipping, land reclamation, recreation, dredging for sand and shells, and waste discharge from industries and human communities. Until the present these activities, although sometimes conflicting, did not fundamentally affect the area and its biota (pollution excluded), but future claims, including the construction of large deep-sea harbours, drilling for natural gas and oil, large-scale land reclamation and increased industrialization etc., might gradually induce degradation. For instance, area reduction by continued land reclamation could lead to irreversible losses of specific biotopes (e. g. salt-marshes, mud-flats), which could affect the size of bird and fish populations in a much wider region. Increased pollution, which has already inflicted damage on bird and seal populations, could reduce the fauna and hence the value of the area as a natural sanctuary. In the event of a proposal for a new human activity in the area, the present standing practice in the countries concerned requires an evaluation of its safety and economic aspects and its environmental impact. However, the various plans are considered separately and there is a general need for integrated management of the area.

  4. Facing up to sea rise.

    PubMed

    Pernetta, J

    1994-01-01

    A milder and less extreme climate, abundance of fish and mollusks, transport and communication, and fertile land at low altitudes have drawn humans to coastal areas and river valleys for centuries. More than 60% of the world's population occupy the 150 km closest to the coast. Millions of tourists come to coastlines and small tropical islands for recreation. About 80% of the global fish supply originates from the 19 km closest to the shore. Fish are the only protein source for the rapidly growing populations in many developing countries. Global climate change is increasing the sea level so much that by 2050, the mean increase will be about 38 cm (24-52 cm). The Intergovernmental Panel on Climate Change (IPCC) notes that the effects of sea level rise will differ from place to place. Direct effects are flooding of low-lying coastal areas and increased erosion rates. An indirect effect includes higher water tables and intrusion of saline water into aquifers, resulting in loss of fresh ground water resources. These effects may make coastal areas less suitable for settlement and agriculture. Coral sand settled on top of coral reefs makes up the unstable, small atoll islands of the Pacific and Indian Oceans. People on these islands depend almost entirely on the sea for their livelihood and on the small amount of fresh water with which they grow root crops and drink. Rising sea levels also threaten low lying countries, e.g., Bangladesh, and densely populated deltas, e.g., the Nile. Changes in the frequency and severity of flooding will increase Bangladesh's dependence on foreign aid. IPCC sees 3 possible responses to the rising sea level: defense, retreat, and accommodation. Accommodation is the only practical choice for many developing countries. A switch from rice cultivation to mariculture of prawns and fish is an example of accommodation. We need to more completely understand the natural processes in coastal environments to be better prepared for climate change. PMID:12287486

  5. Thermal biology of sea snakes and sea kraits.

    PubMed

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

    2012-08-01

    Temperature probably had no direct effect on the evolution of sea kraits within their center of origin, a geologically stable thermal zone straddling the equator, but may have indirectly affected expansions and contractions in distributions beyond that zone through global fluctuations that caused alternation of higher and lower sea levels. The northern limit of the Laticauda colubrina complex seems to be the 20°C isotherm; in the south, the range does not reach that isotherm because there is no land (also a habitat requirement of sea kraits) within the zone of suitable temperature. The relationship of temperature to the pattern of geographic variation in morphology supports either the hypothesis of peripheral convergence or the developmental hypothesis but does not distinguish between them. Quadratic surfaces relating cumulative scores for coloration and morphological characters to global position showed a strong latitudinal component and an even stronger longitudinal one in which the direction of the latitudinal effect was reversed between east and west. A multivariate analysis revealed that while morphological characters vary significantly by location and climate when tested separately, when the influence of location on morphology is taken into account, no residual relationship between climate and morphology remains. Most marine snakes have mean upper temperature tolerances between 39°C and 40°C and operate at temperatures much nearer their upper thermal limits than their lower limits but still avoid deleterious extremes by diving from excessively hot water to deeper, cooler strata, and by surfacing when water is cold. At the surface in still water in sunlight, Pelamis can maintain its body temperature slightly above that of the water, but whether this is significant in nature is questionable. As temperature falls below 18-20°C, survival time is progressively reduced, accompanied by the successive occurrence of cessation of feeding, cessation of swimming, and failure to orient. Acclimation does not seem to be in this species' repertoire. In the water column, marine snakes track water temperature; on land, sea kraits can thermoregulate by basking, selecting favorable locations, and by kleptothermy. Laticauda colubrina adjusts its reproductive cycle geographically in ways that avoid breeding in the coldest months. Mean voluntary diving time is not temperature-dependent within the normal range of temperatures experienced by marine snakes in the field, but is reduced in water colder than 20°C. On land, much as while diving in the sea, sea kraits maintain long periods of apnea; intervals between breaths are inversely related to temperature. PMID:22669175

  6. Distribution characteristics of marine litter on the sea bed of the East China Sea and the South Sea of Korea

    NASA Astrophysics Data System (ADS)

    Lee, Dae-In; Cho, Hyeon-Seo; Jeong, Sun-Beom

    2006-10-01

    The types, quantities, and distribution of marine litter found on the sea bed of the East China Sea and the South Sea of Korea are surveyed. Surveys were evaluated using bottom trawl nets during 1996-2005 cruises. Mean distribution densities were high in coastal seas, especially in the South Sea of Korea offshore from Yeosu, with 109.8 kg km -2, and low in the East China Sea, with densities of 30.6 kg km -2. Fishing gear, such as pots, nets, octopus jars, and fishing lines, accounted for about 42-72% and 37-62% of litter items in the East China Sea and the South Sea of Korea, respectively, whereas the contributions of rubber, vinyl, metal, plastic, glass, wood, and clothing were below 30% mainly. Rope and drum composition fluctuated greatly, between 54% and 0%. Eel and net pots dominated the marine debris of the South Sea of Korea, and some vinyl, plastics, and fishing gear made in Korea, China, and Japan were collected in abundance in the East China Sea. Fishing gear was probably discarded into the sea, deliberately or inadvertently, by fishing operations. A comprehensive joint approach by Korea, China, and Japan is needed for the continuous monitoring of input sources, the actual conditions, and the behavior of marine litter for protection against litter pollution and fisheries resource management in this area.

  7. Polar low climatology over the Nordic and Barents seas based on satellite passive microwave data

    NASA Astrophysics Data System (ADS)

    Smirnova, Julia E.; Golubkin, Pavel A.; Bobylev, Leonid P.; Zabolotskikh, Elizaveta V.; Chapron, Bertrand

    2015-07-01

    A new climatology of polar lows over the Nordic and Barents seas for 14 seasons (1995/1996-2008/2009) is presented. For the first time in climatological studies of polar lows an approach based on satellite passive microwave data was adopted for polar low identification. A total of 637 polar lows were found in 14 extended winter seasons by combining total atmospheric water vapor content and sea surface wind speed fields retrieved from Special Sensor Microwave/Imager data. As derived, the polar low activity in the Norwegian and Barents Seas is found to be almost equal, and the main polar low genesis area is located northeastward of the North Cape. For the Barents Sea, a significant correlation is found between the number of polar lows and mean sea ice extent. Individual indicative polar low characteristics (i.e., diameter, lifetime, distance traveled, translation speed, and maximum wind speed) are also presented.

  8. On the Sea, From the Sea, Of the Sea: The Physics of maritime Governance

    NASA Astrophysics Data System (ADS)

    James, Royce; Page, Eric

    2014-03-01

    The United States Coast Guard Academy Physics Section is proud to present our initial conceptions of ``On the Sea, From the Sea, Of the Sea: The Physics of Maritime Governance,'' a program funded by an APS Outreach Grant in 2013. In our classes, the Physics Section has focused on active student engagement for the past ten years. Recently, we have refined our program to make heavy use of Interactive Lecture Demonstrations (ILDs) and our own highly interactive adaptation which we call Interactive Lecture Labs (ILLs). ``On the Sea'' is a unique opportunity to investigate their use in a different learning modality from our standard college level military academic use. Multigenerational science, technology, engineering, and mathematics (STEM) projects are a prolific source of academic discourse, while learning through play has been touted as an effective learning tool. We plan to investigate group and individual participation, intragroup communication, demographics, and prior skill (or education) in comparison to outcomes in learning objectives through projects designed to educate the Coast Guard Academy and surrounding community on the physics of the Coast Guard's missions. Progress on the lab and demonstration designs, community participation, and our emerging ILL and ILD pedagogical methods, will be reported.

  9. Sea Ice Thickness Variability in Fram Strait

    NASA Astrophysics Data System (ADS)

    Gerland, S.; Renner, A.; Haas, C.; Nicolaus, M.; Granskog, M.; Hansen, E.; Hendricks, S.; Hudson, S. R.; Beckers, J.; Goodwin, H.

    2011-12-01

    On this poster, we show results from airborne electromagnetic (EM) sea ice thickness measurements demonstrating the temporal and spatial complexity of the ice thickness distribution in Fram Strait between Greenland and Svalbard. Knowledge about the spatial and temporal sea ice thickness distribution in the Arctic Ocean is necessary to assess the state of the sea-ice cover, and to understand relevant processes and changes. Since 2003, the Norwegian Polar Institute (NPI) has been conducting systematic in situ monitoring of sea ice thickness in the western Fram Strait, using both ground and airborne techniques. Fram Strait is a key region for large-scale ice dynamics in the Arctic. It represents the main export route for sea ice from the Arctic and the only deep strait connecting the interior Arctic Ocean and the rest of the world oceans. The ice thickness distribution in this region is the result of a combination of dynamic and thermodynamic sea ice processes. Transects for airborne EM observations were flown by NPI in spring 2005, 2008, and late summer 2010, and by the Alfred Wegener Institute in spring 2009. The regional ice thickness distributions are supplemented with ground measurements including snow thickness observations taken on ice stations during ship expeditions in spring 2005, 2007, and 2008 and annually in late summer from 2003 to 2011. From all these observations, we can show the differing characteristics of the thickness distributions in spring (2005, 2008, 2009) and late summer (2010) when the ice thickness is at its annual maximum (end of the freezing period) and minimum (end of the melting period), respectively. The ice thickness distribution can also vary spatially over short distances in north-south direction. Features such as the East Greenland Polynya, which varies in size for a given time from year to year, contribute to the spatial and temporal variability on the Greenlandic Shelf. In spring 2005, a gradient is visible across Fram Strait from thinner pack ice at the eastern ice edge towards thicker pack ice on the Greenland shelf in the western part of Fram Strait with thick multiyear ice. The spring modal thickness ranged from about 2 m to 3.5 m. In contrast, the spatial variability of the modal thickness in 2008 is larger than observed in the previous campaigns with a wider range of modal ice thicknesses, predominantly due to thinner ice than in 2005. Finally, during late summer 2010 modal thicknesses in the central and eastern part of Fram Strait ranged from about 1 to 2 m. At the same time distributions were in general narrower than observed in previous years, showing a decrease of the fraction of thick pressure ridges. Thick ice was measured only in the westernmost part of Fram Strait. These observations are in agreement with a reported trend towards a generally larger amount of first-year ice versus multiyear ice in the Arctic.

  10. Antivenom in sea-snake bit poisoning.

    PubMed

    Reid, H A

    1975-03-15

    Among a series of 101 patients bitten by sea-snakes in Malaya in the years 1957-64, 80% were fishermen. Bathers and divers are occasionally bitten. Before sea-snake antivenom became available the mortality-rate (despite the high toxicity of sea-snake venom) was only 10%; however, of 11 with serious poisoning, 6 died. Subsequently 10 patients with serious poisoning received specific sea-snake antivenom; 2 patients, admitted moribund, temporarily improved but died, and 8 patients recovered dramatically. In serious poisoning the suitable dosage of intravenous sea-snake antivenom is 3000-10,000 units; in mild poisoning 1000-2000 units should suffice. PMID:47960

  11. Compaction of North-sea chalk

    NASA Astrophysics Data System (ADS)

    Keszthelyi, Dániel; Dysthe, Dag Kristian; Jamtveit, Bjørn

    2014-05-01

    The Ekofisk field is the largest petroleum field in the Norwegian North Sea territory where oil is produced from chalk formations. Early stage of oil production caused considerable changes in pore fluid pressure which led to a reservoir compaction. Pore collapse mechanism caused by the dramatic increase of effective stress, which in turn was caused by the pressure reduction by hydrocarbon depletion, was early identified as a principal reason for the reservoir compaction (Sulak et al. 1991). There have been several attempts to model this compaction. They performed with variable success on predicting the Ekofisk subsidence. However, the most of these models are based on empirical relations and do not investigate in detail the phenomena involved in the compaction. In sake of predicting the Ekofisk subsidence while using only independently measurable variables we used a chalk compaction model valid on geological time-scales (Japsen et al. 2011) assuming plastic pore-collapse mechanism at a threshold effective stress level. We identified the phenomena involved in the pore collapse. By putting them in a sequential order we created a simple statistical analytical model. We also investigated the time-dependence of the phenomena involved and by assuming that one of the phenomena is rate-limiting we could make estimations of the compaction rate at smaller length-scales. By carefully investigating the nature of pressure propagation we could upscale our model to reservoir scale. We found that the predicted compaction rates are close enough to the measured rates. We believe that we could further increase accuracy by refining our model. Sulak, R. M., Thomas, L. K., Boade R. R. (1991) 3D reservoir simulation of Ekofisk compaction drive. Journal of Petroleum Technology, 43(10):1272-1278, 1991. Japsen, P., Dysthe, D. K., Hartz, E. H., Stipp, S. L. S., Yarushina, V. M., Jamtveit. (2011) A compaction front in North Sea chalk. Journal of Geophysical Research: Solid Earth (1978-2012), 116(B11)

  12. Sea level trends and interannual variability in the Caribbean Sea

    NASA Astrophysics Data System (ADS)

    Torres, R.; Tsimplis, M.

    2012-04-01

    Sea level trends and interannual variability has been investigated in the Caribbean Sea using altimetry and tide gauge time series from 19 stations. Relative sea level trends range between -2.0 and 10.7 mm/y depending on the length of the available record. Records from stations longer than 40 years converge toward values between 1.2 - 5.2 mm/yr, still a significant range which in some stations is less and in some other significantly larger than the global average. The longest station, Cristobal (102 years) shows a trend of 1.9 mm/yr and, in addition a significant acceleration of 1.6±0.3 mm/y/cy. The observed sea level trends are not affected by the atmospheric pressure effect, within the levels of significance. They are also the same (within the levels of significance) at all seasons. Altimetry shows trends (over 18 years of data) with values up to 5.2 mm/y. In some areas the values are statistically insignificant, but at no areas statistically significant negative values are found. Steric trends from the top 800 m (over the period of altimetric observations) have a basin average trend of 1 mm/y, but it shows large spatial variability with negative trends of -7 mm/y in the Yucatan Basin and positive trends up to 4.9 mm/y in the Venezuela Basin. Decadal trends were found to vary significantly at tide-gauge records as well as altimetric and steric measurements. We further explore the residual interannual variability by comparison with surface wind and climatic indices. This analysis is supported by the Lloyd's Register Trust Fund project Marine Extremes.

  13. The distribution and diversity of sea cucumbers in the coral reefs of the South China Sea, Sulu Sea and Sulawesi Sea

    NASA Astrophysics Data System (ADS)

    Woo, Sau Pinn; Yasin, Zulfigar; Ismail, Siti Hasmah; Tan, Shau Hwai

    2013-11-01

    A study on the distribution and diversity of sea cucumbers in the coral reefs of the South China Sea, Sulu Sea and Sulawesi Sea was carried out in July 2009. The survey was done using wandering transect underwater with SCUBA. Twelve species of sea cucumber were found from four different families and nine genera. The most dominant family was Holothuriidae (five species), followed by Stichopodidae (three species), Synaptidae (three species) and Cucumariidae with only one species. The most dominant species found around the island was Pearsonothuria graffei, which can be found abundantly on substrate of dead corals in a wide range of depth (6-15 m). The Sulawesi Sea showed a higher diversity of sea cucumber with seven different species compared to the South China Sea with only six different species and Sulu Sea with only two species. Ordination by multidimensional scaling of Bray-Curtis similarities clustered the sampling locations to three main clusters with two outgroups. Previous studies done indicated a higher diversity of sea cucumber as compared to this study. This can be indication that the population and diversity of sea cucumbers in the reef is under threat.

  14. Climate modulation on sea surface height in China seas

    NASA Astrophysics Data System (ADS)

    Zhang, Xiaoshuang; Wang, Xidong; Cao, Yingzhi; Zhang, Lianxin; Shao, Caixia; Sun, Chunjian; Wu, Xinrong; Fu, Hongli; Xuan, Lili

    2015-09-01

    The climate modulation on the sea surface height (SSH) in China seas is investigated using a China Ocean Reanalysis (CORA) dataset from 1958-2008. The dataset is constructed by assimilating the temperature/salinity profiles derived from the satellite altimetry data and historical observational temperature/salinity profiles. Based on the Empirical Orthogonal Function (EOF), the CORA sea surface height anomaly (SSHa) is decomposed, and the interannual and decadal variability of the first three leading modes are analyzed. On the interannual timescale, the first principal component (PC1) is significant positively correlated with the El Niño/Southern Oscillation (ENSO). On the decadal timescale, North Pacific Gyre Oscillation (NPGO) has significant negative correlation with PC1 whereas Pacific Decadal Oscillation (PDO) is in phase with PC3. Analysis shows that the decadal variability of SSH is mainly modulated by the wind stress curl variability related to the NPGO and PDO. In addition, the effect of net heat flux associated to the NPGO and PDO on SSH is also investigated, with net heat flux variability in the Luzon strait and tropic Pacific found to influence the decadal variability of SSH.

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

    PubMed

    Mikac, Barbara

    2015-01-01

    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. PMID:25947537

  16. Winter snow cover on sea ice in the Weddell Sea

    NASA Astrophysics Data System (ADS)

    Massom, Robert A.; Drinkwater, Mark R.; Haas, Christian

    1997-01-01

    Measurements of snow thickness, temperature, salinity, density, and stratigraphy acquired during the 1992 Winter Weddell Gyre Study are presented. Results indicate that the winter snow cover on sea ice in the Weddell Sea is extremely variable. Extreme fluctuations in Antarctic synoptic conditions (air temperature, precipitation, humidity, and wind speed) occur during the austral winter. They result in unique modifications and additions to the snow layer during the aging process and act to stabilize an otherwise easily wind-redistributed shallow snow cover and develop well-packed drift features. The latter occur even over relatively undeformed areas of sea ice and have a significant localized effect on the snow thickness distribution. Significant variability in snow grain size (mean 2.733.12 mm) and density (0.320.09 g cm-3) is observed as a result of cyclical switches between high- and low-temperature gradient metamorphism. Multiple icy layers indicate multiple thaw-freeze events. One such event occurred during a 3-day station, during which the air temperature rose by 22C in 12 hours (to approximately 0C). This paper also examines mechanisms for flooding of the snow-ice interface, including snow loading. Even where the latter is not a factor, the layer of snow immediately above the snow-ice interface is commonly damp and saline (>10). Limitations in the data set are discussed, and comparisons are drawn with other experiments.

  17. Sea bottom scouring in the Canadian Beaufort Sea

    SciTech Connect

    Hnatiuk, J.; Wright, B.D.

    1983-05-01

    Echo sounding, side scan sonar and seismic profiling records have shown that the continental shelf of the Canadian Beaufort Sea has been subjected to extensive scouring by ice features. The scouring phenomena is extremely important in the design and protection of offshore wells and future pipelines. Analyses of records collected by industry and government in the early 1970's and reported by Hnatiuk and Brown in 1977 have been refined with the inclusion of additional data collected by industry and government in 1975 and 1976. Here, the results of the information synthesis are presented in terms of regional maps showing relevant scouring parameters and their variation with location and water depth. A quantitative evaluation of scour return period is also presented on the basis of sedimentation assumptions. This information is compared with a recent analysis of side scan scour mosaics collected repetitively over four areas ranging in water depths from 45 to 150 feet and with time intervals ranging from 2 to 7 years between the repetitive seafloor maps. The rate of addition of new scours determined from the repetitive mosaic approach supports the regional assessment of Beaufort Sea scour but suggests more episodic and areally frequent scour events along with more active scouring in water depths approaching 150 feet. This information is discussed in terms of the Beaufort Sea ice regime.

  18. Intermediate water ventilation in the Nordic seas during MIS 2

    NASA Astrophysics Data System (ADS)

    RRvik, Kari-Lise; Rasmussen, Tine L.; Hald, Morten; Husum, Katrine

    2013-05-01

    A high-resolution marine record from the northern Norwegian continental margin off Lofoten is used to reconstruct changes in the oceanography of the Nordic seas during marine isotope stage (MIS) 2 including the Last Glacial Maximum and early deglaciation circa 25 to 16 ka. The period was characterized by generally warm subsurface water temperatures >2C and inflow of Atlantic surface water. Several events were characterized by decrease in ventilation of the intermediate water and low subsurface temperature and salinity. They correlate with colder atmospheric temperatures as seen in ice cores. The events terminated with gradual strengthening of the intermediate water ventilation and increase in subsurface temperature. The generation of intermediate water was unstable and experienced climate and ventilation changes on millennial and centennial timescales. The changes appear consistent with modeling experiments that predict short-lasting circulation stops during MIS 2 due to release of meltwater in the Nordic seas.

  19. Sea ice density estimation in the Bohai Sea using the hyperspectral remote sensing technology

    NASA Astrophysics Data System (ADS)

    Liu, Chengyu; Shao, Honglan; Xie, Feng; Wang, Jianyu

    2014-11-01

    Sea ice density is one of the significant physical properties of sea ice and the input parameters in the estimation of the engineering mechanical strength and aerodynamic drag coefficients; also it is an important indicator of the ice age. The sea ice in the Bohai Sea is a solid, liquid and gas-phase mixture composed of pure ice, brine pockets and bubbles, the density of which is mainly affected by the amount of brine pockets and bubbles. The more the contained brine pockets, the greater the sea ice density; the more the contained bubbles, the smaller the sea ice density. The reflectance spectrum in 350~2500 nm and density of sea ice of different thickness and ages were measured in the Liaodong Bay of the Bohai Sea during the glacial maximum in the winter of 2012-2013. According to the measured sea ice density and reflectance spectrum, the characteristic bands that can reflect the sea ice density variation were found, and the sea ice density spectrum index (SIDSI) of the sea ice in the Bohai Sea was constructed. The inversion model of sea ice density in the Bohai Sea which refers to the layer from surface to the depth of penetration by the light was proposed at last. The sea ice density in the Bohai Sea was estimated using the proposed model from Hyperion image which is a hyperspectral image. The results show that the error of the sea ice density inversion model is about 0.0004 g•cm-3. The sea ice density can be estimated through hyperspectral remote sensing images, which provide the data support to the related marine science research and application.

  20. Lithosphere-scale 3D gravity modelling of the Barents Sea and Kara Sea

    NASA Astrophysics Data System (ADS)

    Klitzke, P.; Faleide, J.; Sippel, J.; Scheck-Wenderoth, M.

    2013-12-01

    The Barents - Kara Sea region covers the major part of the European Arctic shelf. Its northern and western boundaries are young passive margins which originate from early Paleocene-Eocene opening of the Eurasia Basin and the Norwegian-Greenland Sea. In contrast, the basement of the Barents and Kara shelves has been consolidated much earlier, during three major late Precambrian to Permian orogenies. Additionally, the shelf experienced multiple episodes of localised subsidence which resulted in the formation of ultra-deep sedimentary basins varying strongly in their geometry between different subregions. Consequently, the preserved sedimentary record is interrupted by major megasequence boundaries that are well-described in the western Barents Sea. Using this subdivision for the sedimentary record, we traced four major megasequence boundaries across the Barents and Kara shelves by analysing interpreted seismic refraction and reflection data, geological maps and previously published 3D-models. We integrate this shallow information into a 3D geological model and complement the latter downward with the top crystalline crust, the Moho and a new lithosphere-asthenosphere boundary. The sedimentary units have been assigned physical properties considering the respective lithology to calculate a depth-dependent density distribution. Thereby, the obtained bulk densities also account for late Cenozoic uplift/erosion and the maximum Pleistocene ice sheet thickness. For the lithospheric mantle, the density distribution is constrained by an earlier published velocity model (Levshin et al., 2007). On the base of isostatic calculations and 3D gravity modelling the density configuration of the crystalline crust and the geometry of potential high-density bodies is investigated. Finally, we correlate preserved sediment maxima and reconstructed erosion maps with subsedimentary velocity and density variations to gain new insights into the development of Barents and Kara Sea basins. Levshin, A. L., Schweitzer, J., Weidle, C., Shapiro, N. M., & Ritzwoller, M. H. (2007). Surface wave tomography of the Barents Sea and surrounding regions. Geophysical Journal International, 170(1), 441-459. doi:10.1111/j.1365-246X.2006.03285.x

  1. Influence of sea level rise on the dynamics of salt inflows in the Baltic Sea

    NASA Astrophysics Data System (ADS)

    Hordoir, Robinson; Axell, Lars; Löptien, Ulrike; Dietze, Heiner; Kuznetsov, Ivan

    2015-10-01

    The Baltic Sea is a marginal sea, located in a highly industrialized region in Central Northern Europe. Saltwater inflows from the North Sea and associated ventilation of the deep exert crucial control on the entire Baltic Sea ecosystem. This study explores the impact of anticipated sea level changes on the dynamics of those inflows. We use a numerical oceanic general circulation model covering both the Baltic and the North Sea. The model successfully retraces the essential ventilation dynamics throughout the period 1961-2007. A suite of idealized experiments suggests that rising sea level is associated with intensified ventilation as saltwater inflows become stronger, longer, and more frequent. Expressed quantitatively as a salinity increase in the deep central Baltic Sea, we find that a sea level rise of 1 m triggers a saltening of more than 1 PSU. This substantial increase in ventilation is the consequence of the increasing cross section in the Danish Straits amplified by a reduction of vertical mixing.

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

    NASA Technical Reports Server (NTRS)

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

    2011-01-01

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

  3. Water masses and 129I distribution in the Nordic Seas

    NASA Astrophysics Data System (ADS)

    Alfimov, Vasily; Aldahan, Ala; Possnert, Göran

    2013-01-01

    The application of the radioactive isotope iodine-129 as a tracer of water circulation in the oceans has provided interesting information with respect to sources and mixing of different water masses. We here present results of 129I distribution in water profiles located in the Nordic Seas and use the isotope to fingerprint water masses in the region. The samples were collected by the US research vessel Knorr in May-June 2002. 129I signatures along the Norwegian Sea reflect a mixing of 129I-rich surface water along the Scandinavian continental slope and 129I-poor North Atlantic surface water. These two water masses become less segregated along the Fram Strait where apparent 129I enrichment penetrates the return Arctic flow into the East Greenland Current. The 129I data further suggest existence of a water mass that is not entirely labeled with respect to origin at the Denmark Strait bottom water. This water parcel probably originates from the Iceland Sea. 129I data also shed light on the major deep water outflow from the Nordic Seas located at the Faeroe Bank Channel.

  4. The Nordic seas: An overview

    NASA Astrophysics Data System (ADS)

    Drange, Helge; Dokken, Trond; Furevik, Tore; Gerdes, Rüdiger; Berger, Wolfgang; Nesje, Atle; Arild Orvik, Kjell; Skagseth, Øystein; Skjelvan, Ingunn; Østerhus, Svein

    The aim of this overview paper is to provide a brief synthesis of the five review papers contained in the monograph. Prevailing southwesterly winds, oceanic flow patterns, and oceanic summer heat storage make the temperatures of the Nordic Seas region 10—20°C above the mean temperature of locations at similar latitudes. The combination of the large heat import from the south plus the polar location implies that the region is prone to natural climate variations and is particularly vulnerable for external forcings. Indeed, proxy data for the Holocene epoch reveal large, high-frequency climate fluctuations, as well as long-term variations spanning the "Medieval Warm Period" and the "Little Ice Age". In phase with a strengthening of the westerly winds since the 1960s, several oceanic key variables show trends unprecedented in available instrumental records, some of which extend back 50—100 years. State-of-the-art climate models indicate that several of the changes may be linked to increased forcing of greenhouse gases and are therefore likely to be sustained or even amplified in the future. Furthermore, the marine cycling of carbon, and through that the major greenhouse gas carbon dioxide, is closely linked to the climate state of the region. The Nordic Seas region is, as one of few ocean locations, a sink for atmospheric carbon dioxide throughout the year. With the rapid developments in data acquisition, computational resources, and societal concerns for climate change and environmental issues, the review papers give an updated account of the present knowledge of the complex climate states of the Nordic Seas and how the Nordic Seas influence the climate outside the region.

  5. Sea Quarks in the Proton

    NASA Astrophysics Data System (ADS)

    Reimer, Paul E.

    2016-03-01

    The proton is a composite particle in which the binding force is responsible for the majority of its mass. To understand this structure, the distributions and origins of the quark-antiquark pairs produced by the strong force must be measured. The SeaQuest collaboration is using the Drell-Yan process to elucidate antiquark distributions in the proton and to study their modification when the proton is held within a nucleus.

  6. Salton Sea solar pond project

    NASA Technical Reports Server (NTRS)

    French, R. L.; Meitlis, I.

    1980-01-01

    The feasibility of constructing salt gradient solar ponds within the Salton Sea is being studied. These ponds would serve a dual purpose: (1) become a depository for unwanted salt and (2) supply thermal energy for driving turbine electric power systems. Under present circumstances, the rise in salinity is expected to eliminate fish life and create other unfavorable conditions. The proposed concept would have a power generation potential of 600 MWe.

  7. Medusa Sea Floor Monitoring System

    NASA Technical Reports Server (NTRS)

    Flynn, Michael

    2004-01-01

    The objective of the research described in this poster presentation is to develop technologies to enable fundamental research into understanding the potential for and limits to chemolithoautotrophic life. The Medusa Isosampler (isobaric sampler), for sampling fluids eminating from deep sea hydrothermal vents and cold seep sites analogous to extraterrestrial environments, is described by the presentation. The following instruments are integrated with the isosampler, and also described: in situ flow-through chemical sensor, intrinsic fluorescent-based microbial detector, isotope ratio spectral detector.

  8. Primary productivity in the sea

    SciTech Connect

    Falkowski, P.G.

    1980-01-01

    Recent progress in primary productivity is discussed in the book based on 27 symposia texts and 19 poster abstracts. Most papers deal with particular cellular processes in pelagic phytoplankton and their relationship to whole plant photosynthesis and growth. In addition, presentations on the productivity of the seaweed, Laminaria, zooxanthellae and whole corals are included. Other articles discuss predictive modeling, new developments in remote sensing, nutrient regeneration within the sea, grazing effects, and carbon cycling. (JMT)

  9. MODIS Global Sea Surface Temperature

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Every day the Moderate-resolution Imaging Spectroradiometer (MODIS) measures sea surface temperature over the entire globe with high accuracy. This false-color image shows a one-month composite for May 2001. Red and yellow indicates warmer temperatures, green is an intermediate value, while blues and then purples are progressively colder values. The new MODIS sea surface temperature product will be particularly useful in studies of temperature anomalies, such as El Nino, as well as research into how air-sea interactions drive changes in weather and climate patterns. In the high resolution image, notice the amazing detail in some of the regional current patterns. For instance, notice the cold water currents that move from Antarctica northward along South America's west coast. These cold, deep waters upwell along an equatorial swath around and to the west of the Galapagos Islands. Note the warm, wide currents of the Gulf Stream moving up the United States' east coast, carrying Caribbean warmth toward Newfoundland and across the Atlantic toward Western Europe. Note the warm tongue of water extending from Africa's east coast to well south of the Cape of Good Hope. MODIS was launched in December 1999 aboard NASA's Terra satellite. For more details on this and other MODIS data products, please see NASA Unveils Spectacular Suite of New Global Data Products from MODIS. Image courtesy MODIS Ocean Group, NASA GSFC, and the University of Miami

  10. Respiration in neonate sea turtles.

    PubMed

    Price, Edwin R; Paladino, Frank V; Strohl, Kingman P; Santidrián T, Pilar; Klann, Kenneth; Spotila, James R

    2007-03-01

    The pattern and control of respiration is virtually unknown in hatchling sea turtles. Using incubator-raised turtles, we measured oxygen consumption, frequency, tidal volume, and minute volume for leatherback (Dermochelys coriacea) and olive ridley (Lepidochelys olivacea) turtle hatchlings for the first six days after pipping. In addition, we tested the hatchlings' response to hypercapnic, hyperoxic, and hypoxic challenges over this time period. Hatchling sea turtles generally showed resting ventilation characteristics that are similar to those of adults: a single breath followed by a long respiratory pause, slow frequency, and high metabolic rate. With hypercapnic challenge, both species responded primarily by elevating respiratory frequency via a decrease in the non-ventilatory period. Leatherback resting tidal volume increased with age but otherwise, neither species' resting respiratory pattern nor response to gas challenge changed significantly over the first few days after hatching. At the time of nest emergence, sea turtles have achieved a respiratory pattern that is similar to that of actively diving adults. PMID:17258487

  11. Respiration in Neonate Sea Turtles

    PubMed Central

    Paladino, Frank V.; Strohl, Kingman P.; Pilar Santidrin, T.; Klann, Kenneth; Spotila, James R.

    2007-01-01

    The pattern and control of respiration is virtually unknown in hatchling sea turtles. Using incubator-raised turtles, we measured oxygen consumption, frequency, tidal volume, and minute volume for leatherback (Dermochelys coriacea) and olive ridley (Lepidochelys olivacea) turtle hatchlings for the first six days after pipping. In addition, we tested the hatchlings response to hypercapnic, hyperoxic, and hypoxic challenges over this time period. Hatchling sea turtles generally showed resting ventilation characteristics that are similar to those of adults: a single breath followed by a long respiratory pause, slow frequency, and high metabolic rate. With hypercapnic challenge, both species responded primarily by elevating respiratory frequency via a decrease in the non-ventilatory period. Leatherback resting tidal volume increased with age but otherwise, neither species resting respiratory pattern nor response to gas challenge changed significantly over the first few days after hatching. At the time of nest emergence, sea turtles have achieved a respiratory pattern that is similar to that of actively diving adults. PMID:17258487

  12. Could inland seas have remained free of sea-glacier derived ice during Snowball Earth events?

    NASA Astrophysics Data System (ADS)

    Campbell, A. J.; Waddington, E. D.; Warren, S. G.

    2010-12-01

    Robust geological evidence exists for periods during the Precambrian of global ocean glaciation, commonly referred to as Snowball Earth events. A difficulty of the Snowball Earth hypothesis is understanding how photosynthetic eukaryotic organisms survived during these events. While evidence exists for photosynthetic eukaryotic organisms both before and after Snowball Earth events, it is unknown where these organisms may have survived during these events. Sea-glaciers, many hundreds of meters thick, would have formed on the polar oceans and flowed equitorially. This thick glacier ice would not have permitted transmittance of light to the underlying ocean water. One proposal is that inland seas, analogous to the modern day Mediterranean Sea, may have persisted at low latitudes, covered only by a few meters of sea ice rather than thicker sea-glacier derived ice. These inland seas, covered in a few meters of sea ice, allowing for the transmittance of light, could have provided refugia for photosynthetic eukaryotic organisms during Snowball Earth events. In order for inland seas to have remained free of sea-glacier derived ice during Snowball Earth events, passageways by which glacier ice from the ocean flowed into inland seas must have been sufficiently narrow to prevent floating sea-glaciers from flowing in, but deep enough to have allowed liquid water to flow toward the inland sea under sea-glacier ice cover. This water flow would be necessary to replace sublimation loss from the thin sea ice cover; otherwise the inland sea could dry up entirely, destroying the refugium. Using a numerical model that solves the mass and momentum conservation equations for floating ice, we explore the relationship between passageway length scale and sea-glacier thickness, in order to determine conditions under which sea-glaciers could reach the inland sea.

  13. Assessment of 137Cs and 90Sr Fluxes in the Barents Sea

    NASA Astrophysics Data System (ADS)

    Matishov, Gennady; Usiagina, Irina; Kasatkina, Nadezhda; Ilin, Gennadii

    2014-05-01

    On the basis of published and own data the annual balance of radionuclide income/outcome was assessed for 137Cs and 90Sr in the Barents Sea for the period from 1950s to the presnt. The scheme of the isotope balance calculation in the Barents Sea included the following processes:atmospheric fallout; river run-off; liquid radioactive wastes releases, income from the Norwegian and the White Seas; outflow to the adjacent areas through the Novaya Zemlya straits and the transects Svalbard-Franz Josef Land and Franz Josef Land-Novaya Zemlya; radioactive decay. According to the multiyear dynamics, the inflow of 137Cs and 90Sr to the Barents Sea was significantly preconditioned by currents from the Norwegian Sea. Three peaks of 137Cs and 90Sr isotope concentrations were registered for the surface waters on the western border of the Barents Sea. The first one was observed in the mid-1960s and was conditioned by testing of nuclear weapons. The increase of isotope concentrations in 1975 and 1980 was preconditioned by the discharge of atomic waste by the Sellafield nuclear reprocessing plant. Nowadays, after the sewage disposal plant was built, the annual discharge of nuclear waste from Sellafield plant is low. The Norwegian Sea was a major source of 137Cs and 90Sr isotope income into the Barents Sea for the period of 1960-2014. Currently, the transborder transfer of 90Sr and 137Cs from the Norwegian Sea into the Barents Sea constitutes about 99% of income for each element. Atmospheric precipitation had a major impact in the 1950-1960s after the testing of the nuclear weapons, and in 1986 after the accident at Chernobyl Nuclear Power Station. In 1963, the atmospheric precipitation of 137Cs reached 1050 TBq; and that of 90Sr, 630 TBq. In 1986, a significant amount of 137Cs inflow (up to 1010 TBq/year) was registered. The 137Cs isotope income exceeded the 90Sr income in the 1960s-1980s, and equal amounts penetrated into the Barents Sea from the Norwegian Sea in the 1990s. Before the 1990s, 137Cs inflow exceeded outflow in the annual balance, but the opposite pattern is observed nowadays. This tendency of prevailing of 137Cs outflow processes in the Barents Sea may be explained by natural decay and ecosystem self-cleaning of the radioactivity, which has penetrated previously. According to our assumptions, in total, 37400 TBq of 137Cs penetrated, and 26300 TBq of 137Cs were output from the Barents Sea during the period 1950-2010, i.e., 70.2% of this isotope was removed. From the 1960s through the present, the inflow of 90Sr exceeded the outflow. In total, 24800 TBq of 90Sr penetrated, and 19600 TBq of 90Sr were output through the northern and northeastern margins of the Barents Sea, i.e., 79.1% of this isotope was removed. From 1960 through the 1980s, the income/outcome ratio in the Barents Sea was quite stable and constituted 1.4-1.5 for 137Cs and 1.1-1.2 for 90Sr. The increase of the impact of atmospheric precipitation on 137Cs income was up to 42% in 1986 due to the Chernobyl disaster, and the income/outcome ratio increased to 2.6. The atmospheric income of 90Sr in 1986 was minor, and the ratio stayed the same for this isotope.

  14. Sea ice data for all: NSIDC's Arctic Sea Ice News & Analysis

    NASA Astrophysics Data System (ADS)

    Vizcarra, N.; Stroeve, J. C.; Serreze, M. C.; Scambos, T. A.; Meier, W.

    2014-12-01

    Arctic sea ice has long been recognized as a sensitive climate indicator and has undergone a dramatic decline over the past thirty years. The National Snow and Ice Data Center's Arctic Sea Ice News & Analysis blog continues to offer the public a transparent view of sea ice data and analysis. We have expanded our interactive sea ice graph to include Antarctic sea ice in response to increased attention from the public as a result of unexpected behavior of sea ice in the south. This poster explores the blog's new features and how other researchers, the media, and the public are currently using them.

  15. Biogeochemistry in Sea Ice: CICE model developments

    SciTech Connect

    Jeffery, Nicole; Hunke, Elizabeth; Elliott, Scott; Turner, Adrian

    2012-06-18

    Polar primary production unfolds in a dynamic sea ice environment, and the interactions of sea ice with ocean support and mediate this production. In spring, for example, fresh melt water contributes to the shoaling of the mixed layer enhancing ice edge blooms. In contrast, sea ice formation in the fall reduces light penetration to the upper ocean slowing primary production in marine waters. Polar biogeochemical modeling studies typically consider these types of ice-ocean interactions. However, sea ice itself is a biogeochemically active medium, contributing a significant and, possibly, essential source of primary production to polar regions in early spring and fall. Here we present numerical simulations using the Los Alamos Sea Ice Model (CICE) with prognostic salinity and sea ice biogeochemistry. This study investigates the relationship between sea ice multiphase physics and sea ice productivity. Of particular emphasis are the processes of gravity drainage, melt water flushing, and snow loading. During sea ice formation, desalination by gravity drainage facilitates nutrient exchange between ocean and ice maintaining ice algal blooms in early spring. Melt water flushing releases ice algae and nutrients to underlying waters limiting ice production. Finally, snow loading, particularly in the Southern Ocean, forces sea ice below the ocean surface driving an upward flow of nutrient rich water into the ice to the benefit of interior and freeboard communities. Incorporating ice microphysics in CICE has given us an important tool for assessing the importance of these processes for polar algal production at global scales.

  16. A checklist of the deep sea fishes of the Levant Sea, Mediterranean Sea.

    PubMed

    Goren, Menachem; Galil, Bella S

    2015-01-01

    We list sixty five fish species collected at depths greater than 500 m in the Levant Basin, including 10 depth records. The Levantine bathyal ichthyofauna is characterized by its eurybathy, with an upper bathymetric boundary that permitted penetration of the shallow Gibraltar and Siculo-Tunisian sills, and a much lower bathymetric boundary than recorded for conspecifics elsewhere. The opportunistic and resilient ichthyofauna re-colonized recently the deep-sea following the last anoxic event (~ 6 kyr), forming assemblages notably distinct from those in the western Mediterranean. The exploration and production of deep seabed hydrocarbons have raised the specter of severe direct impacts to the deep habitats. There is an urgent need for documenting the full extent of deep-sea biodiversity, and for providing information for the development of competent and pragmatic management plans and effective conservation policies. PMID:26250288

  17. Sea level variability of the Arabian Sea and its gulfs from tide gauges and satellite altimetry

    NASA Astrophysics Data System (ADS)

    Al-Subhi, Abdullah Mohammed

    Monthly mean sea levels in the Arabian Sea have been investigated for seasonal-to-annual variation and interannual oscillations. Relative Sea level in the Port of Aden is rising either due to the widening sea floor and/or to volume changes caused by thermal expansion. However, a correction is needed for the rate of vertical land movement. Moreover, sea level in general is responding primarily to steric height change, and is low during the late summer to autumn and high during winter to the early summer. Wavelet analysis supports the hypothesis of this study in that the interannual variation present in sea level is due to ENSO oscillations. Relative sea level at Karachi is generally rising. However, since 1960 the RSL trend is falling. Furthermore, seasonal sea level variation at Karachi differs with that in the Gulf of Aden; it is low during winter and both transition periods and high during summer in the west, while in the east it is high in mid-spring. Steric height change is also the main factor affecting sea level in the eastern Gulf of Oman and Makran coast, whereas sea level change in the northwestern part of the Gulf is due to atmospheric pressure. Wavelet transform analysis of sea level data in this area shows an anti-phase between sea level and ENSO for some years and in-phase in others. Sea level trend at Bombay revealed a small response to thermal expansion or interdecadal variability of the Monsoon. At Kandla, the sea level trend is higher than global average values due to possible tectonic activity. Sea level variation due to steric change is high in the early spring to early summer and low during the rest of the year. In contrast to the strong sea level-ENSO in-phase relationship in the Gulf of Aden, wavelet analysis of sea level along the west Indian coast shows a strong in-phase relationship with the Indian Ocean Dipole. Seasonal sea level variability in the Arabian Sea is mainly consistent with steric sea level changes except in places where the atmospheric sea level pressure plays a significant role. Interseasonal sea level variability is in phase with the monsoon seasonal changes whereas the interannual signals show evidence of El Nino/Southern Oscillation on ENSO time-scales, and the Indian Ocean Dipole on decadal time-scales. Century-scale relative sea level trends more or less agree with global averages, but are very site specific and are undoubtedly affected by vertical land motion either from natural or anthropogenic causes.

  18. Microplastic pollution in deep-sea sediments.

    PubMed

    Van Cauwenberghe, Lisbeth; Vanreusel, Ann; Mees, Jan; Janssen, Colin R

    2013-11-01

    Microplastics are small plastic particles (<1 mm) originating from the degradation of larger plastic debris. These microplastics have been accumulating in the marine environment for decades and have been detected throughout the water column and in sublittoral and beach sediments worldwide. However, up to now, it has never been established whether microplastic presence in sediments is limited to accumulation hot spots such as the continental shelf, or whether they are also present in deep-sea sediments. Here we show, for the first time ever, that microplastics have indeed reached the most remote of marine environments: the deep sea. We found plastic particles sized in the micrometre range in deep-sea sediments collected at four locations representing different deep-sea habitats ranging in depth from 1100 to 5000 m. Our results demonstrate that microplastic pollution has spread throughout the world's seas and oceans, into the remote and largely unknown deep sea. PMID:24035457

  19. Physics of the nucleon sea quark distributions

    SciTech Connect

    Vogt, R.

    2000-03-10

    Sea quark distributions in the nucleon have naively been expected to be generated perturbatively by gluon splitting. In this case, there is no reason for the light quark and anti-quark sea distributions to be different. No asymmetries in the strange or heavy quark sea distributions are predicted in the improved parton model. However,recent experiments have called these naive expectations into question. A violation of the Gottfried sum rule has been measured in several experiments, suggesting that (bar u) < (bar d) in the proton. Additionally, other measurements, while not definitive, show that there may be an asymmetry in the strange and anti-strange quark sea distributions. These effects may require nonperturbative explanations. In this review we first discuss the perturbative aspects of the sea quark distributions. We then describe the experiments that could point to nonperturbative contributions to the nucleon sea. Current phenomenological models that could explain some of these effects are reviewed.

  20. Skillful prediction of Barents Sea ice cover

    NASA Astrophysics Data System (ADS)

    Onarheim, Ingrid H.; Eldevik, Tor; Årthun, Marius; Ingvaldsen, Randi B.; Smedsrud, Lars H.

    2015-07-01

    A main concern of present climate change is the Arctic sea ice cover. In wintertime, its observed variability is largely carried by the Barents Sea. Here we propose and evaluate a simple quantitative and prognostic framework based on first principles and rooted in observations to predict the annual mean Barents Sea ice cover, which variance is carried by the winter ice (96%). By using observed ocean heat transport and sea ice area, the proposed framework appears skillful and explains 50% of the observed sea ice variance up to 2 years in advance. The qualitative prediction of increase versus decrease in ice cover is correct 88% of the time. Model imperfections can largely be diagnosed from simultaneous meridional winds. The framework and skill are supported by a 60 year simulation from a regional ice-ocean model. We particularly predict that the winter sea ice cover for 2016 will be slightly less than 2015.

  1. Sea level anomalies exacerbate beach erosion

    NASA Astrophysics Data System (ADS)

    Theuerkauf, Ethan J.; Rodriguez, Antonio B.; Fegley, Stephen R.; Luettich, Richard A.

    2014-07-01

    Sea level anomalies are intra-seasonal increases in water level forced by meteorological and oceanographic processes unrelated to storms. The effects of sea level anomalies on beach morphology are unknown but important to constrain because these events have been recognized over large stretches of continental margins. Here, we present beach erosion measurements along Onslow Beach, a barrier island on the U.S. East Coast, in response to a year with frequent sea level anomalies and no major storms. The anomalies enabled extensive erosion, which was similar and in most places greater than the erosion that occurred during a year with a hurricane. These results highlight the importance of sea level anomalies in facilitating coastal erosion and advocate for their inclusion in beach-erosion models and management plans. Sea level anomalies amplify the erosive effects of accelerated sea level rise and changes in storminess associated with global climate change.

  2. Early Pliocene Nordic Seas Palaeoceanography - Relation with Ocean Gateways

    NASA Astrophysics Data System (ADS)

    De Schepper, S.; Schreck, M.; Beck, K. M.; Mangerud, G.; Matthiessen, J. J.; Risebrobakken, B.

    2014-12-01

    In the northern high latitude oceans, organic-walled phytoplankton is often the only microfossil group present in the sediment record that can be used for palaeoceanographic and palaeoenvironmental studies. Recently collected dinoflagellate cyst and acritarch records from the Norwegian and Iceland Seas reveal a wide-scale, major assemblage turnover including extinction of several taxa, disappearance of heterotrophic species and decrease in productivity around 4.5 Ma. These changes can most likely be attributed to a reorganization of the ocean circulation and can be interpreted as the establishment of a more modern-like Norwegian Atlantic Current and proto-East Greenland Current. The timing at around 4.5 Ma corresponds favorably to the shoaling of the Central American Seaway and northward flow of Pacific water via the Bering Strait into the North Atlantic, the latter being evidenced by the first arrival of Pacific molluscs in the Iceland (Tjörnes section). The changes in ocean circulation are not restricted to the Nordic Seas, with increased sediment accumulation at several North Atlantic drifts (e.g. Gloria and Eirik drifts) also illustrating important changes in the North Atlantic deep-water circulation.

  3. Sea otter health: Challenging a pet hypothesis.

    PubMed

    Lafferty, Kevin D

    2015-12-01

    A recent series of studies on tagged sea otters (Enhydra lutris nereis) challenges the hypothesis that sea otters are sentinels of a dirty ocean, in particular, that pet cats are the main source of exposure to Toxoplasma gondii in central California. Counter to expectations, sea otters from unpopulated stretches of coastline are less healthy and more exposed to parasites than city-associated otters. Ironically, now it seems that spillover from wildlife, not pets, dominates spatial patterns of disease transmission. PMID:26155464

  4. Sea otter health: Challenging a pet hypothesis

    PubMed Central

    Lafferty, Kevin D.

    2015-01-01

    A recent series of studies on tagged sea otters (Enhydra lutris nereis) challenges the hypothesis that sea otters are sentinels of a dirty ocean, in particular, that pet cats are the main source of exposure to Toxoplasma gondii in central California. Counter to expectations, sea otters from unpopulated stretches of coastline are less healthy and more exposed to parasites than city-associated otters. Ironically, now it seems that spillover from wildlife, not pets, dominates spatial patterns of disease transmission. PMID:26155464

  5. The International Arctic Seas Assessment Project

    SciTech Connect

    Linsley, G.S.; Sjoeblom, K.L.

    1994-07-01

    The International Arctic Seas Assessment Project (IASAP) was initiated in 1993 to address widespread concern over the possible health and environmental impacts associated with the radioactive waste dumped into the shallow waters of the Arctic Seas. This article discusses the project with these general topics: A brief history of dumping activities; the international control system; perspectives on arctic Seas dumping; the IASAP aims and implementation; the IASAP work plan and progress. 2 figs.

  6. Sea Surface Salinity : Research Challenges and Opportunities

    NASA Technical Reports Server (NTRS)

    Halpern, David; Lagerloef, Gary; Font, Jordi

    2012-01-01

    Sea surface salinity (SSS) can be important in regulating sea surface temperature (SST). Two technological breakthrough satellite SSS missions, Aquarius and Soil Moisture and Ocean Salinity (SMOS), are currently producing high-quality SSS data. This paper provides an overview of the importance of SSS for weather and climate applications and describes the Aquarius and SMOS missions. The newness of adequately sampled SSS data prompted a first-time at-sea field campaign devoted to improved understanding of SSS variations.

  7. Scientific reticence and sea level rise

    NASA Astrophysics Data System (ADS)

    Hansen, J. E.

    2007-04-01

    I suggest that a 'scientific reticence' is inhibiting the communication of a threat of a potentially large sea level rise. Delay is dangerous because of system inertias that could create a situation with future sea level changes out of our control. I argue for calling together a panel of scientific leaders to hear evidence and issue a prompt plain-written report on current understanding of the sea level change issue.

  8. Lena River Delta and East Siberian Sea

    NASA Technical Reports Server (NTRS)

    2002-01-01

    The winter sea ice in the east Siberian Sea is looking a bit like a cracked windshield in these true-color Moderate Resolution Imaging Spectroradiometer (MODIS) images from June 16 and 23, 2002. North of the thawing tundra, the sea ice takes on its cracked, bright blue appearance as it thins, which allows the reflection of the water to show through. Numerous still-frozen lakes dot the tundra. Credit: Jacques Descloitres, MODIS Land Rapid Response Team, NASA/GSFC

  9. Sea otter health: challenging a pet hypothesis

    USGS Publications Warehouse

    Lafferty, Kevin D.

    2015-01-01

    A recent series of studies on tagged sea otters (Enhydra lutris nereis) challenges the hypothesis that sea otters are sentinels of a dirty ocean, in particular, that pet cats are the main source of exposure to Toxoplasma gondii in central California. Counter to expectations, sea otters from unpopulated stretches of coastline are less healthy and more exposed to parasites than city-associated otters. Ironically, now it seems that spillover from wildlife, not pets, dominates spatial patterns of disease transmission.

  10. SeaWiFS: Summer in Antarctica

    NASA Technical Reports Server (NTRS)

    2002-01-01

    The Ross Sea has been somewhat cloud free lately, providing SeaWiFS with views such as this one from December 26, 2001. Note the deep green water; this is a highly productive part of the world'd oceans. Also note the ice gathered around McMurdo Sound. The ice is making it difficult for penguins to reach their food supply. Credit: Provided by the SeaWiFS Project, NASA/Goddard Space Flight Center, and ORBIMAGE

  11. Impact of sea ice initialization on sea ice and atmosphere prediction skill on seasonal timescales

    NASA Astrophysics Data System (ADS)

    Guemas, V.; Chevallier, M.; Déqué, M.; Bellprat, O.; Doblas-Reyes, F.

    2016-04-01

    We present a robust assessment of the impact of sea ice initialization from reconstructions of the real state on the sea ice and atmosphere prediction skill. We ran two ensemble seasonal prediction experiments from 1979 to 2012 : one using realistic sea ice initial conditions and another where sea ice is initialized from a climatology, with two forecast systems. During the melting season in the Arctic Ocean, sea ice forecasts become skilful with sea ice initialization until 3-5 months ahead, thanks to the memory held by sea ice thickness. During the freezing season in both the Arctic and Antarctic Oceans, sea ice forecasts are skilful for 7 and 2 months, respectively, with negligible differences between the two experiments, the memory being held by the ocean heat content. A weak impact on the atmosphere prediction skill is obtained.

  12. Sea Ice Entrainment and Sediment Sources

    NASA Astrophysics Data System (ADS)

    Miles, S.; Darby, D. A.; Jakobsson, M.; Rigor, I.

    2007-12-01

    More than 20 sea ice sediment samples collected during the Healy-Oden Trans-Arctic Expedition (HOTRAX-'05) and the Lomonosov Ridge off Greenland Expedition (LOMROG-'07) along with 18 dirty ice samples from previous expeditions back to the early 1970's show a consistent trend of several sources especially the Laptev and Kara Seas and northern Canada. Modern sea ice back-trajectories from the coordinates of the dirty sea ice samples using past drifts of this ice from the International Buoy Drift Program indicate a close match to the Fe grain sources. Comparison with several sediment cores from across the Arctic and in Fram Strait indicate that Holocene sediment that is primarily transported by sea ice contains the same sources based on Fe oxide grain chemical fingerprint matches with circum-Arctic source areas previously characterized. Observations of encounters with dirty ice by HOTRAX and LOMROG icebreaker expeditions indicate that while a small percentage of sea ice contains sediment, this dirty ice is concentrated in bands extending several kilometers and consisting of irregularly spaced patches of dirty ice that are usually less than a 100 meters in width. Also, sea ice containing coarse sediment and/or large shells due to anchor ice are less than 10 percent of dirty sea ice but that they may contain much higher concentrations of sediment than sea ice containing finer sediment from suspension freezing.

  13. Coastal eolian landforms and sea level fluctuations

    NASA Astrophysics Data System (ADS)

    Badyukova, E. N.; Solovieva, G. D.

    2015-02-01

    This paper is dedicated to correlation of the formation of coastal marine landforms with sea level fluctuations and climate changes in the last millennium using the southeastern Baltic region as an example. The morphological analysis of spits and historical evidence reveal three sea level oscillations in its evolution. It is shown that the sea level rise against the background of the sandy material excess in the coastal zone and optimum angle of the prevailing land-directed wind are the main factors responsible for accumulation of the thickest sandy formations. The recent climate warming and related sea level rise provoke global destabilization of coastal dune massifs.

  14. Population status of California sea otters

    SciTech Connect

    Not Available

    1988-11-30

    The main objective of the study was to develop a simulation model to facilitate analysis of the risk of oil spills to the threatened California sea otter population. Existing data on the dynamics and demography of the population were synthesized. The additional data needed for model development were collected through radiotelemetry studies of sea otters in Alaska and California. The simulation model contains four interrelated stochastic submodels: a short-term population model, a long-term population model, a sea otter distribution model, and a sea otter movement model. The report includes a detailed description of the model, the data on which it is based, and an operating manual.

  15. Context awareness and sensitivity in SEA implementation

    SciTech Connect

    Hilding-Rydevik, Tuija Bjarnadottir, Holmfridur

    2007-10-15

    The Impact Assessment research community repeatedly asserts that the implementation of Strategic Environmental Assessment (SEA) should take the issue of context into consideration. The primary aim of this paper then is to attempt to give substance to the concept of 'context' in relation to the implementation of SEA. The second aim is to discuss the relevance of context consciousness and sensitivity in relation to one of the main aims given to SEA implementation i.e. to contribute to the 'integration' of environmental perspectives in planning processes. Context must be defined in relation to a certain question. In this paper the question in focus is the assumption that SEA implementation will contribute to integration of environmental issues in planning processes. Research results relating to the use of environmental tools, like for example SEA, and experiences of integration efforts, strongly indicate that the use of a single tool like SEA is not enough to achieve this integration. The current 'context free' normative and procedural assumptions concerning the aim of SEA implementation and 'best practice' in term of SEA can be criticised on the same grounds as normative and procedural planning theories, as being context free. The assumptions behind the current formulations of the aim and best practice of SEA need to be revisited. A firm empirical and theoretical knowledge and discussion is needed, especially in relation to the issue of context and integration. This paper provides a starting point in this direction.

  16. Dynamic Singularity Spectrum Distribution of Sea Clutter

    NASA Astrophysics Data System (ADS)

    Xiong, Gang; Yu, Wenxian; Zhang, Shuning

    2015-12-01

    The fractal and multifractal theory have provided new approaches for radar signal processing and target-detecting under the background of ocean. However, the related research mainly focuses on fractal dimension or multifractal spectrum (MFS) of sea clutter. In this paper, a new dynamic singularity analysis method of sea clutter using MFS distribution is developed, based on moving detrending analysis (DMA-MFSD). Theoretically, we introduce the time information by using cyclic auto-correlation of sea clutter. For transient correlation series, the instantaneous singularity spectrum based on multifractal detrending moving analysis (MF-DMA) algorithm is calculated, and the dynamic singularity spectrum distribution of sea clutter is acquired. In addition, we analyze the time-varying singularity exponent ranges and maximum position function in DMA-MFSD of sea clutter. For the real sea clutter data, we analyze the dynamic singularity spectrum distribution of real sea clutter in level III sea state, and conclude that the radar sea clutter has the non-stationary and time-varying scale characteristic and represents the time-varying singularity spectrum distribution based on the proposed DMA-MFSD method. The DMA-MFSD will also provide reference for nonlinear dynamics and multifractal signal processing.

  17. Parasites in the Wadden Sea food web

    NASA Astrophysics Data System (ADS)

    Thieltges, David W.; Engelsma, Marc Y.; Wendling, Carolin C.; Wegner, K. Mathias

    2013-09-01

    While the free-living fauna of the Wadden Sea has received much interest, little is known on the distribution and effects of parasites in the Wadden Sea food web. However, recent studies on this special type of trophic interaction indicate a high diversity of parasites in the Wadden Sea and suggest a multitude of effects on the hosts. This also includes effects on specific predator-prey relationships and the general structure of the food web. Focussing on molluscs, a major group in the Wadden Sea in terms of biomass and abundance and an important link between primary producers and predators, we review existing studies and exemplify the ecological role of parasites in the Wadden Sea food web. First, we give a brief inventory of parasites occurring in the Wadden Sea, ranging from microparasites (e.g. protozoa, bacteria) to macroparasites (e.g. helminths, parasitic copepods) and discuss the effects of spatial scale on heterogeneities in infection levels. We then demonstrate how parasites can affect host population dynamics by acting as a strong mortality factor, causing mollusc mass mortalities. In addition, we will exemplify how parasites can mediate the interaction strength of predator-prey relationships and affect the topological structure of the Wadden Sea food web as a whole. Finally, we highlight some ongoing changes regarding parasitism in the Wadden Sea in the course of global change (e.g. species introduction, climate change) and identify important future research questions to entangle the role of parasites in the Wadden Sea food web.

  18. Sonmicat: Sea Level Observation System of Catalonia

    NASA Astrophysics Data System (ADS)

    Martinez-Benjamin, J. J.; Termens, A.; Ruiz, A.; Gonzalez Lopez, S.

    2014-12-01

    SONMICAT is the integrated sea level observation system of Catalonia. SONMICAT aims at providing high-quality continous measurements of sea- and land levels at the Catalan coast from tide gauges (relative sea levels) and from modern geodetic techniques (vertical land motion and absolute sea levels) for studies on long-term sea level trends, but also the calibration of satellite altimeters, for instance. This synergy is indeed the only way to get a clear and unambigous picture of what is actually going on at the coast of Catalonia. SONMICAT aims to be: - an integrated sea level monitoring system (different types of data, sources, time and space scales), - a sea level information system handling the data measured by different observation networks, - a local/regional component of international sea level observing systems (GLOSS, ESEAS, etc.), and - a local/regional interface for related European and Global projects and databases (PSML, TIGA, etc.) There is a gap of sea level data (GLOSS, PSML, TIGA) in the coast of Catalonia, although several groups and institutions have started to do some work. SONMICAT will fill it. Up to now, the system has started at l'Estartit and Barcelona harbours. A description of the actual SONMICAT infraestructure and campaigns - especially at Barcelona harbour - are presented. In June 2014, an airborne LiDAR campaign has been carrying on in Barcelona following two ICESat tracks. First results of the airborne survey will also be presented.

  19. Sea level rise and its coastal impacts

    NASA Astrophysics Data System (ADS)

    Cazenave, Anny; Cozannet, Gonéri Le

    2014-02-01

    Global warming in response to accumulation of human-induced greenhouse gases inside the atmosphere has already caused several visible consequences, among them increase of the Earth's mean temperature and ocean heat content, melting of glaciers, and loss of ice from the Greenland and Antarctica ice sheets. Ocean warming and land ice melt in turn are causing sea level to rise. Sea level rise and its impacts on coastal zones have become a question of growing interest in the scientific community, as well as in the media and public. In this review paper, we summarize the most up-to-date knowledge about sea level rise and its causes, highlighting the regional variability that superimposes the global mean rise. We also present sea level projections for the 21st century under different warming scenarios. We next address the issue of the sea level rise impacts. We question whether there is already observational evidence of coastal impacts of sea level rise and highlight the fact that results differ from one location to another. This suggests that the response of coastal systems to sea level rise is highly dependent on local natural and human settings. We finally show that in spite of remaining uncertainties about future sea levels and related impacts, it becomes possible to provide preliminary assessment of regional impacts of sea level rise.

  20. The role of sea ice dynamics in global climate change

    NASA Technical Reports Server (NTRS)

    Hibler, William D., III

    1992-01-01

    The topics covered include the following: general characteristics of sea ice drift; sea ice rheology; ice thickness distribution; sea ice thermodynamic models; equilibrium thermodynamic models; effect of internal brine pockets and snow cover; model simulations of Arctic Sea ice; and sensitivity of sea ice models to climate change.

  1. Introduction to the petroleum geology of the North Sea

    SciTech Connect

    Glennie, K.W.

    1984-01-01

    This book presents papers on North Sea oil and gas deposits. Topics considered include North Sea exploration from 1964-1983, the structural framework and the pre-Permian history of the North Sea area, the late Permian period, the Triassic period, the Jurasic period, the Cretaceous period, the Cenozoic era, source rocks of the North Sea, and North Sea hydrocarbon plays.

  2. Marine environments in the China Seas and their prediction

    SciTech Connect

    Bao, C.

    1993-12-31

    The China Seas surround the China continent to its south and east, and connect with the Pacific Ocean. In this paper, marine environmental elements in the China Seas such as marine climate, storm surge, sea wave, sea temperature, sea ice, tsunami and red tide, are analyzed. The predication of marine environments, especially oceanic disasters with good accuracy are also given in this paper.

  3. Diseases in North Sea fishes

    NASA Astrophysics Data System (ADS)

    Dethlefsen, V.

    1984-03-01

    Prior to the studies reviewed here, only lymphocystis and skeletal deformities of a variety of fish species and certain diseases of eel were known to occur in the German Bight (North Sea). From 1977 until now, 9 externally visible lesions on North Sea fishes were observed; in addition to those mentioned before, they comprise: fin rot, ulcerations, epidermal papilloma, hyperplasia, pseudobranchial tumour, eye diseases and gill swellings. With the exception of information on changes in frequencies of vertebral deformities of herring from the 1950's to the 1970's, there are no long-term data characterizing changes in frequencies of the diseases under study. For pseudobranchial tumours of cod and epidermal papilloma of dab, information is provided on occurrence and abundance. The distribution pattern of cod afflicted with pseudobranchial tumours is strongly influenced by the migratory behaviour of the fish. Epidermal papillomas of dab were more frequently found at stations within the inner German Bight than in neighbouring areas. The Bight is used for dumping of wastes from titaniumdioxide production. Further disease hot spots are areas off the Humber estuary and the British coast. Analysis of chromium in dab from the German Bight revealed elevated concentrations in epidermal tissues of specimens from the dumping area compared with that found in dab from neighbouring localities. Particulate iron was demonstrated to occur in mucous cells of dab from the dumping area. From increased levels of heavy metals with cancerogenic potential in sensitive target tissues and from increased prevalences of diseased fish in the dumping area it is concluded that these phenomena are possibly causally linked. In the vicinity of the Humber estuary high disease rates were encountered and areas with high prevalences of dab afflicted with epidermal papilloma extended over regions shown to be transport routes for persistent pollutants such as radioactive materials. It is therefore suggested that the long-range distribution of fish diseases in the southern North Sea might reflect the long-range transport of persistent pollutants.

  4. Uncertainty estimation for operational ocean forecast products—a multi-model ensemble for the North Sea and the Baltic Sea

    NASA Astrophysics Data System (ADS)

    Golbeck, Inga; Li, Xin; Janssen, Frank; Brüning, Thorger; Nielsen, Jacob W.; Huess, Vibeke; Söderkvist, Johan; Büchmann, Bjarne; Siiriä, Simo-Matti; Vähä-Piikkiö, Olga; Hackett, Bruce; Kristensen, Nils M.; Engedahl, Harald; Blockley, Ed; Sellar, Alistair; Lagemaa, Priidik; Ozer, Jose; Legrand, Sebastien; Ljungemyr, Patrik; Axell, Lars

    2015-12-01

    Multi-model ensembles for sea surface temperature (SST), sea surface salinity (SSS), sea surface currents (SSC), and water transports have been developed for the North Sea and the Baltic Sea using outputs from several operational ocean forecasting models provided by different institutes. The individual models differ in model code, resolution, boundary conditions, atmospheric forcing, and data assimilation. The ensembles are produced on a daily basis. Daily statistics are calculated for each parameter giving information about the spread of the forecasts with standard deviation, ensemble mean and median, and coefficient of variation. High forecast uncertainty, i.e., for SSS and SSC, was found in the Skagerrak, Kattegat (Transition Area between North Sea and Baltic Sea), and the Norwegian Channel. Based on the data collected, longer-term statistical analyses have been done, such as a comparison with satellite data for SST and evaluation of the deviation between forecasts in temporal and spatial scale. Regions of high forecast uncertainty for SSS and SSC have been detected in the Transition Area and the Norwegian Channel where a large spread between the models might evolve due to differences in simulating the frontal structures and their movements. A distinct seasonal pattern could be distinguished for SST with high uncertainty between the forecasts during summer. Forecasts with relatively high deviation from the multi-model ensemble (MME) products or the other individual forecasts were detected for each region and each parameter. The comparison with satellite data showed that the error of the MME products is lowest compared to those of the ensemble members.

  5. Advanced deep sea diving equipment

    NASA Technical Reports Server (NTRS)

    Danesi, W. A.

    1972-01-01

    Design requirements are generated for a deep sea heavy duty diving system to equip salvage divers with equipment and tools that permit work of the same quality and in times approaching that done on the surface. The system consists of a helmet, a recirculator for removing carbon dioxide, and the diver's dress. The diver controls the inlet flow by the recirculatory control valve and is able to change closed cycle operation to open cycle if malfunction occurs. Proper function of the scrubber in the recirculator minimizes temperature and humidity effects as it filters the returning air.

  6. UN adopts Law of Sea

    NASA Astrophysics Data System (ADS)

    Richman, Barbara T.

    After more than 8 years of diplomatic wrangling, the United Nations Convention on the Law of the Sea was adopted on April 30 by a vote of 130 to 4. The United States, Israel, Turkey, and Venezuela voted against the treaty; 17 nations—including the Soviet Union, West Germany, and Britain—abstained.The treaty, which would give nations the exclusive rights to natural resources in the continental shelf up to approximately 650 km offshore, will be signed in December. The treaty becomes effective 1 year after at least 60 nations ratify it.

  7. Unlocking a Sea Ice Secret

    SciTech Connect

    Dr. Rachel Obbard

    2013-04-22

    Dr. Rachel Obbard and her research group from Dartmouth College traveled to the Antarctic to collect samples of sea ice. Next stop: the GeoSoilEnviroCARS x-ray beamline at the Advanced Photon Source at Argonne National Laboratory in Illinois. This U.S. Department of Energy Office of Science synchrotron x-ray research facility gave the Obbard team the frontier scientific tools they needed to study the path bromide takes as it travels from the ocean to the atmosphere.

  8. 50 CFR 648.11 - At-sea sea sampler/observer coverage.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... Register citations affecting § 648.11, see the List of CFR Sections Affected, which appears in the Finding... Atlantic deep-sea red crab; or a moratorium permit for summer flounder; to carry a NMFS-certified fisheries... Atlantic deep-sea red crab permit, a skate permit, or a tilefish permit, if requested by the sea...

  9. 50 CFR 648.11 - At-sea sea sampler/observer coverage.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... Register citations affecting § 648.11, see the List of CFR Sections Affected, which appears in the Finding... Atlantic deep-sea red crab; or a moratorium permit for summer flounder; to carry a NMFS-certified fisheries... Atlantic deep-sea red crab permit, a skate permit, or a tilefish permit, if requested by the sea...

  10. 50 CFR 648.11 - At-sea sea sampler/observer coverage.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... the List of CFR Sections Affected, which appears in the Finding Aids section of the printed volume and... Atlantic deep-sea red crab; or a moratorium permit for summer flounder; to carry a NMFS-certified fisheries... Atlantic deep-sea red crab permit, a skate permit, or a tilefish permit, if requested by the sea...

  11. Bayesian Hierarchical Air-Sea Interaction Modeling: Application to the Labrador Sea

    NASA Technical Reports Server (NTRS)

    Niiler, Pearn P.

    2002-01-01

    The objectives are to: 1) Organize data from 26 MINIMET drifters in the Labrador Sea, including sensor calibration and error checking of ARGOS transmissions. 2) Produce wind direction, barometer, and sea surface temperature time series. In addition, provide data from historical file of 150 SHARP drifters in the Labrador Sea. 3) Work with data interpretation and data-modeling assimilation issues.

  12. On the flow of Atlantic water and temperature anomalies in the Nordic Seas toward the Arctic Ocean

    NASA Astrophysics Data System (ADS)

    Chafik, L.; Nilsson, J.; Skagseth, Å.; Lundberg, P.

    2015-12-01

    The climatic conditions over the Arctic Ocean are strongly influenced by the inflow of warm Atlantic water conveyed by the Norwegian Atlantic Slope Current (NwASC). Based on sea surface height (SSH) data from altimetry, we develop a simple dynamical measure of the NwASC transport to diagnose its spatio-temporal variability. This supports a dynamical division of the NwASC into two flow regimes; the Svinøy Branch (SvB) in the southern Norwegian Sea, and the Fram Strait Branch (FSB) west of Spitsbergen. The SvB transport is well correlated with the SSH and atmospheric variability within the Nordic Seas, factors that also affect the inflow to the Barents Sea. In contrast, the FSB is influenced by regional atmospheric conditions around Svalbard and northern Barents Sea. Using a composite analysis, we further relate anomalous strong SvB flow events to temperature fluctuations along the core of Atlantic water. A warm composite anomaly is found to propagate northward, with a tendency to amplify enroute, after these events. A roughly 12 months delayed temperature signal is identified in the FSB. However, also in the Lofoten Basin interior a delayed temperature signal is found, which appears to originate from the NwASC. This study suggests that hydrographic anomalies both upstream from the North Atlantic, and locally generated in the Norwegian Sea, are important for the oceanic heat and salt transport that eventually enters into the Arctic.

  13. Sea lice as a density-dependent constraint to salmonid farming

    PubMed Central

    Jansen, Peder A.; Kristoffersen, Anja B.; Viljugrein, Hildegunn; Jimenez, Daniel; Aldrin, Magne; Stien, Audun

    2012-01-01

    Fisheries catches worldwide have shown no increase over the last two decades, while aquaculture has been booming. To cover the demand for fish in the growing human population, continued high growth rates in aquaculture are needed. A potential constraint to such growth is infectious diseases, as disease transmission rates are expected to increase with increasing densities of farmed fish. Using an extensive dataset from all farms growing salmonids along the Norwegian coast, we document that densities of farmed salmonids surrounding individual farms have a strong effect on farm levels of parasitic sea lice and efforts to control sea lice infections. Furthermore, increased intervention efforts have been unsuccessful in controlling elevated infection levels in high salmonid density areas in 2009–2010. Our results emphasize host density effects of farmed salmonids on the population dynamics of sea lice and suggest that parasitic sea lice represent a potent negative feedback mechanism that may limit sustainable spatial densities of farmed salmonids. PMID:22319130

  14. 50 CFR Appendix F to Part 622 - Specifications for Sea Turtle Mitigation Gear and Sea Turtle Handling and Release Requirements

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 50 Wildlife and Fisheries 12 2012-10-01 2012-10-01 false Specifications for Sea Turtle Mitigation Gear and Sea Turtle Handling and Release Requirements F Appendix F to Part 622 Wildlife and Fisheries...—Specifications for Sea Turtle Mitigation Gear and Sea Turtle Handling and Release Requirements A. Sea...

  15. Amundsen Sea ice production and transport

    NASA Astrophysics Data System (ADS)

    Assmann, Karen M.; Hellmer, Hartmut H.; Jacobs, Stanley S.

    2005-12-01

    Drift and variability of sea ice in the Amundsen Sea are investigated with ice buoys deployed in March 2000 and a coupled ice-ocean model. The Bremerhaven Regional Ice Ocean Simulations (BRIOS) model results are compared with in situ ocean, atmosphere, and sea ice measurements; satellite observations; and 8-19 months of buoy drift data. We identify a zone of coastal westward drift and a band of faster eastward drift, separated by a broad transition region characterized by variable ice motions. The model represents drift events at scales approaching its resolution but is limited at smaller scales and by deficiencies in the National Centers for Environmental Prediction forcing. Two thirds of the modeled ice production in the southern Amundsen moves westward near the coast, its transport modulated by meridional wind strength, damping sea ice formation in the eastern Ross Sea. Half of the ice exported from the Ross moves eastward into the northern Amundsen Sea, a net sea ice sink that also receives more than one third of the ice generated to its south. A low rate of exchange occurs with the Bellingshausen Sea, which must have a more independent ice regime. Snow ice formation resulting from high precipitation accounts for one quarter of the ice volume in the Amundsen Sea, aiding the formation of thick ice in a region with generally divergent ice drift. Freshwater extraction by sea ice formation is roughly balanced by precipitation and ice shelf melting, but a positive trend in the surface flux is consistent with an Amundsen source for reported freshening in the Ross Sea.

  16. Processes driving sea ice variability in the Bering Sea in an eddying ocean/sea ice model: Mean seasonal cycle

    NASA Astrophysics Data System (ADS)

    Li, Linghan; McClean, Julie L.; Miller, Arthur J.; Eisenman, Ian; Hendershott, Myrl C.; Papadopoulos, Caroline A.

    2014-12-01

    The seasonal cycle of sea ice variability in the Bering Sea, together with the thermodynamic and dynamic processes that control it, are examined in a fine resolution (1/10°) global coupled ocean/sea-ice model configured in the Community Earth System Model (CESM) framework. The ocean/sea-ice model consists of the Los Alamos National Laboratory Parallel Ocean Program (POP) and the Los Alamos Sea Ice Model (CICE). The model was forced with time-varying reanalysis atmospheric forcing for the time period 1970-1989. This study focuses on the time period 1980-1989. The simulated seasonal-mean fields of sea ice concentration strongly resemble satellite-derived observations, as quantified by root-mean-square errors and pattern correlation coefficients. The sea ice energy budget reveals that the seasonal thermodynamic ice volume changes are dominated by the surface energy flux between the atmosphere and the ice in the northern region and by heat flux from the ocean to the ice along the southern ice edge, especially on the western side. The sea ice force balance analysis shows that sea ice motion is largely associated with wind stress. The force due to divergence of the internal ice stress tensor is large near the land boundaries in the north, and it is small in the central and southern ice-covered region. During winter, which dominates the annual mean, it is found that the simulated sea ice was mainly formed in the northern Bering Sea, with the maximum ice growth rate occurring along the coast due to cold air from northerly winds and ice motion away from the coast. South of St Lawrence Island, winds drive the model sea ice southwestward from the north to the southwestern part of the ice-covered region. Along the ice edge in the western Bering Sea, model sea ice is melted by warm ocean water, which is carried by the simulated Bering Slope Current flowing to the northwest, resulting in the S-shaped asymmetric ice edge. In spring and fall, similar thermodynamic and dynamic patterns occur in the model, but with typically smaller magnitudes and with season-specific geographical and directional differences.

  17. The Barents and Chukchi Seas: Comparison of two Arctic shelf ecosystems

    NASA Astrophysics Data System (ADS)

    Hunt, George L.; Blanchard, Arny L.; Boveng, Peter; Dalpadado, Padmini; Drinkwater, Kenneth F.; Eisner, Lisa; Hopcroft, Russ R.; Kovacs, Kit M.; Norcross, Brenda L.; Renaud, Paul; Reigstad, Marit; Renner, Martin; Skjoldal, Hein Rune; Whitehouse, Andy; Woodgate, Rebecca A.

    2013-01-01

    This paper compares and contrasts the ecosystems of the Barents and Chukchi Seas. Despite their similarity in a number of features, the Barents Sea supports a vast biomass of commercially important fish, but the Chukchi does not. Here we examine a number of aspects of these two seas to ascertain how they are similar and how they differ. We then indentify processes and mechanisms that may be responsible for their similarities and differences. Both the Barents and Chukchi Seas are high latitude, seasonally ice covered, Arctic shelf-seas. Both have strongly advective regimes, and receive water from the south. Water entering the Barents comes from the deep, ice-free and "warm" Norwegian Sea, and contains not only heat, but also a rich supply of zooplankton that supports larval fish in spring. In contrast, Bering Sea water entering the Chukchi in spring and early summer is cold. In spring, this Bering Sea water is depleted of large, lipid-rich zooplankton, thus likely resulting in a relatively low availability of zooplankton for fish. Although primary production on average is similar in the two seas, fish biomass density is an order of magnitude greater in the Barents than in the Chukchi Sea. The Barents Sea supports immense fisheries, whereas the Chukchi Sea does not. The density of cetaceans in the Barents Sea is about double that in the Chukchi Sea, as is the density of nesting seabirds, whereas, the density of pinnipeds in the Chukchi is about double that in the Barents Sea. In the Chukchi Sea, export of carbon to the benthos and benthic biomass may be greater. We hypothesize that the difference in fish abundance in the two seas is driven by differences in the heat and plankton advected into them, and the amount of primary production consumed in the upper water column. However, we suggest that the critical difference between the Chukchi and Barents Seas is the pre-cooled water entering the Chukchi Sea from the south. This cold water, and the winter mixing of the Chukchi Sea as it becomes ice covered, result in water temperatures below the physiological limits of the commercially valuable fish that thrive in the southeastern Bering Sea. If climate change warms the Barents Sea, thereby increasing the open water area via reducing ice cover, productivity at most trophic levels is likely to increase. In the Chukchi, warming should also reduce sea ice cover, permitting a longer production season. However, the shallow northern Bering and Chukchi Seas are expected to continue to be ice-covered in winter, so water there will continue to be cold in winter and spring, and is likely to continue to be a barrier to the movement of temperate fish into the Chukchi Sea. Thus, it is unlikely that large populations of boreal fish species will become established in this Arctic marginal sea.

  18. Seasonal gyres in shelf seas

    NASA Astrophysics Data System (ADS)

    Hill, A. E.

    1993-12-01

    Attention is drawn to the existence of stably located, seasonal, baroclinic gyres in shelf seas. During summer each year surface heating over isolated regions of weak tidal stirring, such as topographic depressions, can lead to the formation of domes of cold, dense bottom water trapped beneath the thermocline. The dense water dome is isolated horizontally from adjacent water by bottom fronts which drive a cyclonic, near-surface circulation around the dome. There is clear evidence for the existence of such a seasonal cyclonic gyre in the western Irish Sea and there are at least five other locations on the northwest European shelf where similar structures may be found. Although the existence of summer cyclonic gyres can be understood in terms of relatively simple dynamics, their significance is not widely appreciated. They form a component of the organized, mesoscale circulation on continental shelves, they may be important retention sites for marine plankton and their simulation represents a crucial test for the performance of three-dimensional shelf circulation models.

  19. Denitrification in the Arabian Sea

    NASA Astrophysics Data System (ADS)

    Naqvi, S. Wajih A.; Noronha, Ronald J.; Reddy, C. V. Gangadhara

    1982-04-01

    Estimates of the amount of denitrification in the Arabian Sea are inconsistent, and so two methods of calculation of 'original' nitrate concentrations used in earlier studies have been reviewed. Nitrite at intermediate depths was not restricted to the Persian Gulf water; concentrations were maximal much shallower than the depths of the Persian Gulf water. The nitrate-salinity relationship used to calculate 'original' nitrate concentrations in a recent study would lead to an underestimate of nitrate deficits because the approach requires denitrification to be restricted to Persian Gulf water. A method involving oxidative ratios has been modified and used to calculate nitrate deficits. The deficits so calculated lie between the values reported earlier. The degree of denitrification decreases steadily southward. The results indicate that denitrification extends up to 11 or 12°N latitude. Taking 30 years as the average residence time of water for the layer in which denitrification occurs, the denitrification rate in the Arabian Sea has been calculated as about 3.2 × 10 12 gy -1. This represents about 5% of the annual global denitrification.

  20. OCULUS Sea Track Fusion Service

    NASA Astrophysics Data System (ADS)

    Panagiotou, Stylianos C.; Rizogiannis, Constantinos; Katsoulis, Stavros; Lampropoulos, Vassilis; Kanellopoulos, Sotirios; Thomopoulos, Stelios C. A.

    2015-06-01

    Oculus Sea is a complete solution regarding maritime surveillance and communications at Local as well as Central Command and Control level. It includes a robust and independent track fusion service whose main functions include: 1) Interaction with the User to suggest the fusion of two or more tracks, confirm Track ID and Vessel Metadata creation for the fused track, and suggest de-association of two tracks 2) Fusion of same vessel tracks arriving simultaneously from multiple radar sensors featuring track Association, track Fusion of associated tracks to produce a more accurate track, and Multiple tracking filters and fusion algorithms 3) Unique Track ID Generator for each fused track 4) Track Dissemination Service. Oculus Sea Track Fusion Service adopts a system architecture where each sensor is associated with a Kalman estimator/tracker that obtains an estimate of the state vector and its respective error covariance matrix. Finally, at the fusion center, association and track state estimation fusion are carried out. The expected benefits of this system include multi-sensor information fusion, enhanced spatial resolution, and improved target detection.

  1. Studies on sea snake venom

    PubMed Central

    TAMIYA, Nobuo; YAGI, Tatsuhiko

    2011-01-01

    Erabutoxins a and b are neurotoxins isolated from venom of a sea snake Laticauda semifasciata (erabu-umihebi). Amino acid sequences of the toxins indicated that the toxins are members of a superfamily consisting of short and long neurotoxins and cytotoxins found in sea snakes and terrestrial snakes. The short neurotoxins to which erabutoxins belong act by blocking the nicotinic acetylcholine receptor on the post synaptic membrane in a manner similar to that of curare. X-ray crystallography and NMR analyses showed that the toxins have a three-finger structure, in which three fingers made of three loops emerging from a dense core make a gently concave surface of the protein. The sequence comparison and the location of essential residues on the protein suggested the mechanism of binding of the toxin to the acetylcholine receptor. Classification of snakes by means of sequence comparison and that based on different morphological features were inconsistent, which led the authors to propose a hypothesis “Evolution without divergence.” PMID:21422738

  2. A Climatological study of sea breezes in the Red Sea region of Saudi Arabia

    NASA Astrophysics Data System (ADS)

    Khan, Basit A.; Abualnaja, Yasser

    2015-04-01

    Long term near surface observations from 20 stations, buoys, high resolution model data from European Centre for Medium-Range Weather Forecasts (ECMWF) and Weather Research and Forecasting Modeling System (WRF(ARW)) are used to investigate the climatology of sea breezes over the Eastern side of the Red Sea region. Additionally, satellite data from second-generation Meteosat (MSG) and Radar soundings have also been analyzed to investigate major characteristics of sea breeze flow. Sea breezes blow under anticyclonic synoptic conditions, weak gradient winds, intense radiation, relatively cloud-free skies and strong near surface sea - land thermal gradient. In order to identify sea breeze signal a set of criteria based on synoptic condition, diurnal reversal of wind direction and thermal gradient has been devised. Results show that sea breezes in this region occur almost all year, but this meso-scale phenomenon is most frequent in summer months (May to August) when it occurs for almost half of the summer days. The onset of the sea breeze in this region is about 0800 LST (Local Standard Time). The sea breeze decays after 1700 LST, however, the timing of the onset and decay could be affected by season, sea-land thermal gradient, topography, sea-land orientation and the direction and strength of the prevailing wind. The depth of the predicted inflow layer reaches 1 kilometer while the height of sea breeze head may reach 3 kilometers. The rocky mountain range of Al-Sarawat, east of the Red Sea coast, restricts the inland propagation of sea breeze and significantly affects the structure of the flow. A detailed process analysis of the available data is being conducted to better understand the Sea Breeze and its effect on the local meteorology.

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

    USGS Publications Warehouse

    Barreira, S.; Compagnucci, R.

    2007-01-01

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

  4. Melting Ice, Rising Seas - Duration: 4 minutes, 32 seconds.

    NASA Video Gallery

    Sea level rise is an indicator that our planet is warming. Much of the world's population lives on or near the coast, and rising seas are something worth watching. Sea level can rise for two reason...

  5. Influence of the North Atlantic on climate change in the Barents Sea

    NASA Astrophysics Data System (ADS)

    Glok, Natalia; Alekseev, Genrikh; Smirnov, Aleksander; Vyasilova, Anastasia

    2015-04-01

    This study is based on the observations taken from the meteorological archives, satellite and historic visual observations of sea ice, global SST, data of water temperature in the upper layer on the section in the Barents Sea. For processing data was used factor analysis, calculation of correlation matrices with different delay between the Barents Sea and selected areas in North Atlantic. It is shown that the inflow of Atlantic water into the Barents Sea has a major influence on the climate of the region and its changes affect the variations of all climate characteristics. Decadal and interannual changes of air temperature in the Barents Sea are closely related (correlation over 0.8) with temperature of water, coming from the Norwegian Sea. The effect of these changes is seen in the air temperature in the Kara Sea. Atlantic water inflow especially impact on winter sea ice in the Barents Sea. The correlation between the average water temperature at section along the Kola meridian and sea ice extent in the Barents Sea in May reaches values of -0.86. To enhance the predictive capability established dependence, the study was extended to the area of the North Atlantic, where temperature anomalies are formed. In the North Atlantic from the equator to 80 ° N were identified 6 areas where the average annual SST anomalies are associated with SST anomalies and sea ice extent (SIE) in the Barents Sea. Detailed analysis with monthly SST from HadISST for 1951 - 2013 identified two areas with the greatest influence on the Barents Sea. One area is the northern region of the Gulf Stream and other is the equatorial region. The corresponding delays amounted to 26 months and 4-5 years. The relationship between changes AMO index, averaged over August-October, and SIE in the Barents Sea in January is evaluated. Correlation coefficient between them with 3 year delay is -0.54. Implemented study revealed the importance of teleconnection between SST anomalies in the North Atlantic and SST and SIE in the Barents Sea with a delay of several months to several years, which have prognostic significance. This research is supported by Ministry of Education and Science of the Russia (project RFMEFI61014X0006)

  6. Sea Stars Underwater Offshore Northern California

    Three sea stars on a rock, surrounded by a sandy seafloor littered with broken shells. Each sea star is approx. 10 - 15 cm (4-6 inches) across. Image acquired 4.5 km (3 miles) offshore Pigeon Point, southern San Mateo County, California at a depth of 52 meters....

  7. Color Difference in Bering Sea Phytoplankton Blooms

    NASA Technical Reports Server (NTRS)

    2002-01-01

    There is considerable color variation in the phytoplankton blooms in the Bering Sea -- from the aquamarine west of Nunivak Island to the almost reddish patch west of St. Matthew Island to the green eddy astride the International dateline at 60 North latitude and 178 East longitude. Credit: Provided by the SeaWiFS Project, NASA/Goddard Space Flight Center, and ORBIMAGE

  8. Teaching Wide Sargasso Sea in New Jersey

    ERIC Educational Resources Information Center

    Jolley, Susan Arpajian

    2005-01-01

    High school teacher Susan Arpajian Jolley emphasizes experience and understanding by using the related novels "Wide Sargasso Sea" and "Jane Eyre" to help her students travel into unfamiliar cultural territory. "Wide Sargasso Sea" relates to Caribbean history and culture, feminism, race relations, colonialism, and personal identity.

  9. The South Pole and the Ross Sea

    NASA Technical Reports Server (NTRS)

    2002-01-01

    This image shows a rare clear view of the South Pole (lower right) and the Ross Sea, Antarctica. The Sea-viewing Wide Field-of-view Sensor (SeaWiFS) acquired the scene on December 26, 2001. The geographic South Pole is located in the center of Antarctica, at an altitude of 2,900 meters (9,300 feet). It rests on a continent-wide ice sheet that is 2,870 m thick, with the underlying bedrock only 30 m (98 feet) above sea level. The ice underlying the South Pole is as much as 140,000 years old, and is currently accumulating at about 82 cm (32 inches) per year. Roughly 2,500 km (1,550 miles) away is the green water of the Ross Sea, which indicates the presence of large numbers of phytoplankton. This is a highly productive part of the world's oceans. Also note the ice gathered around McMurdo Sound, seen toward the lefthand shoreline of the Ross Sea, at the edge of the Ross Ice Shelf. According to National Science Foundation researchers, this ice is making it difficult for penguins to reach their food supply. Separating the continental Antarctic ice sheet from the Ross Sea are the Queen Maud Mountains and the Ross Ice Shelf. Image courtesy the SeaWiFS Project, NASA/Goddard Space Flight Center, and ORBIMAGE

  10. The strength anisotropia of sea ice

    SciTech Connect

    Evdokimov, G.N.; Rogachko, S.I.

    1994-12-31

    The hydraulic-engineering structure calculations of sea ice formation force require the sea ice strength data. The strength characteristics values and the types of sea ice formations in view of water depth define the type and the design of future structures in each particular region of supposed construction. The most objective information on the sea ice physical and technical properties can be obtained by field investigations ad the existing methods of their calculations refer to a great number of errors. The accumulated bank of data on studying the sea ice formation strength properties show one that ice as a natural material is of great crystalline structure variety. The level ice fields have a number of particularities. The crystal sizes increase in ice thickness. The crystals consist of fresh-water thin plates 0.5--0.6 mm in thickness oriented by pickle-water interlayers. Difference in thickness of the sea ice cover structure is one of the main causes of the changes strength characteristics layer. Besides that the sea ice strength depends upon the destroying force direction in reference to crystal orientation which characterizes the sea ice anisotropia as a material.

  11. The application of ERTS imagery to monitoring Arctic sea ice. [mapping ice in Bering Sea, Beaufort Sea, Canadian Archipelago, and Greenland Sea

    NASA Technical Reports Server (NTRS)

    Barnes, J. C. (Principal Investigator); Bowley, C. J.

    1974-01-01

    The author has identified the following significant results. Because of the effect of sea ice on the heat balance of the Arctic and because of the expanding economic interest in arctic oil and minerals, extensive monitoring and further study of sea ice is required. The application of ERTS data for mapping ice is evaluated for several arctic areas, including the Bering Sea, the eastern Beaufort Sea, parts of the Canadian Archipelago, and the Greenland Sea. Interpretive techniques are discussed, and the scales and types of ice features that can be detected are described. For the Bering Sea, a sample of ERTS-1 imagery is compared with visual ice reports and aerial photography from the NASA CV-990 aircraft. The results of the investigation demonstrate that ERTS-1 imagery has substantial practical application for monitoring arctic sea ice. Ice features as small as 80-100 m in width can be detected, and the combined use of the visible and near-IR imagery is a powerful tool for identifying ice types. Sequential ERTS-1 observations at high latitudes enable ice deformations and movements to be mapped. Ice conditions in the Bering Sea during early March depicted in ERTS-1 images are in close agreement with aerial ice observations and photographs.

  12. Sea surface temperature measurements with AIRS

    NASA Technical Reports Server (NTRS)

    Aumann, H.

    2003-01-01

    The comparison of global sea surface skin temperature derived from cloud-free AIRS super window channel at 2616 cm-1 (sst2616) with the Real-Time Global Sea Surface Temperature for September 2002 shows surprisingly small standard deviation of 0.44K.

  13. More on Sea Turtles and Seaweed

    ERIC Educational Resources Information Center

    Xin, Tian

    2005-01-01

    "Sea turtle" and "seaweed"--otherwise known as "returnee from abroad" and "unemployed from abroad," respectively-- are a pair of popular new terms that are innately connected. In this article, the author discusses the common plight faced by "sea turtles" and "seaweeds" who returned from abroad to work in China. The author describes the experiences

  14. More on Sea Turtles and Seaweed

    ERIC Educational Resources Information Center

    Xin, Tian

    2005-01-01

    "Sea turtle" and "seaweed"--otherwise known as "returnee from abroad" and "unemployed from abroad," respectively-- are a pair of popular new terms that are innately connected. In this article, the author discusses the common plight faced by "sea turtles" and "seaweeds" who returned from abroad to work in China. The author describes the experiences…

  15. Sea-Ice Roughness, Morphogenesis and Kinematics --- Approaches to Learn from the Complexity of Sea Ice

    NASA Astrophysics Data System (ADS)

    Herzfeld, U. C.; Williams, S.; Maslanik, J.

    2007-12-01

    Recent studies of the alarming retreat of the Arctic sea ice have been largely based on observations of sea-ice coverage. This is not sufficient to capture changes in the sea-ice's mass, hence there is an increasing interest in measuring the thickness of sea-ice. However, the complexity of sea ice renders the latter a difficult task: (1) at any time, the sea ice has a complex form and appearance in remote-sensing observations, (2) due to ridging and rubbling, the mass of sea ice is not directly related to its thickness, (3) sea ice forms in a series of morphogenetic processes, and (4) sea ice moves. Here we present mathematical approaches to analyze spatial roughness of the surface of sea ice and of its snow-layer thickness, morphogenetic processes and deformation characteristics as a means to quantify and characterize sea-ice properties, processes and provinces. Applications include analyses of passive microwave data, SAR data, laser and radar elevation data and multispectral image data, from satellite, unmanned aerial vehicle and aircraft platforms, and field data.

  16. Dynamic response of the Black Sea elevation to intraseasonal fluctuations of the Mediterranean sea level

    NASA Astrophysics Data System (ADS)

    Volkov, Denis L.; Johns, William E.; Belonenko, Tatyana V.

    2016-01-01

    Response of the Black Sea elevation to intraseasonal sea level changes in the Mediterranean is studied using satellite altimetry data and a linear analytical model. Satellite observations show that the nonseasonal sea level in the Black Sea (η1) is coherent with that in the Aegean and Marmara Seas (η0) but lags behind them by 10-40 days at subannual periods. The observed time lag is mainly due to friction that constrains the exchange through the Bosphorus Strait. Using realistic friction and characteristic η0 forcing in the model, we find that the amplitude of η1 reaches the amplitude of η0 at about 1 year period, and the time lag increases from 10 to 22 days at periods 50-250 days. Freshwater fluxes, atmospheric pressure, and to a smaller extent the along-strait wind also influence the Black Sea elevation, but sea level fluctuations in the Mediterranean appear to be the dominant forcing mechanism.

  17. Predictability of the Arctic sea ice edge

    NASA Astrophysics Data System (ADS)

    Goessling, H. F.; Tietsche, S.; Day, J. J.; Hawkins, E.; Jung, T.

    2016-02-01

    Skillful sea ice forecasts from days to years ahead are becoming increasingly important for the operation and planning of human activities in the Arctic. Here we analyze the potential predictability of the Arctic sea ice edge in six climate models. We introduce the integrated ice-edge error (IIEE), a user-relevant verification metric defined as the area where the forecast and the "truth" disagree on the ice concentration being above or below 15%. The IIEE lends itself to decomposition into an absolute extent error, corresponding to the common sea ice extent error, and a misplacement error. We find that the often-neglected misplacement error makes up more than half of the climatological IIEE. In idealized forecast ensembles initialized on 1 July, the IIEE grows faster than the absolute extent error. This means that the Arctic sea ice edge is less predictable than sea ice extent, particularly in September, with implications for the potential skill of end-user relevant forecasts.

  18. The South China Sea Deep: Introduction

    NASA Astrophysics Data System (ADS)

    Wang, Pinxian; Li, Qianyu; Dai, Minhan

    2015-12-01

    The South China Sea (SCS) has increasingly become a global focus in ocean research and hydrocarbon explorations. Over the last two decades, at least 17 international cruises including two ODP/IODP expeditions were conducted in the SCS, and more than 2000 exploratory wells were drilled (Wang et al., 2014a). While its sedimentary basins on the continental shelf and slope are explored for offshore resources, the deep basin below 3500 m in depth that overlies the basaltic oceanic crust preserves the key to understanding their formation and development. In order to better understand the life history and functional system of the marginal sea, a major research program "Deep Sea Processes and Evolution of the South China Sea", or "The South China Sea Deep" for short, was launched in January 2011 by the National Natural Science Foundation (NSFC) of China. This venture represents the first ever large-scale basic-research program in ocean science in the country (Wang, 2012).

  19. Brine-ecosystem interactions in sea ice

    NASA Astrophysics Data System (ADS)

    Vancoppenolle, M.; Bitz, C. M.; Fichefet, T.; Goosse, H.; Lancelot, C.; Tison, J.

    2010-12-01

    Microalgae grow in brine inclusions in sea ice. Previous sea ice-ecosystem models neglect brine-microalgae interactions, prescribing the location of the microbial communities. In this study, a sea ice model with explicit brine dynamics coupled to a simple nutrient-phytoplankton (N-P) module (diatoms and dissolved silicates) is introduced. The model predicts bottom and surface microalgal populations. In fall, brine convection in cooling ice supplies nutrients, which favors microalgal growth. In early summer, the vertical brine density profile in warmer ice stabilizes, nutrient supply shuts off, which prevents further biomass building. Sensitivity tests in an idealized Antarctic pack ice configuration suggest that mode of microalgal transport within brine (passive or active) induces important population differences. This study is a step toward a more realistic sea ice-ecosystem model, which is required to understand the role of sea ice and associated ecosystems in global biogeochemical cycles.

  20. Sea Level Rise in Tampa Bay

    NASA Astrophysics Data System (ADS)

    Cronin, Thomas; Edgar, N. Terence; Brooks, Gregg; Hastings, David; Larson, Rebekka; Hine, Albert; Locker, Stanley; Suthard, Beau; Flower, Benjamin; Hollander, David; Wehmiller, John; Willard, Debra; Smith, Shannon

    2007-03-01

    Understanding relative sea level (RSL) rise during periods of rapid climatic change is critical for evaluating modern sea level rise given the vulnerability of Antarctic ice shelves to collapse, the retreat of the world's glaciers, and mass balance trends of the Greenland ice sheet. The first-order pattern of global sea level rise following the Last Glacial Maximum (LGM, ~21,000 years ago) is well established from coral, continental shelf, and other records and has been integrated into a global ICE-5G model of glacio-isostatic adjustment (GIA). However, uncertainty introduced by paleo water depth of sea level indicators, radiocarbon chronology (i.e., reservoir corrections for marine shell dates), postglacial isostatic adjustment, and other processes affecting vertical position of former shorelines produces scatter in RSL curves, limiting our knowledge of sea level rise during periods of rapid glacial decay.

  1. Volga River Delta and Caspian Sea

    NASA Technical Reports Server (NTRS)

    2002-01-01

    This true-color MODIS image from May 10, 2002, captures Russia's Volga River (running south through the center) emptying into the northern portion of the Caspian Sea. The waters of the Caspian Sea are quite murky in this image, highlighting the water quality problems plaguing the sea. The sea is inundated with sewage and industrial and agricultural waste, which is having measurable impact on human health and wildlife. According reports from the Department of Energy, in less than a decade the sturgeon catch dropped from 30,000 tons to just over 2,000 tons. National and international groups are currently joining together to find strategies of dealing with the environmental problems of the Caspian Sea. Credit: Jacques Descloitres, MODIS Land Rapid Response Team, NASA/GSFC

  2. Loss of sea ice in the Arctic.

    PubMed

    Perovich, Donald K; Richter-Menge, Jacqueline A

    2009-01-01

    The Arctic sea ice cover is in decline. The areal extent of the ice cover has been decreasing for the past few decades at an accelerating rate. Evidence also points to a decrease in sea ice thickness and a reduction in the amount of thicker perennial sea ice. A general global warming trend has made the ice cover more vulnerable to natural fluctuations in atmospheric and oceanic forcing. The observed reduction in Arctic sea ice is a consequence of both thermodynamic and dynamic processes, including such factors as preconditioning of the ice cover, overall warming trends, changes in cloud coverage, shifts in atmospheric circulation patterns, increased export of older ice out of the Arctic, advection of ocean heat from the Pacific and North Atlantic, enhanced solar heating of the ocean, and the ice-albedo feedback. The diminishing Arctic sea ice is creating social, political, economic, and ecological challenges. PMID:21141043

  3. Geomagnetic Navigation in Sea Turtles

    NASA Astrophysics Data System (ADS)

    Lohmann, K.; Putman, N.; Lohmann, C.

    2011-12-01

    Young loggerhead sea turtles (Caretta caretta) from eastern Florida undertake a transoceanic migration in which they gradually circle the north Atlantic Ocean before returning to the North American coast. Newly hatched turtles (hatchlings) begin the migration with a 'magnetic map' in which regional magnetic fields function as navigational markers and elicit changes in swimming direction at crucial geographic boundaries. In laboratory experiments, young turtles that had never before been in the ocean were exposed to fields like those that exist at various, widely separated locations along their transoceanic migratory route. Turtles responded by swimming in directions that would, in each case, help them remain within the North Atlantic gyre currents and advance along the migratory pathway. The results demonstrate that turtles can derive both longitudinal and latitudinal information from the Earth's field, and provide strong evidence that hatchling loggerheads inherit a remarkably elaborate set of responses that function in guiding them along their open-sea migratory route. For young sea turtles, couplings of oriented swimming to regional magnetic fields appear to provide the fundamental building blocks from which natural selection can sculpt a sequence of responses capable of guiding first-time ocean migrants along complex migratory routes. The results imply that hatchlings from different populations in different parts of the world are likely to have magnetic navigational responses uniquely suited for the migratory routes that each group follows. Thus, from a conservation perspective, turtles from different populations are not interchangeable. From an evolutionary perspective, the responses are not incompatible with either secular variation or magnetic polarity reversals. As Earth's field gradually changes, strong selective pressure presumably acts to maintain an approximate match between the responses of hatchlings and the fields that exist at critical points along the migratory pathway at any point in time. Although responses to regional fields might be rendered useless during occasional periods of rapid field change associated with magnetic polarity reversals or excursions, these sporadic events do not preclude the evolution of magnetic responses during the intervening and usually much longer intervals when Earth's field changes more slowly and is relatively stable.

  4. Coherent sea level variation in and around the Sea of Okhotsk

    NASA Astrophysics Data System (ADS)

    Nakanowatari, Takuya; Ohshima, Kay I.

    2014-08-01

    We investigated the seasonal and interannual variations of the sea level in and around the Sea of Okhotsk and their causes, based on tide gauge and satellite altimeter data. The sea level all along the coastal region of the Sea of Okhotsk is found to be dominated by the seasonal variation with a maximum in winter and a minimum in summer, which cannot be explained by the annual cycle of atmospheric heat flux and pressure. This sea level variation appears to reflect ocean current variations. Both the Arrested Topographic Waves (ATWs) caused by alongshore wind stress and the Sverdrup transport by wind stress curl show corresponding seasonal variations. Seasonal amplitude of the sea level is relatively large along Sakhalin Island with a tendency of a larger amplitude toward the south. This meridional dependence is consistent with the ATWs, but not with the Sverdrup transport in the Sea of Okhotsk. Seasonal variation of the geostrophic current velocity expected from the sea level variation is comparable to that of the observed nearshore current and is consistent with the theoretical ATW transport. It is also revealed that, on an interannual timescale, the wintertime sea level fluctuates quite coherently all around the Sea of Okhotsk and further along the East Kamchatka and Oyashio coasts in the North Pacific. The altimeter data clearly show that this coherent sea level variation is trapped over the coastal and continental shelf regions with depths shallower than 1000 m. The wintertime sea levels have a higher correlation with the ATW transport than with the Sverdrup transport in the Sea of Okhotsk and the upstream East Kamchatka coast. All these suggest that the interannual sea level variation along the coastal and shelf regions in winter, as well as the seasonal variation, is mainly caused by the ATWs (coastal trapped current forced by the alongshore wind stress). The wintertime Sverdrup transport, raised by the previous studies, is the secondary contributor to these variations.

  5. Sea Ice Biogeochemistry: A Guide for Modellers

    PubMed Central

    Tedesco, Letizia; Vichi, Marcello

    2014-01-01

    Sea ice is a fundamental component of the climate system and plays a key role in polar trophic food webs. Nonetheless sea ice biogeochemical dynamics at large temporal and spatial scales are still rarely described. Numerical models may potentially contribute integrating among sparse observations, but available models of sea ice biogeochemistry are still scarce, whether their relevance for properly describing the current and future state of the polar oceans has been recently addressed. A general methodology to develop a sea ice biogeochemical model is presented, deriving it from an existing validated model application by extension of generic pelagic biogeochemistry model parameterizations. The described methodology is flexible and considers different levels of ecosystem complexity and vertical representation, while adopting a strategy of coupling that ensures mass conservation. We show how to apply this methodology step by step by building an intermediate complexity model from a published realistic application and applying it to analyze theoretically a typical season of first-year sea ice in the Arctic, the one currently needing the most urgent understanding. The aim is to (1) introduce sea ice biogeochemistry and address its relevance to ocean modelers of polar regions, supporting them in adding a new sea ice component to their modelling framework for a more adequate representation of the sea ice-covered ocean ecosystem as a whole, and (2) extend our knowledge on the relevant controlling factors of sea ice algal production, showing that beyond the light and nutrient availability, the duration of the sea ice season may play a key-role shaping the algal production during the on going and upcoming projected changes. PMID:24586604

  6. Sea ice-albedo climate feedback mechanism

    SciTech Connect

    Schramm, J.L.; Curry, J.A.; Ebert, E.E.

    1995-02-01

    The sea ice-albedo feedback mechanism over the Arctic Ocean multiyear sea ice is investigated by conducting a series of experiments using several one-dimensional models of the coupled sea ice-atmosphere system. In its simplest form, ice-albedo feedback is thought to be associated with a decrease in the areal cover of snow and ice and a corresponding increase in the surface temperature, further decreasing the area cover of snow and ice. It is shown that the sea ice-albedo feedback can operate even in multiyear pack ice, without the disappearance of this ice, associated with internal processes occurring within the multiyear ice pack (e.g., duration of the snow cover, ice thickness, ice distribution, lead fraction, and melt pond characteristics). The strength of the ice-albedo feedback mechanism is compared for several different thermodynamic sea ice models: a new model that includes ice thickness distribution., the Ebert and Curry model, the Mayjut and Untersteiner model, and the Semtner level-3 and level-0 models. The climate forcing is chosen to be a perturbation of the surface heat flux, and cloud and water vapor feedbacks are inoperative so that the effects of the sea ice-albedo feedback mechanism can be isolated. The inclusion of melt ponds significantly strengthens the ice-albedo feedback, while the ice thickness distribution decreases the strength of the modeled sea ice-albedo feedback. It is emphasized that accurately modeling present-day sea ice thickness is not adequate for a sea ice parameterization; the correct physical processes must be included so that the sea ice parameterization yields correct sensitivities to external forcing. 22 refs., 6 figs., 1 tab.

  7. Complex Stratigraphic Evolution of the Red Sea

    NASA Astrophysics Data System (ADS)

    Almalki, Khalid A.; Mahmud, Syed A.

    2015-04-01

    The Red Sea rift, separates the African and the Arabian continents, and is considered a type location of a juvenile rift-related small ocean. Geological studies and drilling programs date back to more than half a century yet very little is known about the stratigraphic evolution to the wider geological community. Following the arrival of the Afar plume at the late Oligocene (ca 30 Ma) the southern Red Sea underwent rapid extension culminating in extended continental crust or seafloor spreading, which stalled during the early Miocene at the central Red Sea due to either slowing of the convergence between Arabia and Eurasia or the onset of the Arabian plate passive margin collision with Eurasia. The mainland pan of the region was uplifted, resulting in the development of the Red Sea erosional escarpment. Shelf sedimentation (Middle-late Miocene to Pleistocene successions) then ensued and covered oceanic and continental crust. The present day spreading centre resumed in the southern Red Sea at 5 Ma and has been propagating northward until the present-day. However, detailed analysis of the basin shows a more complex pattern of basin development with late Oligocene succession restricted to the western Red Sea coast and the southern sectors. Well data suggest that up to 4 km of sediments exist in the southern Red Sea shallowing upward to the northern sector; 3 km or more of this section consists of Miocene evaporates, which contains intercalated anhydrite and shale horizons. These Miocene evaporates are overlain by Quaternary reefal limestone, and recent volcanic rocks restricted to the central axial trough zone of the Red Sea. In this study extensive well data that is well spread in the area was used to evaluate the stratigraphic architecture, build-ups, and local controls on deposition. Potential stratigraphic models have been developed. The distribution of stratigraphy in the Red Sea area yields complex correlation, with unique depositional characteristics in discrete zones within the Red Sea basin.

  8. Is sea salt in ice cores a proxy of past sea ice extent?

    NASA Astrophysics Data System (ADS)

    Levine, James; Wolff, Eric; Frey, Markus; Jenkins, Hazel; Jones, Anna; Yang, Xin

    2014-05-01

    A number of marine, coastal and ice core proxies have been used to try to assess the past extent of sea ice. Sea salt has been proposed as a proxy for past ice extent, at least in the Southern Ocean. The idea is that the sea ice surface itself holds a source of sea salt, that is stronger than the source from the open ocean it replaces. That a sea ice source exists is apparent from observations of the ratio of sulphate to sodium in coastal aerosol and snow samples. While the idea behind using sea salt as a proxy is attractive, and leads to sensible inferences, many doubts remain. Firstly the exact nature of the source remains uncertain, and secondly it is not clear if ice extent, as opposed to changes in atmospheric transport and lifetime, would dominate variability in the ice core record of sea salt. Here we use a model of atmospheric transport and chemistry (p-TOMCAT) to assess the consequences of a sea ice source, focussing particularly on a source that has been proposed to arise from the sublimation of salty blowing snow. We will briefly report some new observations from a winter cruise, that will allow us to comment on the likelihood that blowing snow does pose a significant source. We will then present results from the model (implemented using existing parameters). The model has been run with seasonally and interannually varying sea ice extent and meteorology for the Antarctic, tracking, at different ice core sites, the concentration that arises from the open ocean and sea ice sources. We have already shown that the model, after tuning, is able to reproduce the magnitude and seasonal cycle of sea salt at a range of sites globally. By varying each component separately we explore which factors (sea ice presence, wind speed at source, transporting winds) and which source regions control the delivery of sea salt to sites in Antarctica. Such work suggests that sea salt cannot be used as a sea ice proxy on interannual timescales, but may be suitable on longer timescales. By employing much larger sea ice extents, such as at the last glacial maximum (LGM), we find a strong increase in concentration at ice core sites when ice extent increases. The increase in modelled sea salt concentration tails off sharply as ice approaches the LGM extent, so that the sensitivity of the proxy is greater at lower ice extents, for example in interglacials. We will discuss the implications of this work for the proposed use of sea salt as a sea ice proxy.

  9. SEAS: Student Experiments At Sea - An Education Outreach Pilot Program Sponsored by the Ridge2000 Program

    NASA Astrophysics Data System (ADS)

    Goehring, L.

    2004-12-01

    SEAS is a pilot program for middle and high school students who want to learn science by doing science. SEAS students study the deep sea hydrothermal vent environment and learn to ask questions about this exciting, relatively unexplored world, just as researchers do. SEAS students also learn how to answer their own questions through the process of scientific investigation. With the SEAS program, students have the opportunity to participate in the actual discovery process, along side deep-sea researchers. SEAS builds upon the successes of programs like Dive&Discover and Extreme2000, which demonstrated the capability deep-sea scientists have in engaging students with live research. SEAS extends this concept by inviting students to participate in deep-sea research through formal proposal and report competitions. SEAS challenges students to higher levels of achievement. A curriculum, developed by teachers expert in the translation of scientific inquiry in the classroom, prepares students to participate. SEAS was concept-tested during the 2003-2004 school year, with 14 pilot teachers and approximately 800 students. Twenty Ridge2000 scientists contributed their time and expertise to the SEAS program in its first year. Five student proposals were selected and conducted at sea in April during a Ridge2000 research cruise to the East Pacific Rise. All results were posted to the SEAS website (http://www.ridge2000.org/SEAS/) during the cruise, and students were invited to analyze data for their final reports. Final student reports, along with scientists comments were also posted. During the 2004-2005 school year, SEAS will be evaluated for its impact on student learning and attitudes toward science. The benefits of SEAS to the Ridge2000 scientific community are many. Scientists are invited to contribute in a variety of ways, all of which help satisfy the requirement of NSFs Broader Impacts Criterion. They may contribute time and expertise by answering student questions and reviewing student proposals and reports. They may choose to host the student research on their cruise. By sharing the load, no one scientist is burdened, nor expected to contribute additional funding. The Ridge2000 Program oversees the development, execution and dissemination of SEAS, helping make outreach efficient and easy for scientists.

  10. SEAS Classroom to Sea Labs: New Directions for Ridge 2000 Communitywide Education Outreach

    NASA Astrophysics Data System (ADS)

    Goehring, L.

    2005-12-01

    Lessons learned from the two year SEAS pilot program emphasize that student participation in deep-sea research is an important motivator in student learning. Further, SEAS students experience a paradigm shift in understanding evidence-based reasoning and the process of scientific discovery. At the same time, we have learned that fostering authentic student investigations within the confines of the academic year is challenging and only fits classrooms with some academic flexibility. As a result, this year, SEAS will focus on the new Classroom to Sea Lab as a means to help foster student inquiry in the secondary school science classroom. The Classroom to Sea Lab invites student participation in deep-sea research but does so without requiring students to identify and propose suitable sea-going experiments. Classroom to Sea labs are designed to feature current deep-sea research, and emphasize critical skills in laboratory techniques, data collection and analysis, and scientific reporting. Labs are conducted in the classroom (by students) and at sea (by scientists for the students), resulting in parallel datasets for comparison. Labs also feature the work of practicing scientists. An annual Classroom to Sea Report Fair invites students to summarize their findings and submit written analyses for scientist feedback and prizes, emphasizing the importance of communications skills in science. This year, the SEAS program will feature the Shallow-water vs. Deep-sea Vent Mussel Classroom to Sea lab. In this lab, students explore differences in mussel anatomy and feeding strategies, and understand how chemosynthetic symbionts function in this animal. The lab instructs students to dissect shallow-water mussels and measure the proportion of gill tissue to total body tissue. Students are also instructed to download a dataset of vent mussel measurements and compare average proportions. Finally, students are invited to submit their analyses of the lab to the on-line Report Fair sponsored by the Ridge 2000 research community. A primary goal of SEAS is to excite and engage student learners by involving them in actual research in the extreme environments of the deep-sea. The program depends on the contributions of multiple scientists within the Ridge 2000 community. Scientists field student questions during the Ask-a-Scientist email forum, serve as Report Reviewers, are featured in ``Scientist Spotlights,'' host educators during cruises to conduct at-sea portions of a lab, and help develop new labs. It is community involvement that makes the SEAS program possible and so exciting and motivating for students.

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

    NASA Astrophysics Data System (ADS)

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

    2012-03-01

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

  12. Measuring the sea quark polarization

    SciTech Connect

    Makdisi, Y.; RHIC Spin Collaboration

    1993-06-01

    Spin is a fundamental degree of freedom and measuring the spin structure functions of the nucleon should be a basic endeavor for hadron physics. Polarization experiments have been the domain of fixed target experiments. Over the years large transverse asymmetries have been observed where the prevailing QCD theories predicted little or no asymmetries, and conversely the latest deep inelastic scattering experiments of polarized leptons from polarized targets point to the possibility that little of the nucleon spin is carried by the valence quarks. The possibility of colliding high luminosity polarized proton beams in the Brookhaven Relativistic Heavy Ion Collider (RHIC) provides a great opportunity to extend these studies and systematically probe the spin dependent parton distributions specially to those reactions that are inaccessible to current experiments. This presentation focuses on the measurement of sea quark and possibly the strange quark polarization utilizing the approved RHIC detectors.

  13. Measuring the sea quark polarization

    SciTech Connect

    Makdisi, Y.

    1993-01-01

    Spin is a fundamental degree of freedom and measuring the spin structure functions of the nucleon should be a basic endeavor for hadron physics. Polarization experiments have been the domain of fixed target experiments. Over the years large transverse asymmetries have been observed where the prevailing QCD theories predicted little or no asymmetries, and conversely the latest deep inelastic scattering experiments of polarized leptons from polarized targets point to the possibility that little of the nucleon spin is carried by the valence quarks. The possibility of colliding high luminosity polarized proton beams in the Brookhaven Relativistic Heavy Ion Collider (RHIC) provides a great opportunity to extend these studies and systematically probe the spin dependent parton distributions specially to those reactions that are inaccessible to current experiments. This presentation focuses on the measurement of sea quark and possibly the strange quark polarization utilizing the approved RHIC detectors.

  14. Tides of the Caribbean Sea

    SciTech Connect

    Kjerfve, B.

    1981-05-20

    Analysis of tidal characteristics from 45 gauge locations indicates that the Caribbean Sea has a microtidal range, for the most part between 10 and 20 cm. The tide is primarily either mixed semidiurnal or mixed diurnal but a substantial section from Puerto Rico to Venezuela experiences diurnal tides. Empirical charts of six component tides (M/sub 2/, S/sub 2/, N/sub 2/, K/sub 1/, O/sub 1/, and P/sub 1/) show local detail of phase and amplitude. Each of the semidiurnal component tides is characterized by anticlockwise rotating amphidromes centered in the eastern Caribbean. There is evidence of strong radiational forcing of the S/sub 2/ tide in the south-western Caribbean. The diurnal component tides are largely uniform in both phase and amplitude for most of the western and central Caribbean. However, the diurnal phases increase rapidly towards the northwest and the Yucatan Channel.

  15. Family conflicts in the sea.

    PubMed

    Kamel, Stephanie Jill; Grosberg, Richard K; Marshall, Dustin J

    2010-08-01

    In sexually reproducing organisms, conflicts of interest among family members are inevitable. The intensity of these conflicts depends upon the opportunities for parents and offspring to interact and the level of promiscuity. Despite the acknowledged role of family conflict in the evolutionary ecology of terrestrial organisms, its influence in the marine realm has largely been ignored. Nevertheless, marine organisms exhibit a wide range of reproductive and developmental modes through which sexual, sibling, and parent-offspring conflicts can manifest. Moreover, the existence of multiple mating in these species increases the likelihood, as well as the degree, of these conflicts. Consequently, many puzzling aspects of evolution in the sea, from life-history variation to diversification, could be clarified through the lens of conflict theory. PMID:20557975

  16. Sea level change: a philosophical approach

    NASA Astrophysics Data System (ADS)

    Leinfelder, R.; Seyfried, H.

    1993-07-01

    The present Cenozoic era is an ‘icehouse’ episode characterized by a low sea level. Since the beginning of the industrial revolution, the human race has been emitting greenhouse gases, increasing the global atmospheric temperature, and causing a rise in sea level. If emissions continue to increase at the present rate, average global temperatures may rise by 1.5°C by the year 2050, accompanied by a rise of about 30 cm in sea level. However, the prediction of future climatic conditions and sea level is hampered by the difficulty in modelling the interactions between the lithosphere, kryosphere, biosphere and atmosphere; in addition, the buffering capacity of our planet is still poorly understood. As scientists cannot offer unambiguous answers to simple questions, sorcerer's apprentices fill in the gaps, presenting plans to save planet without inconveniencing us. The geological record can help us to learn about the regulation mechanisms of our planet, many of which are connected with or expressed as sea level changes. Global changes in sea level are either tectono-eustatic or glacioeustatic. Plate tectonic processes strongly control sea levels and climate in the long term. There is a strong feed-back mechanism between sea level and climate; both can influence and determine each other. Although high sea levels are a powerful climatic buffer, falling sea levels accelerate climatic accentuation, the growth of the polar ice caps and will hence amplify the drop in sea level. Important sources of fossil greenhouse gases are botanic CO2 production, CO2 released by volcanic activity, and water vapour. The latter is particularly important when the surface area of the sea increases during a rise in sea level (‘maritime greenhouse effect’). A ‘volcanogenic greenhouse effect’ (release of volcanogenic CO2) is possibly not equally important, as intense volcanic activity may take place both during icehouse episodes as well as during greenhouse episodes. The hydrosphere, land vegetation and carbonate platforms are major CO2 buffers which may both take up and release CO2. CO2 can be released from the ocean due to changes in the pCO2 caused by growth of coral reefs and by uptake of CO2-rich freshwater from karst provinces. Efficient sinks of CO2 are the weathering products of silicate rocks; long-term sinks are organic deposits caused by regional anoxic events which preferrably develop during sea level rises and highstands; and coal-bearing strata. Deposition of limestone also removes CO2 from the atmospheric-hydrospheric cycle at a long term. Biotic crises are often related to either sea-level lows or sea-level highs. Long-term sea-level lows, characteristic of glacial periods, indicate cooling as major cause of extinction. During verly long-lasting greenhouse episodes the sea level is very high, climate and circulation systems are stable and biotic crises often develop as a consequence of oxygen depletion. On land, niche-splitting, complex food web structures and general overspecialization of biota will occur. Whether the crisis is caused by a single anoxic event (e.g. in the Late Devonian) or a disturbance by an asteroid impact (e.g. the Cretaceous/Tertiary boundary), it will only trigger total collapse of an ecosystem if a large part of it was already in decline. The regulatory mechanisms and buffers are thermodynamically extremely efficient if they are given sufficient time in which to deploy their power. However, after major catastrophes the re-establishment of successful ecosystems will take millions of years. The present rate of sea level and associated temperature rise is much too fast to be compensated and buffered by the network of natural controls. It is likely that the transitional time towards a new steady state will be an extremely variable and chaotic episode of unpredictable duration.

  17. Review of critical factors for SEA implementation

    SciTech Connect

    Zhang Jie Christensen, Per; Kornov, Lone

    2013-01-15

    The implementation process involved in translating Strategic Environmental Assessment (SEA) intention into action is vital to an effective SEA. Many factors influence implementation and thus the effectiveness of an SEA. Empirical studies have identified and documented some factors influencing the implementation of an SEA. This research is fragmented, however, and it is still not clear what are the most critical factors of effective SEA performance, and how these relate to different stages of the implementation process or other contextual circumstances. The paper takes its point of departure in implementation theory. Firstly, we introduce implementation theory, and then use it in practice to establish a more comprehensive model related to the stages in the implementation process. Secondly, we identify the critical factors in order to see how they are related to the different stages of SEA or are more general in character. Finally we map the different critical factors and how they influence the overall results of an SEA. Based on a literature review, we present a comprehensive picture of the critical factors and where they are found in the process. We conclude that most of the critical factors identified are of a more general character influencing the SEA process as such, while only one out of four of these factors relates to the specific stages of the SEA. Based on this mapping we can sketch a picture of the totality of critical factors. In this study 266 notions of critical factors were identified. Seen at the level of notions of critical factors, only 24% of these relate to specific stages while for 76% the critical factors are of a more general nature. These critical factors interact in complex ways and appear in different combinations in different stages of the implementation process so tracing the cause and effect is difficult. The pervasiveness of contextual and general factors also clearly suggests that there is no single way to put SEA into practice. The paper identifies some of the critical factors for effective SEA implementation, but further research is still needed to conclude which factors are more critical than others, just as the contingencies on which they depend are not easy to unravel. - Highlights: Black-Right-Pointing-Pointer The research on critical factors influencing SEA implementation is fragmented. Black-Right-Pointing-Pointer The critical factors are used to discuss 'hot-spots' in the implementation process. Black-Right-Pointing-Pointer Critical factors are just as broad as the concept of effectiveness. Black-Right-Pointing-Pointer Both stage and general factors are relevant in explaining the effectiveness of SEA.

  18. Crustal architecture and basin evolution in the Barents Sea

    NASA Astrophysics Data System (ADS)

    Faleide, J.; Team, P.

    2008-12-01

    The Barents Sea comprises a wide range of crustal and basin architectures that formed in response to different geological processes. In particular there are major differences between the western and eastern Barents Sea. The eastern Barents Sea is underlain by a wide (300-400 km) and deep (15-20 km) sedimentary basin that extends for more than 1000 km in a north-south direction. The basin formed by rapid subsidence in Late Permian-Early Triassic times. There are few signs of faulting associated with basin formation and it does not look like typical rift basins. There is a clear spatial correlation between the deep East Barents Sea Basin and the thickness of a high-velocity body in the upper mantle, and there is a temporal link between the main phase of basin formation and Siberian Traps magmatism. However, the links between the shallow and deep structure and any regional effects of the igneous activity are not well understood. The deep East Barents Sea Basin was filled by thick Triassic sediments prograding westwards from uplifted source area in the SE (Urals). Subsidence analysis assuming crustal stretching/thinning as the main driving force for sedimentary basin formation implies large Beta-values and a relatively hot basin scenario. However, taking into account the dimensions of the broad sag basin and the general lack of faulting it is not obvious whether this is a valid assumption. Alternatively, we are studying the role of phase transitions in the crust and upper mantle and how they could have contributed to subsidence in a colder basin scenario. In the western Barents Sea we find more typical rift basins formed in response to at least three major post-Caledonian rift phases: Carboniferous, Late Jurassic-Early Cretaceous, and Late Cretaceous-early Paleogene. The rifting activity migrated westwards through successive tectonic phases. Carboniferous rifting affected the entire western Barents Sea and gave rise to NE-SW to N-S trending horst and graben structures following a Caledonian basement grain. Late Jurassic-Early Cretaceous oblique extension in the deep SW Barents Sea basins was linked to the North Atlantic-Arctic plate tectonic evolution. A Late Cretaceous-Early Paleogene mega-shear system along the western Barents Sea-Svalbard margin (De Geer Zone) linked rifting, breakup and initial opening of the Norwegian-Greenland Sea and the Arctic Eurasia Basin. Most Barents Sea basins have also been affected by regional magmatism, compressional deformation and inversion and/or late uplift and erosion. These overprinting processes may have had important implications for the basin evolution and the petroleum systems. The different basin architectures and development are compared and discussed in relation to timing, deep crustal and upper mantle structures, and histories of vertical motion, basin filling and temperature.

  19. Crustal architecture and basin evolution in the Barents Sea

    NASA Astrophysics Data System (ADS)

    Faleide, J. I.; Petrobar Team

    2009-04-01

    The Barents Sea comprises a wide range of crustal and sedimentary basin architectures that formed in response to different geological processes. In particular there are major differences between the western and eastern Barents Sea. The eastern Barents Sea is underlain by a wide (300-400 km) and deep (15-20 km) sedimentary basin that extends for more than 1000 km in a north-south direction. The basin formed by rapid subsidence in Late Permian-Early Triassic times. There are few signs of faulting associated with basin formation and it does not look like typical rift basins. There is a clear spatial correlation between the deep East Barents Sea Basin and the thickness of a high-velocity body in the upper mantle, and there is a temporal link between the main phase of basin formation and Siberian Traps magmatism. However, the links between the shallow and deep structure and any regional effects of the igneous activity are not well understood. The deep East Barents Sea Basin was filled by thick Triassic sediments prograding westwards from uplifted source area in the SE (Urals). Subsidence analysis assuming crustal stretching/thinning as the main driving force for sedimentary basin formation implies large Beta-values and a relatively hot basin scenario. However, taking into account the dimensions of the broad sag basin and the general lack of faulting it is not obvious whether this is a valid assumption. Alternatively, we are studying the role of phase transitions in the crust and upper mantle and how they could have contributed to subsidence in a colder basin scenario. In the western Barents Sea we find more typical rift basins formed in response to at least three major post-Caledonian rift phases: Carboniferous, Late Jurassic-Early Cretaceous, and Late Cretaceous-early Paleogene. The rifting activity migrated westwards through successive tectonic phases. Carboniferous rifting affected the entire western Barents Sea and gave rise to NE-SW to N-S trending horst and graben structures following a Caledonian basement grain. Late Jurassic-Early Cretaceous oblique extension in the deep SW Barents Sea basins was linked to the North Atlantic-Arctic plate tectonic evolution. A Late Cretaceous-Early Paleogene mega-shear system along the western Barents Sea-Svalbard margin (De Geer Zone) linked rifting, breakup and initial opening of the Norwegian-Greenland Sea and the Arctic Eurasia Basin. Most Barents Sea basins have also been affected by regional magmatism, compressional deformation and inversion and/or late uplift and erosion. These overprinting processes may have had important implications for the basin evolution and the petroleum systems. The different basin architectures and development are compared and discussed in relation to timing, deep crustal and upper mantle structures, and histories of vertical motion, basin filling and temperature.

  20. Investigation of sea level trends and the effect of the north atlantic oscillation (NAO) on the black sea and the eastern mediterranean sea

    NASA Astrophysics Data System (ADS)

    Ozgenc Aksoy, Aysegul

    2016-03-01

    The North Atlantic Oscillation (NAO) has significant effects on sea levels, weather, and climate. In this study, the sea level trends and the effects of the North Atlantic Oscillation Indices (NAOI) on annual mean sea level data were assessed for the Black Sea and the Eastern Mediterranean Sea. The trends of sea level and NAOI were determined using Mann-Kendall dimensionless z statistics. Generally, upward sea level trends were detected for the Black Sea and the Eastern Mediterranean Sea. In the Black Sea, significant and continuous upward trends were detected after the year 1950. Weaker trends were detected for the Eastern part of the Mediterranean Sea. Sea level trends were correlated with trends in NAO indices; negative correlations were detected for the Black Sea, whereas positive correlations were found for the Eastern Mediterranean Sea. Paired t tests were performed to determine the turning points for all sea level data sets. The value of t was positive for all data sets, which means that the mean value of the data set before the turning point was smaller than the mean value of the data set after the turning point.

  1. Polar Seas Oceanography: An Integrated Case Study of the Kara Sea

    NASA Astrophysics Data System (ADS)

    Harms, Ingo

    2004-02-01

    What strikes first when browsing through this book is that the main title is misleading. Polar Seas Oceanography is, first of all, a book on ``an integrated case study of the Kara Sea,'' as the subtitle says. For readers who are interested more generally in polar oceanography, the book is probably the wrong choice. The Kara Sea is a rather shallow shelf sea within the Arctic Ocean, located between the Barents Sea to the west and the Laptev Sea to the east. The importance of the Kara Sea is manifold: climate change issues like ice formation and freshwater runoff, environmental problems from dumping of radioactive waste or oil exploitation, and finally, the Northern Sea route, which crosses large parts of the Kara Sea, underline the economical and ecological relevance of that region. In spite of severe climate conditions, the Kara Sea is relatively well investigated. This was achieved through intense oceanographic expeditions, aircraft surveys, and polar drift stations. Russian scientists from the Arctic and Antarctic Research Institute (AARI) carried out a major part of this outstanding work during the second half of the last century.

  2. Contribution of sea surface carbon pool to organic matter enrichment in sea spray aerosol

    NASA Astrophysics Data System (ADS)

    Quinn, Patricia K.; Bates, Timothy S.; Schulz, Kristen S.; Coffman, D. J.; Frossard, A. A.; Russell, L. M.; Keene, W. C.; Kieber, D. J.

    2014-03-01

    Breaking waves on the ocean surface generate air bubbles that scavenge organic matter from the surrounding sea water. When injected into the atmosphere, these bubbles burst, yielding sea spray aerosols enriched in organic matter, relative to the sea water. Downwind of plankton blooms, the organic carbon content of sea spray aerosol is weakly correlated with satellite-derived measurements of chlorophyll a levels, a measure of phytoplankton biomass. This correlation has been used in large-scale models to calculate the organic enrichment in sea spray aerosol. Here, we assess the relationship between the organic carbon content of sea water and freshly emitted sea spray aerosol in the presence and absence of plankton blooms in the North Atlantic Ocean and the coastal waters of California. The organic carbon content of freshly emitted sea spray aerosol was similar in all regions sampled, despite significant differences in seawater chlorophyll a levels. The proportion of freshly emitted aerosols that served as cloud condensation nuclei at a given supersaturation was also similar across sampling sites. The large reservoir of organic carbon in surface sea water remained relatively constant across the regions sampled, and independent of variations in chlorophyll a concentrations. We suggest that this reservoir is responsible for the organic carbon enrichment of freshly emitted sea spray aerosol, overwhelming any influence of local biological activity as measured by chlorophyll a levels.

  3. Fluid and electromagnetic transport in sea ice

    NASA Astrophysics Data System (ADS)

    Gully, Adam Spence

    Covering 7-10% of the Earth's ocean surface, sea ice is both an indicator and agent of climate change. The sea ice cover controls the exchange of heat, momentum, and gases between the ocean and atmosphere. As a material, sea ice is a polycrystalline composite consisting of a pure ice host containing brine, air, and solid salt inclusions. This dissertation examines sea ice processes that are important to climate studies. In particular, we investigate the fluid transport properties of sea ice, which mediate melt pond evolution and ice pack reflectance, snow-ice formation, nutrient replenishment for microbial communities, and the evolution of salinity profiles. We also examine the electromagnetic monitoring of these processes, which rely on some knowledge of the effective electrical properties of sea ice. Columnar sea ice is effectively impermeable to fluid flow below a 5% brine volume fraction, yet is permeable for brine volume fractions above this threshold value. In two different experiments conducted in the Arctic and Antarctic, we have found that this critical transition in fluid flow at the brine connectivity threshold displays a strong electrical signature. The sea ice conductivity data are accurately explained by percolation theory with a universal critical exponent of 2. The data also indicate marked changes in the conductivity profile with the onset of surface ponding. Further, resistance data from classical four-probe Wenner arrays on the surfaces of ice floes in Antarctica were used to indirectly reconstruct the conductivity profiles with depth, involving both the horizontal and vertical components. We note the close agreement with the actual data for some models and the inadequacy of others. Additionally, a network model for the electrical conductivity of sea ice is developed, which incorporates statistical measurements of the brine microstructure. The numerical simulations are in close agreement with direct measurements we made in Antarctica on the vertical conductivity of first year sea ice. Together, these results lay the foundation for electromagnetic monitoring of transport phenomena in sea ice and help provide a rigorous basis for electromagnetic methods to obtain sea ice thickness data. We also modify traditional percolation models for columnar sea ice, hypothesizing that granular sea ice has a percolation threshold near a 10% brine volume fraction. This modified percolation model is then in excellent agreement with our fluid permeability field data taken in Antarctica, where granular ice is a significant component of the ice cover. Here we also develop theoretical bounds on two extensive sets of effective complex permittivity sea ice data taken in the Arctic and Antarctic. The first set of bounds assumes only knowledge of the brine volume fraction or porosity, and the second set further assumes statistical isotropy of the microstructure. We obtain excellent agreement between theory and experiment, and are able to observe the apparent violation of the isotropic bounds as the vertically oriented microstructure becomes increasingly connected for higher porosities. Moreover, these bounds are inverted to obtain estimates of the porosity from the measurements of the effective complex permittivity. We find that the temporal variations of the reconstructed porosity, which is directly related to temperature, closely follow the actual behavior. Additionally, an analytic method for obtaining bounds on the effective complex permittivity of polycrystalline composite materials is developed and applied to the effective complex permittivity of sea ice. Here we use mean single crystal orientation data and single crystal complex permittivity tensor data to obtain polycrystalline forward bounds for sea ice. The single crystal complex permittivity tensor is obtained by evaluating X-ray CT data of sea ice with known ice and brine permittivites and brine volume fraction using Comsol 3.5a. Further, inverse bounds are developed and the mean single crystal orientation can be bounded from measurements of the effective complex permittivity tensor. This inverse approach helps lay the groundwork for determining ice type using remote sensing techniques.

  4. Solar radiation interactions with seasonal sea ice

    NASA Astrophysics Data System (ADS)

    Ehn, Jens Kristian

    Presently, the Arctic Ocean is undergoing an escalating reduction in sea ice and a transition towards a seasonal sea ice environment. This warrants detailed investigations into improving our understanding of the seasonal evolution of sea ice and snow covers, and their representation in climate models. The interaction of solar radiation with sea ice is an important process influencing the energy balance and biological activity in polar seas, and consequently plays a key role in the earth's climate system. This thesis focuses on characterization of the optical properties---and the underlying physical properties that determine them---of seasonal sea ice during the fall freeze-up and the spring melt periods. Both periods display high spatial heterogeneity and rapid temporal changes in sea ice properties, and are therefore poorly understood. Field data were collected in Amundsen Gulf/Franklin Bay (FB), southern-eastern Beaufort Sea, in Oct.-Nov. 2003 and Apr. 2004 and in Button Bay (BB), western Hudson Bay, in Mar.-May 2005 to address (1) the temporal and spatial evolution of surface albedo and transmittance, (2) how radiative transfer in sea ice is controlled by its physical nature, and (3) the characteristics of the bottom ice algae community and its effect on the optical properties. The fall study showed the importance of surface features such as dry or slushy bare ice, frost flowers and snow cover in determining the surface albedo. Ice thickness was also important, however, mostly because surface features were associated with thickness. For example, nilas (<10 cm thick) was typically not covered by a snow layer as snow grains were dissolved or merged with the salty and warm brine skim layer on the surface, while surface conditions on thicker ice types were cold and dry enough to support a snow cover. In general, the surface albedo increased exponentially with an ice thickness increase, however, variability within ice thickness types were very large. It is apparent that a more complete treatment of brine movement towards the surface ice of the ice cover and the formation of surface features---such as frost flowers or slush layers---is required to understand the albedo of newly formed sea ice. The sea ice had reached its maximum thickness by late April in both FB and BB (˜1.8 m vs. 1.5-1.7 m). However, surface conditions differed notably as surface melting had not been initiated in FB, while melting had progressed to an advanced stage in BB, illustrating the difference in climate between the two regions (Arctic vs. sub-Arctic). The shortwave partitioning between the atmosphere, sea ice and the ocean---as well as within the sea ice---was strongly affected by diurnal freeze-thaw processes and synoptic weather events that controlled the optical characteristics of the surface. In spring, in situ measurements with a high vertical resolution were conducted within the bottom sea ice layers. The optical properties were strongly affected by ice algae present in the bottom few centimeters. Particulate absorption decreased quickly within the ice above the living algae layer, and showed characteristics of detrital matter. The optical properties for the bottom layers of the sea ice were found to significantly differ from interior ice. This is expected as the bottom ice is very porous and has a lamellar platelet structure, in addition to containing high concentrations of biological matter. These findings emphasize the importance of processes occurring near the surface and bottom boundaries in determining radiative transfer in sea ice covers. Ultimately, a focus on linking numerous aspects of sea ice physics and biology is required in order to predict the seasonal evolution of the sea ice cover in a changing climate.

  5. Putting SEA in context: A discourse perspective on how SEA contributes to decision-making

    SciTech Connect

    Runhaar, Hens

    2009-04-15

    Over the last couple of years there is an ongoing debate in the environmental assessment literature about the contribution of Strategic Environmental Assessment (SEA) to public decision-making and how this can be understood and enhanced by better incorporating insights from policy analysis, planning theory and political sciences. By explicitly framing SEA as an element in a process where stakeholders with diverging interests struggle, acceptability of SEA processes and results by stakeholders has become an important element in SEA evaluation. In addition, the importance of other context variables, such as the institutional organisation, and the need for SEA to adapt to this context, is stressed. Thus far, publications in this area have been dealing with the operationalisation of SEA's 'contribution', typologies of roles that SEA can or should play in different policy settings and on factors that stimulate or impede SEA to play these roles. In this paper an alternative approach is suggested that starts from the deliberative processes around a particular policy issue or decision supported by SEA. Of particular interest are 'discourses': the frames through which groups of actors give meaning to aspects of the policy issues and decisions that are supported by SEA. Discourses do not only reflect conflicts of interests and power play, but also the ways in which actors perceive and understand aspects of the world. Decision-making is conceptualised as a 'system of competing discourse coalitions and their struggles to 'control shared meanings' and to gain acceptance of their framing of a policy issue' [Durning D. A review of Fischer and Forrester (1993) The argumentative turn in policy analysis and planning. Policy Sci 1995;28(1):102-8]. SEA is one of the events in this process that may impact upon dominant discourses. Discourse analysis allows for an understanding of arguments that are considered legitimate for (not) incorporating particular elements of SEA. In addition it opens the door to relatively new strategies for SEA professionals to enhance their contribution to decision-making.

  6. The Antarctic sea ice concentration budget of an ocean-sea ice coupled model

    NASA Astrophysics Data System (ADS)

    Lecomte, Olivier; Goosse, Hugues; Fichefet, Thierry; Holland, Paul R.; Uotila, Petteri

    2015-04-01

    The Antarctic sea ice concentration budget of the NEMO-LIM ocean-sea ice coupled model is computed and analyzed. Following a previously developed method, the sea ice concentration balance over the autumn-winter seasons is decomposed into four terms, including the sea ice concentration change during the period of interest, advection, divergence and a residual accounting for the net contribution of thermodynamics and ice deformation. Preliminary results from this analysis show that the geographical patterns of all budget terms over 1992-2010 are in qualitative agreement with the observed ones. Sea ice thermodynamic growth is maintained by horizontal divergence near the continent and in the central ice pack, while melting close to the ice edge is led by sea ice advection. Quantitatively however, the inner ice pack divergence and associated sea ice freezing are much stronger, as compared to observations. The advection of sea ice in both the central pack and the marginal areas are likewise stronger, which corroborates the findings of a previous study in which the same methods were applied to a fully coupled climate model. Nonetheless, the seasonal evolution of sea ice area and total extent are reasonably well simulated, since enhanced sea ice freezing due to larger divergence in the central pack is compensated by intensified melting in the outer pack owing to faster advection. Those strong dynamic components in the sea ice concentration budget are due to ice velocities that tend to be biased high all around Antarctica and particularly near the ice edge. The obtained results show that the applied method is particularly well suited for assessing the skills of an ocean-sea ice coupled model in simulating the seasonal and regional evolution of Antarctic sea ice for the proper physical reasons.

  7. Influence of sea ice on Arctic precipitation.

    PubMed

    Kopec, Ben G; Feng, Xiahong; Michel, Fred A; Posmentier, Eric S

    2016-01-01

    Global climate is influenced by the Arctic hydrologic cycle, which is, in part, regulated by sea ice through its control on evaporation and precipitation. However, the quantitative link between precipitation and sea ice extent is poorly constrained. Here we present observational evidence for the response of precipitation to sea ice reduction and assess the sensitivity of the response. Changes in the proportion of moisture sourced from the Arctic with sea ice change in the Canadian Arctic and Greenland Sea regions over the past two decades are inferred from annually averaged deuterium excess (d-excess) measurements from six sites. Other influences on the Arctic hydrologic cycle, such as the strength of meridional transport, are assessed using the North Atlantic Oscillation index. We find that the independent, direct effect of sea ice on the increase of the percentage of Arctic sourced moisture (or Arctic moisture proportion, AMP) is 18.2 ± 4.6% and 10.8 ± 3.6%/100,000 km(2) sea ice lost for each region, respectively, corresponding to increases of 10.9 ± 2.8% and 2.7 ± 1.1%/1 °C of warming in the vapor source regions. The moisture source changes likely result in increases of precipitation and changes in energy balance, creating significant uncertainty for climate predictions. PMID:26699509

  8. Low Frequency Variations of Relative Sea Level

    NASA Astrophysics Data System (ADS)

    Douglas, B. C.; Miller, L.

    2006-12-01

    Tide gauge records of sea level display variability at all frequencies, including centennial. This variability adversely impacts estimates of sea level rise, especially for records shorter than 50-75 years. Variability of sea level at tide gauge locations on the eastern boundaries of the N. Atlantic and N. Pacific oceans is very significant even for periods > 100 years. The longest records in the N. Atlantic (Brest) and N. Pacific (San Francisco), universally used in estimates of global sea level rise, display very different behavior in the latter half of the 19th century compared to the 20th century. We show that this behavior is closely related to, but not explained by, local sea level pressure at these sites. It is possible that the disparate behavior of sea level between the 19th and 20th centuries is related to ocean basin-scale atmospheric forcing. Examination of other long records in the northern and southern hemispheres reveals in many cases a leveling off of sea level after about 1960.

  9. Decadal stability of Red Sea mangroves

    NASA Astrophysics Data System (ADS)

    Almahasheer, Hanan; Aljowair, Abdulaziz; Duarte, Carlos M.; Irigoien, Xabier

    2016-02-01

    Across the Earth, mangroves play an important role in coastal protection, both as nurseries and carbon sinks. However, due to various human and environmental impacts, the coverage of mangroves is declining on a global scale. The Red Sea is in the northern-most area of the distribution range of mangroves. Little is known about the surface covered by mangroves at this northern limit or about the changes experienced by Red Sea mangroves. We sought to study changes in the coverage of Red Sea mangroves by using multi-temporal Landsat data (1972, 2000 and 2013). Interestingly, our results show that there has been no decline in mangrove stands in the Red Sea but rather a slight increase. The area covered by mangroves is about 69 Km2 along the African shore and 51 Km2 along the Arabian Peninsula shore. From 1972 to 2013, the area covered by mangroves increased by about 0.29% y-1. We conclude that the trend exhibited by Red Sea mangroves departs from the general global decline of mangroves. Along the Red Sea, mangroves expanded by 12% over the 41 years from 1972 to 2013. Losses to Red Sea mangroves, mostly due to coastal development, have been compensated by afforestation projects.

  10. Recent changes in Antarctic Sea Ice.

    PubMed

    Turner, John; Hosking, J Scott; Bracegirdle, Thomas J; Marshall, Gareth J; Phillips, Tony

    2015-07-13

    In contrast to the Arctic, total sea ice extent (SIE) across the Southern Ocean has increased since the late 1970s, with the annual mean increasing at a rate of 186×10(3) km(2) per decade (1.5% per decade; p<0.01) for 1979-2013. However, this overall increase masks larger regional variations, most notably an increase (decrease) over the Ross (Amundsen-Bellingshausen) Sea. Sea ice variability results from changes in atmospheric and oceanic conditions, although the former is thought to be more significant, since there is a high correlation between anomalies in the ice concentration and the near-surface wind field. The Southern Ocean SIE trend is dominated by the increase in the Ross Sea sector, where the SIE is significantly correlated with the depth of the Amundsen Sea Low (ASL), which has deepened since 1979. The depth of the ASL is influenced by a number of external factors, including tropical sea surface temperatures, but the low also has a large locally driven intrinsic variability, suggesting that SIE in these areas is especially variable. Many of the current generation of coupled climate models have difficulty in simulating sea ice. However, output from the better-performing IPCC CMIP5 models suggests that the recent increase in Antarctic SIE may be within the bounds of intrinsic/internal variability. PMID:26032320

  11. Challenges to sea otter recovery and conservation

    USGS Publications Warehouse

    Ballachey, Brenda E.; Bodkin, James L.

    2015-01-01

    Similar to other species that in recent centuries experienced unregulated human exploitation, sea otters were extirpated throughout large portions of their historic range in the North Pacific. For most of the twentieth century, with cessation of the fur trade and because of concerted efforts at conservation, sea otters recovered much of their historic range and abundance. Late in the twentieth century, increased predation by killer whales in southwest Alaska drove sea otter populations to a few percentage points of their prior abundance, and one of the nation’s largest oil spills in south-central Alaska caused the death of several thousand animals and required more than two decades for recovery. In California, entanglement in fishing gear and environmental degradation, among other factors, have contributed to slow growth in sea otter abundance. We discuss the role of density dependence and spatial structuring of populations in reduced rates of sea otter recovery recently detected in the Northeast Pacific, and consider the potential effects of multiple low-level and cumulative threats on sea otter populations. The resilience demonstrated by sea otters over the past century will be tested in upcoming decades as human activities continue to degrade nearshore coastal areas of the North Pacific.

  12. Sea-ice thermodynamics and brine drainage.

    PubMed

    Worster, M Grae; Rees Jones, David W

    2015-07-13

    Significant changes in the state of the Arctic ice cover are occurring. As the summertime extent of sea ice diminishes, the Arctic is increasingly characterized by first-year rather than multi-year ice. It is during the early stages of ice growth that most brine is injected into the oceans, contributing to the buoyancy flux that mediates the thermo-haline circulation. Current operational sea-ice components of climate models often treat brine rejection between sea ice and the ocean similarly to a thermodynamic segregation process, assigning a fixed salinity to the sea ice, typical of multi-year ice. However, brine rejection is a dynamical, buoyancy-driven process and the salinity of sea ice varies significantly during the first growth season. As a result, current operational models may over predict the early brine fluxes from newly formed sea ice, which may have consequences for coupled simulations of the polar oceans. Improvements both in computational power and our understanding of the processes involved have led to the emergence of a new class of sea-ice models that treat brine rejection dynamically and should enhance predictions of the buoyancy forcing of the oceans. PMID:26032321

  13. Severe Storm in the Sea of Azov

    NASA Technical Reports Server (NTRS)

    2007-01-01

    A fierce storm struck both the Black Sea and the Sea of Azov on November 11, 2007. According to news reports, as many as 10 ships either sank or ran aground, one of them an oil tanker. The Russian tanker Volganeft-139 was anchored to the sea floor in the Kerch Strait linking the Black and Azov Seas when 108-kilometer- (67-mile-) per-hour winds tore the ship apart. As of November 12, up to 2,000 metric tons of fuel oil had leaked from the ship. On November 11, 2007, the day the storm struck, the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA's Aqua satellite captured this image of the region. Thick clouds obscure the view of much of the land area, including Ukraine, Belarus, western Russia, and Georgia. Clouds also obscure the Sea of Azov, although skies over the Black Sea are somewhat clearer. Over the Sea of Azov and immediately to the north, the clouds form a vague swirling pattern, suggestive of a low-pressure cyclonic system.

  14. New Coccolithophore Bloom in Bering Sea

    NASA Technical Reports Server (NTRS)

    2002-01-01

    For the fourth year in a row it appears as if there is a bloom of coccolithophores-marine single-celled plants with calcite scales-in the Bering Sea off the coast of Alaska. Similar blooms were rare before 1997, but they have appeared every year since then. Scientists believe the coccolithophore blooms are the result of changing wind patterns in the region. Weaker than normal winds fail to mix the water of the Bering Sea, resulting in the growth of coccolithophores instead of other types of phytoplankton. Seabird populations have also been changing as a result of this climate change. The Sea-Viewing Wide Field-of-View Sensor (SeaWiFS), flying aboard the OrbView-2 satellite, saw the coccolith-brightened waters of the Bering Sea in 1997, 1998, and 1999. The waters have looked fairly bright again this winter and spring, as seen in this SeaWiFS image acquired April 29, 2000. But scientists are unsure whether this year's phenomenon is caused by living coccolithophorids, re-suspended coccoliths, or something else. Like all phytoplankton, coccolithophores contain chlorophyll and have the tendency to multiply rapidly near the surface. Yet, in large numbers, coccolithophores periodically shed their tiny scales, called 'coccoliths,' by the bucketful into the surrounding waters. The calcium-rich coccoliths turn the normally dark water a bright, milky aquamarine, making coccolithophore blooms easy to spot in satellite imagery. The edge of the whitish cloud in the water seen in this image is roughly 50 kilometers off the West Coast of Alaska. For more information see: SeaWiFS home page Changing Currents Color the Bering Sea a New Shade of Blue Image courtesy SeaWiFS project

  15. Habitats of North American sea ducks.

    USGS Publications Warehouse

    Derksen, Dirk V.; Petersen, Margaret R.; Savard, Jean-Pierre L.

    2015-01-01

    Breeding, molting, fall and spring staging, and wintering habitats of the sea duck tribe Mergini are described based on geographic locations and distribution in North America, geomorphology, vegetation and soil types, and fresh water and marine characteristics. The dynamics of habitats are discussed in light of natural and anthropogenic events that shape areas important to sea ducks. Strategies for sea duck habitat management are outlined and recommendations for international collaboration to preserve key terrestrial and aquatic habitats are advanced. We follow the definition of habitat advanced by Odum (1971), which is the place or space where an organism lives. Weller (1999) emphasized that habitats for waterbirds required presence of sufficient resources (i.e., food, water, cover, space) for maintenance during a portion of their annual cycle. Habitats exploited by North American sea ducks are diverse, widespread across the continent and adjacent marine waters and until recently, most were only superficially known. Even following a 15-year-long effort through the Sea Duck Joint Venture and U.S. and Canadian Endangered/Threatened Species programs to fund research focused on sea duck habitats there are still important gaps in our understanding of key elements required by some species during various life stages. Importantly, many significant habitats, especially staging and wintering sites, have been and continue to be destroyed or altered, largely as a result of anthropogenic effects. Our goal here is to develop a comprehensive summary of marine, freshwater, and terrestrial habitats and their characteristics by considering sea duck species with similar needs as groups (e.g., eiders) within the tribe Mergini. Additionally, this chapter will examine threats and changes to sea duck habitats from human-caused and natural events. Finally, we will evaluate conservation and management programs underway or available for maintenance and enhancement of habitats critical for sea ducks.

  16. Sea level changes: observations versus models

    NASA Astrophysics Data System (ADS)

    Mörner, N.-A.

    2003-04-01

    Sea level rose for glacial eustatic reasons up to about 5000 BP. After that, global sea level has been dominated by the redistribution of ocean water masses (and by that ocean-stored heat). This redistribution of water masses is driven by the interchange of angular momentum between the solid earth and the hydrosphere (in feedback coupling) primarily expressed as changes in the oceanic surface current systems. In view of this, there has been very hard to define any global eustatic signal. This is where and why a dialectic between models and observations enter the sea level debate. According to the glacial loading models, global sea level is now rising by 2.4 mm/year or 1.8 mm/year. The IPCC models have hypothesised of a very rapid rise in the near future, ranging for original wild estimates of 1-3 m in a century to the presently advocated value of 47 +37 mm in a century. The INQUA Commission on Sea Level Changes and Coastal Evolution (www.pog.su.se/sea) hosts the true world specialists on sea level research. This commission has presented an observationally based analysis of the present sea level changes and the changes to be expected in the next century. Both the glacial loading models and the ICPP scenarios are strongly contradicted by observational data for the last 100-150 years that cannot have exceeded a mean rate of 1.0-1.1 mm/year. In the last 300 years, sea level has been oscillation close to the present with peak rates in the period 1890-1930. Sea level fell between 1930 and 1950. The late 20th century lacks any sign of acceleration. Satellite altimetry indicates virtually no changes in the last decade. Therefore, observationally based predictions of future sea level in the year 2100 will give a value of +10 +10 cm (or +5 +15 cm), by this discarding model out-puts by IPCC as well as global loading models. On a regional scale, the Maldives research project has revealed that there are absolutely no signs what so ever on any on-going flooding of the Maldives. On the contrary, a distinct sea level fall is recorded at ~1970. In conclusions, there are firm observationally based reasons to free the world from the condemnation to become extensively flooded in the 21st century AD.

  17. District cooling in Stockholm using sea water

    SciTech Connect

    Fermbaeck, G.

    1995-12-31

    In May this year Stockholm Energi started supplying properties in central Stockholm with cooling for comfort and for various processes from its new district cooling system. The project is unique in that most of the cooling energy is produced using cold water from the Baltic Sea. The following article describes the system and provides a summary of the considerations that resulted in venturing to invest in sea-water cooling for such a large project. There is also a description of the hydrological conditions that made the system feasible in Stockholm and some speculations about the possibilities to use cooled sea water elsewhere in the world.

  18. Common Era Sea-Level Change

    NASA Astrophysics Data System (ADS)

    Horton, B.; Kemp, A.; Kopp, R. E., III

    2014-12-01

    The Atlantic coast of North America provides a sedimentary record of Common Era sea levels with the resolution to identify the mechanisms that cause spatial variability in sea-level rise. This coast has a small tidal range, improving the precision of sea-level reconstructions. Coastal subsidence (from glacial isostatic adjustment, GIA) creates accommodation space that is filled by salt-marsh peat and preserves accurate and precise sea-level indicators and abundant material for radiocarbon dating. In addition, the western North Atlantic Ocean is sensitive to spatial variability in sea-level change, because of static equilibrium effects from melting of the Greenland Ice Sheet, ocean circulation and wind-driven variability in the Gulf Stream and GIA induced land-level change from ongoing collapse of Laurentide forbuldge. We reveal three distinct patters in sea-level during the Common Era along the North American Atlantic coast, likely linked to wind-driven changes in the Gulf Stream: (1) Florida, sea level is essentially flat, with the record dominated by long-term geological processes; (2) North Carolina, sea level falls to a minimum near the beginning of the second millennium, climbing to an early Little Ice Age maximum in the fifteenth century, and then declining through most of the nineteenth century; and (3) New Jersey, a sea-level maximum around 900 CE, a sea-level minimum around 1500 CE, and a long-term sea-level rise through the second half of the second millennium. We combine the salt-marsh data from North American Atlantic coast with tide-gauge records and lower resolution proxies from the northern and southern hemispheres. We apply a noisy-input Gaussian process spatio-temporal modeling framework, which identifies a long-term falling global mean sea-level (GMSL), interrupted in the middle of the 19th century by an acceleration yielding a 20th century rate of rise extremely likely (probability P = 0:95) faster than any previous century in the Common Era.

  19. Sea Ice, Climate and Fram Strait

    NASA Technical Reports Server (NTRS)

    Hunkins, K.

    1984-01-01

    When sea ice is formed the albedo of the ocean surface increases from its open water value of about 0.1 to a value as high as 0.8. This albedo change effects the radiation balance and thus has the potential to alter climate. Sea ice also partially seals off the ocean from the atmosphere, reducing the exchange of gases such as carbon dioxide. This is another possible mechanism by which climate might be affected. The Marginal Ice Zone Experiment (MIZEX 83 to 84) is an international, multidisciplinary study of processes controlling the edge of the ice pack in that area including the interactions between sea, air and ice.

  20. Microseisms and sea wave height in the Ligurian Sea: a preliminary analysis.

    NASA Astrophysics Data System (ADS)

    Zunino, A.; Ferretti, G.; Scafidi, D.; Barani, S.; Pasta, M.; Spallarossa, D.

    2012-04-01

    Analysis of the relationship between microseisms and sea wave heights is a fundamental step for understanding the interaction of sea storms with near coastal environment, as well as to gain insights about the possibility of forecasting sea wave heights from microseism. The possibility to predict sea wave heights in the Ligurian Sea is analyzed in this study using about a month of observations from both seismic recordings from a near-coast station (IMI - Imperia Monte Faudo) and significant sea wave heights measured from a buoy (Côte d'Azur buoy, Météo-France network). We focus on the analysis of the vertical component of microseism, which reveals a strong correlation with measured sea wave heights. Looking at the amplitude spectrogram of the vertical component of microseism, we recognize the effects of several meteo-marine events that can be ascribed to Atlantic barometric pressure lows and a series of sea storms in the Ligurian Sea. Moreover, the distinction between primary and secondary microseism is inferred from the spectrogram, even if, because of the superposition of Atlantic and Ligurian effects, it sometimes results difficult. Analysis of microseism polarization reveals a double origin which determines two prevailing orientations, corresponding to Atlantic and Ligurian meteo-marine phenomena. We feature the spectral properties of microseism making a close correlation among (1) the power spectral density spectrum of microseism, (2) the significant sea wave heights measured from the buoy and (3) sea storms occurred in the period under study, showing that there is a good correlation between spectral energy content of microseism and sea wave height. Finally, in order to set up a predictive law, we solve an inverse problem to find the optimal parameters that allow us to estimate the sea wave height given the vertical component of microseism. Specifically, the application of the definition of significant height wave height for the microseism needs the determination of some unknowns that, in our case, are sought employing a Monte Carlo Markov chain method. The resulting predictive law is based on the definition of significant sea wave height modified to account for the characteristics (both amplitude and frequency content) of microseism. Our simple predictive law demonstrates a good ability to reproduce the observed sea wave heights. This work represents a first step aiming at assessing the possibility of predicting significant sea wave height in the Ligurian Sea.

  1. What Can Sea Ice Reconstructions Tell Us About Recent Regional Trends in Sea Ice Around Antarctica?

    NASA Astrophysics Data System (ADS)

    Abram, N.; Mulvaney, R.; Murphy, E. J.

    2014-12-01

    Satellite observations of recent sea ice changes around Antarctica reveal regionally heterogeneous trends, but with an overall increasing trend in Antarctic-wide sea ice extent. Proposed mechanisms to account for increasing sea ice extent around Antarctica include freshening of the ocean surface due to melting of land ice and northward wind drift associated with strengthening of the Southern Ocean westerly winds. In this study we use extended, regional reconstructions of Antarctic sea ice changes from ice core chemistry and reanalysis of the South Orkney fast ice series to examine long-term relationships between Antarctic regional sea ice changes and surface winds. The formation and breakout of fast ice at the South Orkney islands (Murphy et al., 2014) indicates that westerly wind strength is an important factor in determining spring sea ice retreat in the Weddell Sea region. In contrast, autumn sea ice formation is more strongly influenced by long-lived ocean temperature anomalies and sea ice migration from the previous year, highlighting the multiple influences that act at different times of the year to determine the overall extent of winter sea ice. To assess the hypothesized role of westerly wind changes in driving opposing patterns of recent sea ice change between the Ross Sea and Bellingshausen Sea, we also present a comparison of ice core MSA evidence for sea ice changes derived from the James Ross Island (Mulvaney et al., 2012) and Erebus Saddle (Rhodes et al., 2012) ice cores, and view this in the context of trends in the Southern Annular Mode (Abram et al., 2014) over the last 200 years. References: Abram et al., 2014. Evolution of the Southern Annular Mode over the past millennium. Nature Climate Change. doi: 10.1038/nclimate2235 Mulvaney et al., 2012. Recent Antarctic Peninsula warming relative to Holocene temperature and ice-shelf history. Nature. doi: 10.1038/nature11391 Murphy et al., 2014. Variability of sea ice in the northern Weddell Sea during the 20th century. Journal of Geophysical Research. doi: 10.1002/2013JC009511 Rhodes et al., 2012. Little Ice Age climate and oceanic conditions of the Ross Sea, Antarctica, from a coastal ice core record. Climate of the Past. doi: 10.5194/cp-8-1223-2012

  2. Does Arctic sea ice reduction foster shelf-basin exchange?

    PubMed

    Ivanov, Vladimir; Watanabe, Eiji

    2013-12-01

    The recent shift in Arctic ice conditions from prevailing multi-year ice to first-year ice will presumably intensify fall-winter sea ice freezing and the associated salt flux to the underlying water column. Here, we conduct a dual modeling study whose results suggest that the predicted catastrophic consequences for the global thermohaline circulation (THC), as a result of the disappearance of Arctic sea ice, may not necessarily occur. In a warmer climate, the substantial fraction of dense water feeding the Greenland-Scotland overflow may form on Arctic shelves and cascade to the deep basin, thus replenishing dense water, which currently forms through open ocean convection in the sub-Arctic seas. We have used a simplified model for estimating how increased ice production influences shelf-basin exchange associated with dense water cascading. We have carried out case studies in two regions of the Arctic Ocean where cascading was observed in the past. The baseline range of buoyancy-forcing derived from the columnar ice formation was calculated as part of a 30-year experiment of the pan-Arctic coupled ice-ocean general circulation model (GCM). The GCM results indicate that mechanical sea ice divergence associated with lateral advection accounts for a significant part of the interannual variations in sea ice thermal production in the coastal polynya regions. This forcing was then rectified by taking into account sub-grid processes and used in a regional model with analytically prescribed bottom topography and vertical stratification in order to examine specific cascading conditions in the Pacific and Atlantic sectors of the Arctic Ocean. Our results demonstrate that the consequences of enhanced ice formation depend on geographical location and shelf-basin bathymetry. In the Pacific sector, strong density stratification in slope waters impedes noticeable deepening of shelf-origin water, even for the strongest forcing applied. In the Atlantic sector, a 1.5x increase of salt flux leads to a threefold increase of shelf-slope volume flux below the warm core of Atlantic water. This threefold increase would be a sufficient substitute for a similar amount of dense water that currently forms in the Greenland, Iceland, and Norwegian (GIN) seas but is expected to decrease in a warming climate. PMID:24555308

  3. Effects of Mackenzie River Discharge and Bathymetry on Sea Ice in the Beaufort Sea

    NASA Technical Reports Server (NTRS)

    Nghiem, S. V.; Hall, D. K.; Rigor, I. G; Li, P.; Neumann, G.

    2014-01-01

    Mackenzie River discharge and bathymetry effects on sea ice in the Beaufort Sea are examined in 2012 when Arctic sea ice extent hit a record low. Satellite-derived sea surface temperature revealed warmer waters closer to river mouths. By 5 July 2012, Mackenzie warm waters occupied most of an open water area about 316,000 sq km. Surface temperature in a common open water area increased by 6.5 C between 14 June and 5 July 2012, before and after the river waters broke through a recurrent landfast ice barrier formed over the shallow seafloor offshore the Mackenzie Delta. In 2012, melting by warm river waters was especially effective when the strong Beaufort Gyre fragmented sea ice into unconsolidated floes. The Mackenzie and other large rivers can transport an enormous amount of heat across immense continental watersheds into the Arctic Ocean, constituting a stark contrast to the Antarctic that has no such rivers to affect sea ice.

  4. Phylogenetic Relationships among Deep-Sea and Chemosynthetic Sea Anemones: Actinoscyphiidae and Actinostolidae (Actiniaria: Mesomyaria)

    PubMed Central

    Rodríguez, Estefanía; Daly, Marymegan

    2010-01-01

    Sea anemones (Cnidaria, Actiniaria) are present in all marine ecosystems, including chemosynthetic environments. The high level of endemicity of sea anemones in chemosynthetic environments and the taxonomic confusion in many of the groups to which these animals belong makes their systematic relationships obscure. We use five molecular markers to explore the phylogenetic relationships of the superfamily Mesomyaria, which includes most of the species that live in chemosynthetic, deep-sea, and polar sea habitats and to test the monophyly of the recently defined clades Actinostolina and Chemosynthina. We found that sea anemones of chemosynthetic environments derive from at least two different lineages: one lineage including acontiate deep-sea taxa and the other primarily encompassing shallow-water taxa. PMID:20532040

  5. Coccoliths in the Celtic Sea

    NASA Technical Reports Server (NTRS)

    2002-01-01

    As the basis of the marine food chain, phytoplankton are important indicators of change in the oceans. These marine flora also extract carbon dioxide from the atmosphere for use in photosynthesis, and play an important role in global climate. Phytoplankton blooms that occur near the surface are readily visible from space, enabling a global estimation of the presence of chlorophyll and other pigments. There are more than 5,000 different species of phytoplankton however, and it is not always possible to identify the type of phytoplankton present using space-based remote sensing.

    Coccolithophores, however, are a group of phytoplankton that are identifiable from space. These microscopic plants armor themselves with external plates of calcium carbonate. The plates, or coccoliths, give the ocean a milky white or turquoise appearance during intense blooms. The long-term flux of coccoliths to the ocean floor is the main process responsible for the formation of chalk and limestone.

    This image is a natural-color view of the Celtic Sea and English Channel regions, and was acquired by the Multi-angle Imaging SpectroRadiometer's nadir (vertical-viewing) camera on June 4, 2001 during Terra orbit 7778. It represents an area of 380 kilometers x 445 kilometers, and includes portions of southwestern England and northwestern France. The coccolithophore bloom in the lower left-hand corner usually occurs in the Celtic Sea for several weeks in summer. The coccoliths backscatter light from the water column to create a bright optical effect. Other algal and/or phytoplankton blooms can also be discerned along the coasts near Portsmouth, England and Granville, France.

    At full resolution, evidence of human activity is also apparent in this image. White specks associated with ship wakes are present in the open water, and aircraft contrails are visible within the high cirrus clouds over the English Channel.

    MISR was built and is managed by NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Office of Earth Science, Washington, DC. The Terra satellite is managed by NASA's Goddard Space Flight Center, Greenbelt, MD. JPL is a division of the California Institute of Technology.

  6. Increased Land Use by Chukchi Sea Polar Bears in Relation to Changing Sea Ice Conditions

    PubMed Central

    Rode, Karyn D.; Wilson, Ryan R.; Regehr, Eric V.; St. Martin, Michelle; Douglas, David C.; Olson, Jay

    2015-01-01

    Recent observations suggest that polar bears (Ursus maritimus) are increasingly using land habitats in some parts of their range, where they have minimal access to their preferred prey, likely in response to loss of their sea ice habitat associated with climatic warming. We used location data from female polar bears fit with satellite radio collars to compare land use patterns in the Chukchi Sea between two periods (1986–1995 and 2008–2013) when substantial summer sea-ice loss occurred. In both time periods, polar bears predominantly occupied sea-ice, although land was used during the summer sea-ice retreat and during the winter for maternal denning. However, the proportion of bears on land for > 7 days between August and October increased between the two periods from 20.0% to 38.9%, and the average duration on land increased by 30 days. The majority of bears that used land in the summer and for denning came to Wrangel and Herald Islands (Russia), highlighting the importance of these northernmost land habitats to Chukchi Sea polar bears. Where bears summered and denned, and how long they spent there, was related to the timing and duration of sea ice retreat. Our results are consistent with other studies supporting increased land use as a common response of polar bears to sea-ice loss. Implications of increased land use for Chukchi Sea polar bears are unclear, because a recent study observed no change in body condition or reproductive indices between the two periods considered here. This result suggests that the ecology of this region may provide a degree of resilience to sea ice loss. However, projections of continued sea ice loss suggest that polar bears in the Chukchi Sea and other parts of the Arctic may increasingly use land habitats in the future, which has the potential to increase nutritional stress and human-polar bear interactions. PMID:26580809

  7. Walrus areas of use in the Chukchi Sea during sparse sea ice cover

    USGS Publications Warehouse

    Jay, Chadwick V.; Fischbach, Anthony S.; Kochnev, Anatoly A.

    2012-01-01

    The Pacific walrus Odobenus rosmarus divergens feeds on benthic invertebrates on the continental shelf of the Chukchi and Bering Seas and rests on sea ice between foraging trips. With climate warming, ice-free periods in the Chukchi Sea have increased and are projected to increase further in frequency and duration. We radio-tracked walruses to estimate areas of walrus foraging and occupancy in the Chukchi Sea from June to November of 2008 to 2011, years when sea ice was sparse over the continental shelf in comparison to historical records. The earlier and more extensive sea ice retreat in June to September, and delayed freeze-up of sea ice in October to November, created conditions for walruses to arrive earlier and stay later in the Chukchi Sea than in the past. The lack of sea ice over the continental shelf from September to October caused walruses to forage in nearshore areas instead of offshore areas as in the past. Walruses did not frequent the deep waters of the Arctic Basin when sea ice retreated off the shelf. Walruses foraged in most areas they occupied, and areas of concentrated foraging generally corresponded to regions of high benthic biomass, such as in the northeastern (Hanna Shoal) and southwestern Chukchi Sea. A notable exception was the occurrence of concentrated foraging in a nearshore area of northwestern Alaska that is apparently depauperate in walrus prey. With increasing sea ice loss, it is likely that walruses will increase their use of coastal haul-outs and nearshore foraging areas, with consequences to the population that are yet to be understood.

  8. Increased Land Use by Chukchi Sea Polar Bears in Relation to Changing Sea Ice Conditions.

    PubMed

    Rode, Karyn D; Wilson, Ryan R; Regehr, Eric V; St Martin, Michelle; Douglas, David C; Olson, Jay

    2015-01-01

    Recent observations suggest that polar bears (Ursus maritimus) are increasingly using land habitats in some parts of their range, where they have minimal access to their preferred prey, likely in response to loss of their sea ice habitat associated with climatic warming. We used location data from female polar bears fit with satellite radio collars to compare land use patterns in the Chukchi Sea between two periods (1986-1995 and 2008-2013) when substantial summer sea-ice loss occurred. In both time periods, polar bears predominantly occupied sea-ice, although land was used during the summer sea-ice retreat and during the winter for maternal denning. However, the proportion of bears on land for > 7 days between August and October increased between the two periods from 20.0% to 38.9%, and the average duration on land increased by 30 days. The majority of bears that used land in the summer and for denning came to Wrangel and Herald Islands (Russia), highlighting the importance of these northernmost land habitats to Chukchi Sea polar bears. Where bears summered and denned, and how long they spent there, was related to the timing and duration of sea ice retreat. Our results are consistent with other studies supporting increased land use as a common response of polar bears to sea-ice loss. Implications of increased land use for Chukchi Sea polar bears are unclear, because a recent study observed no change in body condition or reproductive indices between the two periods considered here. This result suggests that the ecology of this region may provide a degree of resilience to sea ice loss. However, projections of continued sea ice loss suggest that polar bears in the Chukchi Sea and other parts of the Arctic may increasingly use land habitats in the future, which has the potential to increase nutritional stress and human-polar bear interactions. PMID:26580809

  9. Increased land use by Chukchi Sea polar bears in relation to changing sea ice conditions

    USGS Publications Warehouse

    Rode, Karyn D.; Wilson, Ryan R.; Regehr, Eric V.; St. Martin, Michelle; Douglas, David; Olson, Jay

    2015-01-01

    Recent observations suggest that polar bears (Ursus maritimus) are increasingly using land habitats in some parts of their range, where they have minimal access to their preferred prey, likely in response to loss of their sea ice habitat associated with climatic warming. We used location data from female polar bears fit with satellite radio collars to compare land use patterns in the Chukchi Sea between two periods (1986–1995 and 2008–2013) when substantial summer sea-ice loss occurred. In both time periods, polar bears predominantly occupied sea-ice, although land was used during the summer sea-ice retreat and during the winter for maternal denning. However, the proportion of bears on land for > 7 days between August and October increased between the two periods from 20.0% to 38.9%, and the average duration on land increased by 30 days. The majority of bears that used land in the summer and for denning came to Wrangel and Herald Islands (Russia), highlighting the importance of these northernmost land habitats to Chukchi Sea polar bears. Where bears summered and denned, and how long they spent there, was related to the timing and duration of sea ice retreat. Our results are consistent with other studies supporting increased land use as a common response of polar bears to sea-ice loss. Implications of increased land use for Chukchi Sea polar bears are unclear, because a recent study observed no change in body condition or reproductive indices between the two periods considered here. This result suggests that the ecology of this region may provide a degree of resilience to sea ice loss. However, projections of continued sea ice loss suggest that polar bears in the Chukchi Sea and other parts of the Arctic may increasingly use land habitats in the future, which has the potential to increase nutritional stress and human-polar bear interactions.

  10. Sea-level variability in the Mediterranean Sea from altimetry and tide gauges

    NASA Astrophysics Data System (ADS)

    Bonaduce, A.; Pinardi, N.; Oddo, P.; Spada, G.; Larnicol, G.

    2016-02-01

    Sea-level variability in the Mediterranean Sea was investigated by means of in-situ (tide-gauge) and satellite altimetry data over a period spanning two decades (from 1993 to 2012). The paper details the sea-level variations during this time period retrieved from the two data sets. Mean sea-level (MSL) estimates obtained from tide-gauge data showed root mean square differences (RMSDs) in the order of 40-50 % of the variance of the MSL signal estimated from satellite altimetry data, with a dependency on the number and quality of the in-situ data considered. Considering the individual time-series, the results showed that coastal tide-gauge and satellite sea-level signals are comparable, with RMSDs that range between 2.5 and 5 cm and correlation coefficients up to the order of 0.8. A coherence analysis and power spectra comparison showed that two signals have a very similar energetic content at semi-annual temporal scales and below, while a phase drift was observed at higher frequencies. Positive sea-level linear trends for the analysis period were estimated for both the mean sea-level and the coastal stations. From 1993 to 2012, the mean sea-level trend (2.44± 0.5 mm year^{-1} ) was found to be affected by the positive anomalies of 2010 and 2011, which were observed in all the cases analysed and were mainly distributed in the eastern part of the basin. Ensemble empirical mode decomposition showed that these events were related to the processes that have dominant periodicities of ˜ 10 years, and positive residual sea-level trend were generally observed in both data-sets. In terms of mean sea-level trends, a significant positive sea-level trend (> 95 %) in the Mediterranean Sea was found on the basis of at least 15 years of data.

  11. 15 CFR 917.11 - Guidelines for Sea Grant Fellowships.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 15 Commerce and Foreign Trade 3 2012-01-01 2012-01-01 false Guidelines for Sea Grant Fellowships... Sea Grant Fellowships. (a) Sea Grant Fellowships are designed to provide educational and training... applications for Sea Grant Fellowship funding. (b) Funding will be made to eligible entities (see § 917.10...

  12. 15 CFR 917.11 - Guidelines for Sea Grant Fellowships.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 15 Commerce and Foreign Trade 3 2011-01-01 2011-01-01 false Guidelines for Sea Grant Fellowships... Sea Grant Fellowships. (a) Sea Grant Fellowships are designed to provide educational and training... applications for Sea Grant Fellowship funding. (b) Funding will be made to eligible entities (see § 917.10...

  13. 15 CFR 917.11 - Guidelines for Sea Grant Fellowships.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 15 Commerce and Foreign Trade 3 2013-01-01 2013-01-01 false Guidelines for Sea Grant Fellowships... Sea Grant Fellowships. (a) Sea Grant Fellowships are designed to provide educational and training... applications for Sea Grant Fellowship funding. (b) Funding will be made to eligible entities (see § 917.10...

  14. 15 CFR 917.11 - Guidelines for Sea Grant Fellowships.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 15 Commerce and Foreign Trade 3 2014-01-01 2014-01-01 false Guidelines for Sea Grant Fellowships... Sea Grant Fellowships. (a) Sea Grant Fellowships are designed to provide educational and training... applications for Sea Grant Fellowship funding. (b) Funding will be made to eligible entities (see § 917.10...

  15. The Secret of the Svalbard Sea Ice Barrier

    NASA Technical Reports Server (NTRS)

    Nghiem, Son V.; Van Woert, Michael L.; Neumann, Gregory

    2004-01-01

    An elongated sea ice feature called the Svalbard sea ice barrier rapidly formed over an area in the Barents Sea to the east of Svalbard posing navigation hazards. The secret of its formation lies in the bottom bathymetry that governs the distribution of cold Arctic waters masses, which impacts sea ice growth on the water surface.

  16. 47 CFR 32.2424 - Submarine & deep sea cable.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 2 2014-10-01 2014-10-01 false Submarine & deep sea cable. 32.2424 Section 32... Submarine & deep sea cable. (a) This account shall include the original cost of submarine cable and deep sea... defined below, are to be maintained for nonmetallic submarine and deep sea cable and metallic...

  17. 47 CFR 32.2424 - Submarine & deep sea cable.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 2 2013-10-01 2013-10-01 false Submarine & deep sea cable. 32.2424 Section 32... Submarine & deep sea cable. (a) This account shall include the original cost of submarine cable and deep sea... defined below, are to be maintained for nonmetallic submarine and deep sea cable and metallic...

  18. 47 CFR 32.2424 - Submarine & deep sea cable.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 2 2010-10-01 2010-10-01 false Submarine & deep sea cable. 32.2424 Section 32... Submarine & deep sea cable. (a) This account shall include the original cost of submarine cable and deep sea... defined below, are to be maintained for nonmetallic submarine and deep sea cable and metallic...

  19. 47 CFR 32.2424 - Submarine & deep sea cable.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 2 2011-10-01 2011-10-01 false Submarine & deep sea cable. 32.2424 Section 32... Submarine & deep sea cable. (a) This account shall include the original cost of submarine cable and deep sea... defined below, are to be maintained for nonmetallic submarine and deep sea cable and metallic...

  20. SIPEX--Exploring the Antarctic Sea Ice Zone

    ERIC Educational Resources Information Center

    Zicus, Sandra; Dobson, Jane; Worby, Anthony

    2008-01-01

    Sea ice in the polar regions plays a key role in both regulating global climate and maintaining marine ecosystems. The international Sea Ice Physics and Ecosystem eXperiment (SIPEX) explored the sea ice zone around Antarctica in September and October 2007, investigating relationships between the physical sea ice environment and the structure of…

  1. Progress Toward Demonstrating SAR Monitoring of Chinese Seas

    NASA Astrophysics Data System (ADS)

    Huang, Weigen; Johannessen, Johnny; Alpers, Werner; Yang, Jingsong

    2010-12-01

    "Demonstrating SAR monitoring of Chinese seas" is a project of the ESA-MOST Dragon 2 program. This paper presents the progress of the project. Retrieval algorithms for SAR monitoring of sea surface currents, oceanic internal waves, sea surface winds, oil spills and ships have been advanced. SAR monitoring of Chinese seas in near-real-time is now in demonstration phase.

  2. SIPEX--Exploring the Antarctic Sea Ice Zone

    ERIC Educational Resources Information Center

    Zicus, Sandra; Dobson, Jane; Worby, Anthony

    2008-01-01

    Sea ice in the polar regions plays a key role in both regulating global climate and maintaining marine ecosystems. The international Sea Ice Physics and Ecosystem eXperiment (SIPEX) explored the sea ice zone around Antarctica in September and October 2007, investigating relationships between the physical sea ice environment and the structure of

  3. 76 FR 16731 - National Sea Grant Advisory Board

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-03-25

    ... National Oceanic and Atmospheric Administration National Sea Grant Advisory Board AGENCY: National Oceanic... National Sea Grant Advisory Board members. SUMMARY: This notice responds to Section 209 of the Sea Grant... to solicit nominations at least once a year for membership on the National Sea Grant Advisory...

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

    USGS Publications Warehouse

    Douglas, D.C.

    2010-01-01

    The Arctic region is warming faster than most regions of the world due in part to increasing greenhouse gases and positive feedbacks associated with the loss of snow and ice cover. One consequence has been a rapid decline in Arctic sea ice over the past 3 decades?a decline that is projected to continue by state-of-the-art models. Many stakeholders are therefore interested in how global warming may change the timing and extent of sea ice Arctic-wide, and for specific regions. To inform the public and decision makers of anticipated environmental changes, scientists are striving to better understand how sea ice influences ecosystem structure, local weather, and global climate. Here, projected changes in the Bering and Chukchi Seas are examined because sea ice influences the presence of, or accessibility to, a variety of local resources of commercial and cultural value. In this study, 21st century sea ice conditions in the Bering and Chukchi Seas are based on projections by 18 general circulation models (GCMs) prepared for the fourth reporting period by the Intergovernmental Panel on Climate Change (IPCC) in 2007. Sea ice projections are analyzed for each of two IPCC greenhouse gas forcing scenarios: the A1B `business as usual? scenario and the A2 scenario that is somewhat more aggressive in its CO2 emissions during the second half of the century. A large spread of uncertainty among projections by all 18 models was constrained by creating model subsets that excluded GCMs that poorly simulated the 1979-2008 satellite record of ice extent and seasonality. At the end of the 21st century (2090-2099), median sea ice projections among all combinations of model ensemble and forcing scenario were qualitatively similar. June is projected to experience the least amount of sea ice loss among all months. For the Chukchi Sea, projections show extensive ice melt during July and ice-free conditions during August, September, and October by the end of the century, with high agreement among models. High agreement also accompanies projections that the Chukchi Sea will be completely ice covered during February, March, and April at the end of the century. Large uncertainties, however, are associated with the timing and amount of partial ice cover during the intervening periods of melt and freeze. For the Bering Sea, median March ice extent is projected to be about 25 percent less than the 1979-1988 average by mid-century and 60 percent less by the end of the century. The ice-free season in the Bering Sea is projected to increase from its contemporary average of 5.5 months to a median of about 8.5 months by the end of the century. A 3-month longer ice- free season in the Bering Sea is attained by a 1-month advance in melt and a 2-month delay in freeze, meaning the ice edge typically will pass through the Bering Strait in May and January at the end of the century rather than June and November as presently observed.

  5. Mission Possible: The Sea Semester Program.

    ERIC Educational Resources Information Center

    Saveland, Robert N.; Stoner, Allan W.

    1985-01-01

    The "Research Vessel Westward" provides a sea-going research laboratory for students from various disciplines to learn oceanography concepts and research techniques while earning university credit. Descriptions of equipment, organizational structure, and student research responsibilities are presented. (DH)

  6. MODIS Snow and Sea Ice Products

    NASA Technical Reports Server (NTRS)

    Hall, Dorothy K.; Riggs, George A.; Salomonson, Vincent V.

    2004-01-01

    In this chapter, we describe the suite of Earth Observing System (EOS) Moderate-Resolution Imaging Spectroradiometer (MODIS) Terra and Aqua snow and sea ice products. Global, daily products, developed at Goddard Space Flight Center, are archived and distributed through the National Snow and Ice Data Center at various resolutions and on different grids useful for different communities Snow products include binary snow cover, snow albedo, and in the near future, fraction of snow in a 5OO-m pixel. Sea ice products include ice extent determined with two different algorithms, and sea ice surface temperature. The algorithms used to develop these products are described. Both the snow and sea ice products, available since February 24,2000, are useful for modelers. Validation of the products is also discussed.

  7. Seismic refraction profile in coral sea basin.

    PubMed

    Shor, G G

    1967-11-17

    A refraction profile near the south edge of Coral Sea Basin shows sediments, "second layer," and oceanic crust all thicker than normal for an oceanic station; normal mantle lies at a depth of 19 kilometers. PMID:17753600

  8. Measurement of light scattering in deep sea

    NASA Astrophysics Data System (ADS)

    Maragos, N.; Balasi, K.; Domvoglou, T.; Kiskiras, I.; Lenis, D.; Maniatis, M.; Stavropoulos, G.

    2016-04-01

    The deep-sea neutrino telescope in the Mediterranean Sea, being prepared by the KM3NET collaboration, will contain thousands of optical sensors to readout. The accurate knowledge of the optical properties of deep-sea water is of great importance for the neutrino event reconstruction process. In this study we describe our progress in designing an experimental setup and studying a method to measure the parameters describing the absorption and scattering characteristics of deep-sea water. Three PMTs will be used to measure in situ the scattered light emitted from six laser diodes in three different wavelengths covering the Cherenkov radiation spectrum. The technique for the evaluation of the parameters is based on Monte Carlo simulations and our results show that we are able to determine these parameters with satisfying precision.

  9. Remote Sensing of the Arctic Seas.

    ERIC Educational Resources Information Center

    Weeks, W. F.; And Others

    1986-01-01

    Examines remote sensing of the arctic seas by discussing: (1) passive microwave sensors; (2) active microwave sensors; (3) other types of sensors; (4) the future deployment of sensors; (5) data buoys; and (6) future endeavors. (JN)

  10. Submarine pingos in the beaufort sea.

    PubMed

    Shearer, J M; Macnab, R F; Pelletier, B R; Smith, T B

    1971-11-19

    Numerous underwater mounds found on the continental shelf of the Beaufort Sea are thought to be pingos (hills that have a central core of ice) which have formed in the marine environment subsequent to oceanic transgression. PMID:17759389

  11. 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. PMID:26013591

  12. USGS and NOAA Monitor Arctic Sea Ice

    USGS scientist Jonathan Childs and NOAA oceanographer Pablo Clemente-Colón, also Chief Scientist of the National Ice Center, looking out on the Arctic sea ice. This was during a scientific expedition to map the Arctic seafloor....

  13. 2011 Sea Ice Minimum - Duration: 61 seconds.

    NASA Video Gallery

    This video shows Arctic sea ice from March 7, 2011, to Sept. 9, 2011, ending with a comparison of the 30-year average minimum extent, shown in yellow, and the Northwest Passage, in red. (no audio) ...

  14. The old man and the sea.

    SciTech Connect

    Geesaman, D. F.

    2010-01-01

    The summary of this presentation is: (1) the origin and structure of the sea remain critical themes in the physics of the nucleon and nucleus; (2) We need to push to higher x values and E906/SeaQuest is especially well suited for this. We start this summer and run for two years; (3) The other really key measurement is improved precision in the spin carried by the sea quarks and the spin-correlations in the sea - COMPASS, RHIC, J-PARC, JLAB 12 GeV.; and (4) This is difficult and may require the next generation of polarized Drell-Yan experiments. Whatever we measure, Tony Thomas will have thought of it first and helped stimulate the experiments.

  15. Groundwater depletion contributes to sea level rise

    NASA Astrophysics Data System (ADS)

    Balcerak, Ernie

    2012-07-01

    Groundwater depletion is contributing substantially to sea level rise and will likely continue to do so over the next several decades, according to a new study by Wada et al. Much of the groundwater extracted for irrigation, drinking, and other uses does not wind up back in the ground but instead evaporates to the atmosphere and then returns to the surface as precipitation, which eventually makes its way to the oceans and leads to sea level rise. The authors reconstructed past groundwater depletion and its contribution to global sea level change and developed new projections for the 21st century based on models. They found that the contribution of groundwater depletion to global sea level increased from 0.035 millimeter per year in 1900 to 0.57 millimeter per year in 2000 and is projected to increase to 0.82 millimeter per year by 2050.

  16. A coupled sea ice-mixed layer-pycnocline model for the Weddell Sea

    SciTech Connect

    Lemke, P. ); Owens, W.B. ); Hibler, W.D. III )

    1990-06-15

    A dynamic-thermodynamic sea ice model is coupled to a one-dimensional model of the oceanic mixed layer and pycnocline and is applied to the Weddell Sea. This model prognostically determines the vertical oceanic heat flux from the mixed layer dynamics in contrast to earlier sea ice modeling where the oceanic heat flux was prescribed. In addition to the standard simulation, polynya and paleoclimate experiments were performed to investigate the effects of sea ice dynamics. Furthermore, the mixed layer-pycnocline model is compared to the original Kraus-Turner approach.

  17. Raising the dead without a Red Sea-Dead Sea canal? Hydro-economics and governance

    NASA Astrophysics Data System (ADS)

    Rosenberg, D. E.

    2010-12-01

    Seven decades of extractions have dramatically reduced Jordan River flows, lowered the Dead Sea level, opened sink holes, and caused other environmental problems. The fix Jordan, Israel, and the Palestinians propose would build an expensive multipurpose canal from the Red Sea to the Dead Sea that would also generate hydropower and desalinated water. This paper compares the Red-Dead project to alternatives that may also raise the Dead Sea level. Hydro-economic model results for the Jordan-Israel-Palestinian inter-tied water systems show two restoration alternatives are more economically viable than the proposed Red-Dead project. Many decentralized new supply, wastewater reuse, conveyance, conservation, and leak reduction projects and programs in each country can together increase economic benefits and reliably deliver up to 900 MCM/year to the Dead Sea. Similarly, a smaller Red-Dead project that only generates hydropower can deliver large flows to the Dead Sea when the sale price of generated electricity is sufficiently high. However, for all restoration options, net benefits fall and water scarcity rises as flows to the Dead Sea increase. This finding suggests (i) each country has no individual incentive to return water to the Dead Sea, and (ii) outside institutions that seek to raise the Dead must also offer countries direct incentives to deliver water to the Sea besides building the countries new infrastructure.

  18. Raising the Dead without a Red Sea-Dead Sea project? Hydro-economics and governance

    NASA Astrophysics Data System (ADS)

    Rosenberg, D. E.

    2011-04-01

    Seven decades of extractions have dramatically reduced Jordan River flows, lowered the Dead Sea level, opened sink holes, and caused other environmental problems. The fix Jordan, Israel, and the Palestinians propose would build an expensive multipurpose conveyance project from the Red Sea to the Dead Sea that would also generate hydropower and desalinate water. This paper compares the Red-Dead project to alternatives that may also raise the Dead Sea level. Hydro-economic model results for the Jordan-Israel-Palestinian inter-tied water systems show two restoration alternatives are more economically viable than the proposed Red-Dead project. Many decentralized new supply, wastewater reuse, conveyance, conservation, and leak reduction projects and programs in each country can together increase economic benefits and reliably deliver up to 900 MCM yr-1 to the Dead Sea. Similarly, a smaller Red-Dead project that only generates hydropower can deliver large flows to the Dead Sea when the sale price of generated electricity is sufficiently high. However, for all restoration options, net benefits fall and water scarcity rises as flows to the Dead Sea increase. This finding suggests (i) each country has no individual incentive to return water to the Dead Sea, and (ii) outside institutions that seek to raise the Dead must also offer countries direct incentives to deliver water to the Sea besides building the countries new infrastructure.

  19. An Observational Study of Sea Breezes Along the Alaskan Beaufort Sea Coast: Part I.

    NASA Astrophysics Data System (ADS)

    Kozo, Thomas L.

    1982-07-01

    Though sea breezes are not often associated with the arctic, atmospheric environmental data collected in August 1976, 1977 and 1979 along the Beaufort Sea Coast of Alaska offer both circumstantial and direct evidence of the existence of sea breezes at 70°N latitude. To estimate total atmospheric boundary layer turning, a two-dimensional least squares technique is used to calculate a three hourly geostrophic wind (above the atmospheric boundary layer) with data from irregularly distributed surface pressure stations for simultaneous comparison to surface wind data. Results indicated the average turning of the wind from above the boundary layer to the surface was 120° on sea breeze days. Rotary spectra from time series data of surface winds measured at offshore and inshore sites have shown the horizontal extent of sea breeze influence to include at least a 20 km zone centered on the coastline. The sea breeze is largely responsible for the increased persistence of surface onshore (northeasterly and easterly) winds documented in August historical data for the Alaskan Beaufort Sea Coast.The data base for arctic sea breeze studies has been enhanced by the discovery and development of the Prudhoe Bay oil fields (mid-sixties). Since the nearshore ocean current flow along the Alaskan Beaufort Sea Coast is primarily wind driven, a direct application to oil spill trajectories in lagoons and embayments exists.

  20. Two wind-driven modes of winter sea ice variability in the Barents Sea

    NASA Astrophysics Data System (ADS)

    Herbaut, Christophe; Houssais, Marie-Noëlle; Close, Sally; Blaizot, Anne-Cécile

    2015-12-01

    The interannual variability of the winter sea ice area in the Barents Sea is investigated using SMMR-SSM/I data and a coupled ocean-sea ice model over the period 1979-2012. Our analysis reveals that the sea ice area in the northern and eastern parts of the Barents Sea do not covary. This contrast in behavior allows us to associate two distinct modes of variability with these two regions, with the variability of the overall Barents Sea ice cover being predominantly captured by the northern mode. Both modes show a dominant, near in-phase response to the surface wind, both being associated with different spatial patterns. The northern mode emerges in response to northwesterly wind anomalies which favor the export of ice and surface polar water from the Arctic between Svalbard and Franz Josef Land. Atlantic Water temperature anomalies, formed concomitantly with northerly wind anomalies in the vicinity of the Barents Sea Opening, also influence the northern mode in the following winter. These temperature anomalies are linked to local convergence of the oceanic heat transport. The delayed influence of the ocean on the sea ice is found primarily in the northeastern Barents Sea and occurs through the re-emergence of the Atlantic water temperature anomalies at the surface in the following fall and winter. An ocean-to-atmosphere feedback initiated by October SST anomalies in the central Barents Sea is further identified. This feedback is hypothesized to enhance the sea ice response in the northern Barents Sea by promoting the formation of meridional wind anomalies. In contrast, the eastern mode of variability of the Barents Sea ice mainly responds to wind anomalies with a strong zonal component, and is less influenced by the Atlantic Water temperature variability than the northern mode. While our results clearly highlight a role of the ocean in the Barents Sea ice variability, this role appears to be more spatially restricted following the sudden northward retreat of the ice margin in 2004. In particular, the sudden drop in the sea ice area in 2004 could not be linked to earlier Atlantic water changes in the Barents Sea Opening.

  1. Sea ice and oceanic processes on the Ross Sea continental shelf

    NASA Technical Reports Server (NTRS)

    Jacobs, S. S.; Comiso, J. C.

    1989-01-01

    The spatial and temporal variability of Antarctic sea ice concentrations on the Ross Sea continental shelf have been investigated in relation to oceanic and atmospheric forcing. Sea ice data were derived from Nimbus 7 scanning multichannel microwave radiometer (SMMR) brightness temperatures from 1979-1986. Ice cover over the shelf was persistently lower than above the adjacent deep ocean, averaging 86 percent during winter with little month-to-month of interannual variability. The large spring Ross Sea polynya on the western shelf results in a longer period of summer insolation, greater surface layer heat storage, and later ice formation in that region the following autumn.

  2. Inter-annual sea level variability in the southern South China Sea

    NASA Astrophysics Data System (ADS)

    Soumya, M.; Vethamony, P.; Tkalich, P.

    2015-10-01

    The South China Sea (SCS) is the largest marginal sea in the western Pacific Basin. Sea level anomalies (SLAs) in the southern South China Sea (SSCS) are assumed to be governed by various phenomena associated with the adjacent parts of the Indian Ocean and the Pacific Ocean. We have used monthly sea level anomalies obtained from 12 tide gauge stations of PSMSL and UHSLC and merged and gridded AVISO products of SLAs (sea level anomalies) derived from satellite altimeter. We find that IOD-influenced inter-annual variations are found only in the southwestern and southeastern coastal regions of SSCS. Our analysis reveals that inter-annual regional sea level drops are associated with positive phase of the IOD, and the rises with negative phase of the IOD. SLA variations at decadal scale in the southeastern and northern Gulf of Thailand correlate with Pacific Decadal Oscillations (PDO). Multiple linear regression analysis of inter-annual SLAs and climate indices shows that IOD induced inter-annual variations dominate in the southwestern SCS and it contributes to about ~ 40% of inter-annual sea level variation. Meanwhile, ENSO contributes to around ~ 30% variation in sea level in the southwestern and ~ 40% variation in the southeastern SSCS. The present study also suggests that inter-annual SLA variations in the SSCS can occur by ENSO and IOD induced changes in wind stress curl and volume transport variations.

  3. Intercomparisons of sea ice concentration from SSM/I and AVHRR data of the Ross Sea

    SciTech Connect

    Zibordi, G.; Woert, M. van; Meloni, G.P.; Canossi, I.

    1995-09-01

    SSM/I and AVHRR sea ice mapping capabilities are analyzed using Antarctic data acquired during November 1990 over the Ross Sea. Quantitative comparisons between sea ice concentrations obtained from SSM/I and AVHRR data show differences of {minus}10% to + 50% with average differences between 9% and 17%. These differences are mainly attributed to: (a) sea ice reflectance and emissivity spatial variations occurring during the melting season, which reduce the accuracy of concentrations obtained with global tie points, and (b) colocation inaccuracy between SSM/I and AVHRR grids.

  4. [Hygiene problems in inland and sea navigation].

    PubMed

    Goethe, H

    1983-09-01

    Both waste and sewage disposal are ubiquitous problems which have also affected navigation. Shipping is a very important transport carrier on a worldwide basis which together with the fishing industry employs roughly two million people. The problems associated with waste and sewage disposal obviously present a severe hazard to the coastal areas, narrow sea basins and, in particular, to inland and open-sea waterways. These problems are particularly alarming in large sea-ports, docks without outfall etc. The reduction of the crews aboard the ships operated by the industialised countries has helped to quantitatively ease the problem of waste and sewage disposal caused by the crews. However, passenger steamers with high waste and sewage volumes cause considerable nuisance in small harbours and the same holds for the disposal of technical waste products from ships such as dunnage packing material, ropes, plastic material, oil, etc. The quantity of waste water aboard a sea-going vessel including that from the toilets, washrooms, galley, and cleaning is rather considerable and is estimated at 300 litres per person and day under tropical climates. The volume of waste varies greatly and depends mainly on the type of material used aboard as mentioned above. Passenger liners with a very high volume of kitchen refuse and other solid waste give rise to specially insidious problems. In the past, sea-going vessels as well as ships employed in inland navigation used to throw overboard any type of refuse and sewage. However, during the last few decades the port authorities and also governments have introduced local and national regulations ruling that waste may no longer be thrown into harbour basins, but must be collected and disposed of on shore. Most ships have complied with these provisions, but some of them kept the collected refuse aboard and disposed of it on the open sea outside the harbours. International agreements on the prohibition of emptying oil and oil-containing waste into the sea were reached as early as 1954. The first rigorous provisions on the strict prohibition of discharging sewage and throwing spoilage overboard on the sea were promulgated around 1960 for the Great Lakes (USA and Canada) as well as for some Baltic Sea and Black Sea harbours (USSR). This legislation has been increasingly tightened. The international agreement on the prevention of sea pollution by ships, submitted by the International Maritime Consultative Organization (IMCO) in 1973 and 1978, strictly bans the throwing overboard or discharging of oil, plastic material, stowing and packing materials etc. as well as unperishable substances.(ABSTRACT TRUNCATED AT 400 WORDS) PMID:6649997

  5. Mirabilite solubility in equilibrium sea ice brines

    NASA Astrophysics Data System (ADS)

    Butler, Benjamin Miles; Papadimitriou, Stathys; Santoro, Anna; Kennedy, Hilary

    2016-06-01

    The sea ice microstructure is permeated by brine channels and pockets that contain concentrated seawater-derived brine. Cooling the sea ice results in further formation of pure ice within these pockets as thermal equilibrium is attained, resulting in a smaller volume of increasingly concentrated residual brine. The coupled changes in temperature and ionic composition result in supersaturation of the brine with respect to mirabilite (Na2SO4·10H2O) at temperatures below -6.38 °C, which consequently precipitates within the sea ice microstructure. Here, mirabilite solubility in natural and synthetic seawater derived brines, representative of sea ice at thermal equilibrium, has been measured in laboratory experiments between 0.2 and -20.6 °C, and hence we present a detailed examination of mirabilite dynamics within the sea ice system. Below -6.38 °C mirabilite displays particularly large changes in solubility as the temperature decreases, and by -20.6 °C its precipitation results in 12.90% and 91.97% reductions in the total dissolved Na+ and SO42- concentrations respectively, compared to that of conservative seawater concentration. Such large non-conservative changes in brine composition could potentially impact upon the measurement of sea ice brine salinity and pH, whilst the altered osmotic conditions may create additional challenges for the sympagic organisms that inhabit the sea ice system. At temperatures above -6.38 °C, mirabilite again displays large changes in solubility that likely aid in impeding its identification in field samples of sea ice. Our solubility measurements display excellent agreement with that of the FREZCHEM model, which was therefore used to supplement our measurements to colder temperatures. Measured and modelled solubility data were incorporated into a 1D model for the growth of first-year Arctic sea ice. Model results ultimately suggest that mirabilite has a near ubiquitous presence in much of the sea ice on Earth, and illustrate the spatial and temporal evolution of mirabilite within sea ice as it grows throughout an Arctic winter, reaching maximum concentrations of 2.3 g kg-1.

  6. Metagenomic studies of the Red Sea.

    PubMed

    Behzad, Hayedeh; Ibarra, Martin Augusto; Mineta, Katsuhiko; Gojobori, Takashi

    2016-02-01

    Metagenomics has significantly advanced the field of marine microbial ecology, revealing the vast diversity of previously unknown microbial life forms in different marine niches. The tremendous amount of data generated has enabled identification of a large number of microbial genes (metagenomes), their community interactions, adaptation mechanisms, and their potential applications in pharmaceutical and biotechnology-based industries. Comparative metagenomics reveals that microbial diversity is a function of the local environment, meaning that unique or unusual environments typically harbor novel microbial species with unique genes and metabolic pathways. The Red Sea has an abundance of unique characteristics; however, its microbiota is one of the least studied among marine environments. The Red Sea harbors approximately 25 hot anoxic brine pools, plus a vibrant coral reef ecosystem. Physiochemical studies describe the Red Sea as an oligotrophic environment that contains one of the warmest and saltiest waters in the world with year-round high UV radiations. These characteristics are believed to have shaped the evolution of microbial communities in the Red Sea. Over-representation of genes involved in DNA repair, high-intensity light responses, and osmoregulation were found in the Red Sea metagenomic databases suggesting acquisition of specific environmental adaptation by the Red Sea microbiota. The Red Sea brine pools harbor a diverse range of halophilic and thermophilic bacterial and archaeal communities, which are potential sources of enzymes for pharmaceutical and biotechnology-based application. Understanding the mechanisms of these adaptations and their function within the larger ecosystem could also prove useful in light of predicted global warming scenarios where global ocean temperatures are expected to rise by 1-3°C in the next few decades. In this review, we provide an overview of the published metagenomic studies that were conducted in the Red Sea, and the bio-prospecting potential of the Red Sea microbiota. Furthermore, we discuss the limitations of the previous studies and the need for generating a large and representative metagenomic database of the Red Sea to help establish a dynamic model of the Red Sea microbiota. PMID:26526132

  7. Satellite Remote Sensing: Passive-Microwave Measurements of Sea Ice

    NASA Technical Reports Server (NTRS)

    Parkinson, Claire L.; Zukor, Dorothy J. (Technical Monitor)

    2001-01-01

    Satellite passive-microwave measurements of sea ice have provided global or near-global sea ice data for most of the period since the launch of the Nimbus 5 satellite in December 1972, and have done so with horizontal resolutions on the order of 25-50 km and a frequency of every few days. These data have been used to calculate sea ice concentrations (percent areal coverages), sea ice extents, the length of the sea ice season, sea ice temperatures, and sea ice velocities, and to determine the timing of the seasonal onset of melt as well as aspects of the ice-type composition of the sea ice cover. In each case, the calculations are based on the microwave emission characteristics of sea ice and the important contrasts between the microwave emissions of sea ice and those of the surrounding liquid-water medium.

  8. Deep sea tides determination from GEOS-3

    NASA Technical Reports Server (NTRS)

    Maul, G. A.; Yanaway, A.

    1978-01-01

    GEOS 3 altimeter data in a 5 degree X 5 degree square centered at 30 deg N, 70 deg W were analyzed to evaluate deep sea tide determination from a spacecraft. The signal to noise ratio of known tidal variability to altimeter measurement of sea level above the ellipsoid was 0.1. A sample was obtained in a 5 deg x 5 deg area approximately once every four days. The randomly spaced time series was analyzed using two independent least squares techniques.

  9. Dust Storm, Red Sea and Saudi Arabia

    NASA Technical Reports Server (NTRS)

    1992-01-01

    Outlined against the dark blue water of the Red Sea, a prominent dust storm is making its way across the Red Sea into Saudi Arabia (22.0N, 39.0E) between the Islamic holy cities of Medinah and Mecca. Funneled through a gap in the coastal ranges of southern Sudan near the Ethiopian border, dust storms frequently will blow counter to the prevailing tropical easterly winds of the region.

  10. Advances in search and rescue at sea

    NASA Astrophysics Data System (ADS)

    Breivik, Øyvind; Allen, Arthur Addoms; Maisondieu, Christophe; Olagnon, Michel

    2013-01-01

    A topical collection on "Advances in Search and Rescue at Sea" has appeared in recent issues of Ocean Dynamics following the latest in a series of workshops on "Technologies for Search and Rescue and other Emergency Marine Operations" (2004, 2006, 2008, and 2011), hosted by IFREMER in Brest, France. Here, we give a brief overview of the history of search and rescue at sea before we summarize the main results of the papers that have appeared in the topical collection.

  11. Future high sea levels in south Sweden

    SciTech Connect

    Blomgren, S.H.; Hanson, H.

    1997-12-31

    An estimation of future mean high water levels in Oeresund and the southwest Baltic Sea is presented together with a discussion of probable consequences for Falsterbo Peninsula, a trumpet-shaped sandy formation of some 25 km{sup 2} size situated in the very southwest corner of Sweden. A literature review coupled with sea-level measurements and observations made in the area every four hours since October 1945 are given and comprise the base for the present analysis.

  12. The Red Sea Modeling and Forecasting System

    NASA Astrophysics Data System (ADS)

    Hoteit, Ibrahim; Gopalakrishnan, Ganesh; Latif, Hatem; Toye, Habib; Zhan, Peng; Kartadikaria, Aditya R.; Viswanadhapalli, Yesubabu; Yao, Fengchao; Triantafyllou, George; Langodan, Sabique; Cavaleri, Luigi; Guo, Daquan; Johns, Burt

    2015-04-01

    Despite its importance for a variety of socio-economical and political reasons and the presence of extensive coral reef gardens along its shores, the Red Sea remains one of the most under-studied large marine physical and biological systems in the global ocean. This contribution will present our efforts to build advanced modeling and forecasting capabilities for the Red Sea, which is part of the newly established Saudi ARAMCO Marine Environmental Research Center at KAUST (SAMERCK). Our Red Sea modeling system compromises both regional and nested costal MIT general circulation models (MITgcm) with resolutions varying between 8 km and 250 m to simulate the general circulation and mesoscale dynamics at various spatial scales, a 10-km resolution Weather Research Forecasting (WRF) model to simulate the atmospheric conditions, a 4-km resolution European Regional Seas Ecosystem Model (ERSEM) to simulate the Red Sea ecosystem, and a 1-km resolution WAVEWATCH-III model to simulate the wind driven surface waves conditions. We have also implemented an oil spill model, and a probabilistic dispersion and larval connectivity modeling system (CMS) based on a stochastic Lagrangian framework and incorporating biological attributes. We are using the models outputs together with available observational data to study all aspects of the Red Sea circulations. Advanced monitoring capabilities are being deployed in the Red Sea as part of the SAMERCK, comprising multiple gliders equipped with hydrographical and biological sensors, high frequency (HF) surface current/wave mapping, buoys/ moorings, etc, complementing the available satellite ocean and atmospheric observations and Automatic Weather Stations (AWS). The Red Sea models have also been equipped with advanced data assimilation capabilities. Fully parallel ensemble-based Kalman filtering (EnKF) algorithms have been implemented with the MITgcm and ERSEM for assimilating all available multivariate satellite and in-situ data sets. We have also developed advanced visualization tools to interactively analyze the forecasts and their ensemble-based uncertainties.

  13. 33 CFR 2.32 - High seas.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false High seas. 2.32 Section 2.32 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY GENERAL JURISDICTION Jurisdictional Terms § 2.32 High seas. (a) For purposes of special maritime and territorial jurisdiction of the United States as defined in 18 U.S.C....

  14. 33 CFR 2.32 - High seas.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... chapter and 46 CFR part 7. (c) For the purposes of 14 U.S.C. 89(a), 14 U.S.C. 86, 33 U.S.C. 409, and 33 U... nations. (d) Under customary international law as reflected in the 1982 United Nations Convention on the Law of the Sea and without prejudice to high seas freedoms that may be exercised within...

  15. 33 CFR 2.32 - High seas.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... chapter and 46 CFR part 7. (c) For the purposes of 14 U.S.C. 89(a), 14 U.S.C. 86, 33 U.S.C. 409, and 33 U... nations. (d) Under customary international law as reflected in the 1982 United Nations Convention on the Law of the Sea and without prejudice to high seas freedoms that may be exercised within...

  16. 33 CFR 2.32 - High seas.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... chapter and 46 CFR part 7. (c) For the purposes of 14 U.S.C. 89(a), 14 U.S.C. 86, 33 U.S.C. 409, and 33 U... nations. (d) Under customary international law as reflected in the 1982 United Nations Convention on the Law of the Sea and without prejudice to high seas freedoms that may be exercised within...

  17. 33 CFR 2.32 - High seas.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... chapter and 46 CFR part 7. (c) For the purposes of 14 U.S.C. 89(a), 14 U.S.C. 86, 33 U.S.C. 409, and 33 U... nations. (d) Under customary international law as reflected in the 1982 United Nations Convention on the Law of the Sea and without prejudice to high seas freedoms that may be exercised within...

  18. Sea surface temperature variability in the Colombian Basin, Caribbean Sea

    NASA Astrophysics Data System (ADS)

    Ruiz-Ochoa, Mauricio; Beier, Emilio; Bernal, Gladys; Barton, Eric Desmond

    2012-06-01

    Daily sea surface temperature (SST) data from the Advanced Very High Resolution Radiometer (AVHRR) database with ∼4 km of spatial resolution were analyzed for the period 1985-2009 in the Colombian Basin using harmonic and empirical orthogonal function (EOF) analysis. The data were compared with observational records in the Rosario Island National Park at 10 m depth (T10) from March 2003 to August 2005. SST values were higher than T10 from June to October (rainy season), but similar from December to February (dry season); both data sets have similar coefficient of variation. The mean SST distribution varies spatially, with minimum SST values in the coastal zone of La Guajira Peninsula and maximum values in the Darien and Mosquitos Gulfs. The seasonal variability explains up to 75% of the total variability in La Guajira, a high value compared with 40% in the Mosquitos Gulf. The most important feature of the splitting of SST variation into annual and semiannual harmonics in La Guajira is the relationship between their amplitudes. These are of the same order, which is not common in other ocean zones, where the semiannual component is only a small fraction of the annual dominated by the solar warming. The river water discharge, highest from August to November, produces low density surface water, reduces vertical mixing and limits the absorption of solar radiation to a thin surface layer, explaining the discrepancy between SST and T10 in the rainy season. The decomposition of the SST in EOFs indicated that the dominant mode of the basin is a uniform interannual variation in phase with the North Tropical Atlantic Index. The second mode, representing the variability of the Guajira upwelling, covaried strongly with the second mode of wind stress curl. The third mode reflected the role of the vertical atmospheric circulation cell associated with the Caribbean Low Level Jet off Central America.

  19. 50 CFR Appendix F to Part 622 - Specifications for Sea Turtle Mitigation Gear and Sea Turtle Handling and Release Requirements

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 50 Wildlife and Fisheries 12 2014-10-01 2014-10-01 false Specifications for Sea Turtle Mitigation Gear and Sea Turtle Handling and Release Requirements F Appendix F to Part 622 Wildlife and Fisheries... 622—Specifications for Sea Turtle Mitigation Gear and Sea Turtle Handling and Release Requirements...

  20. Investigation of radar discrimination of sea ice

    NASA Technical Reports Server (NTRS)

    Parashar, S. K.; Biggs, A. W.; Fung, A. K.; Moore, R. K.

    1974-01-01

    The ability of radar to discriminate sea ice types and their thickness was studied. Radar backscatter measurements at 400 MHz (multi-polarization) and 13.3 GHz (VV polarization) obtained from NASA Earth Resources Aircraft Program Mission 126 were analyzed in detail. The scatterometer data were separated into seven categories of sea ice according to age and thickness as interpreted from stereo aerial photographs. The variations of radar backscatter cross-section with sea ice thickness at various angles are presented at the two frequencies. There is a reversal of angular character of radar return from sea ice less than 18 cm thick at the two frequencies. Multi-year ice (sea ice greater than 180 cm thick) gives strongest return at 13.3 GHz. First-year ice (30 cm to 90 cm thick) gives strongest return at 400 MHz. Open water can be differentiated at both the frequencies. Four-polarization 16.5 GHz radar imagery was also obtained. Open water and three categories of sea ice can be identified on the images. The results of the imagery analysis are consistent with the radar scatterometer results.

  1. Temperature impacts on deep-sea biodiversity.

    PubMed

    Yasuhara, Moriaki; Danovaro, Roberto

    2016-05-01

    Temperature is considered to be a fundamental factor controlling biodiversity in marine ecosystems, but precisely what role temperature plays in modulating diversity is still not clear. The deep ocean, lacking light and in situ photosynthetic primary production, is an ideal model system to test the effects of temperature changes on biodiversity. Here we synthesize current knowledge on temperature-diversity relationships in the deep sea. Our results from both present and past deep-sea assemblages suggest that, when a wide range of deep-sea bottom-water temperatures is considered, a unimodal relationship exists between temperature and diversity (that may be right skewed). It is possible that temperature is important only when at relatively high and low levels but does not play a major role in the intermediate temperature range. Possible mechanisms explaining the temperature-biodiversity relationship include the physiological-tolerance hypothesis, the metabolic hypothesis, island biogeography theory, or some combination of these. The possible unimodal relationship discussed here may allow us to identify tipping points at which on-going global change and deep-water warming may increase or decrease deep-sea biodiversity. Predicted changes in deep-sea temperatures due to human-induced climate change may have more adverse consequences than expected considering the sensitivity of deep-sea ecosystems to temperature changes. PMID:25523624

  2. Development and application of Labrador Sea climatologies

    NASA Astrophysics Data System (ADS)

    Cetin, Nilgun

    2007-05-01

    Two yearly climatologies of the Labrador Sea are developed. One is based on the traditional geopotential coordinates, and the other employs isopycnal coordinates in the vertical. The analysis of the results show that the isopycnal climatology has more skill at describing the mean state of the Labrador Sea, without smoothing out important flow features such as strong boundary currents and fronts. Seasonal climatologies based on the isopycnal coordinates in the vertical are also developed to study seasonal variability of the Labrador Sea hydrography and freshwater and heat fluxes. The greatest seasonal variability is observed in winter, the season in which deep convective overturning takes place. By using the objective analysis technique which successfully represented the dynamics of the Labrador Sea, a pseudo time-series of water properties is developed to study their inter-annual variability. The contribution of the West Greenland Current to the interior Labrador Sea freshwater budget is found to be greater than that of the Labrador Current, even though the Labrador Current has a larger freshwater content. Diagnostic calculations show that the Labrador Current flows southward mostly parallel to the isobaths without much of its fresher waters ever crossing into the interior Labrador Sea.

  3. A Late Pleistocene sea level stack

    NASA Astrophysics Data System (ADS)

    Spratt, R. M.; Lisiecki, L. E.

    2015-08-01

    Late Pleistocene sea level has been reconstructed from ocean sediment core data using a wide variety of proxies and models. However, the accuracy of individual reconstructions is limited by measurement error, local variations in salinity and temperature, and assumptions particular to each technique. Here we present a sea level stack (average) which increases the signal-to-noise ratio of individual reconstructions. Specifically, we perform principal component analysis (PCA) on seven records from 0-430 ka and five records from 0-798 ka. The first principal component, which we use as the stack, describes ~80 % of the variance in the data and is similar using either five or seven records. After scaling the stack based on Holocene and Last Glacial Maximum (LGM) sea level estimates, the stack agrees to within 5 m with isostatically adjusted coral sea level estimates for Marine Isotope Stages 5e and 11 (125 and 400 ka, respectively). When we compare the sea level stack with the δ18O of benthic foraminifera, we find that sea level change accounts for about ~40 % of the total orbital-band variance in benthic δ18O, compared to a 65 % contribution during the LGM-to-Holocene transition. Additionally, the second and third principal components of our analyses reflect differences between proxy records associated with spatial variations in the δ18O of seawater.

  4. Lessons from sea louse and salmon epidemiology.

    PubMed

    Groner, Maya L; Rogers, Luke A; Bateman, Andrew W; Connors, Brendan M; Frazer, L Neil; Godwin, Sean C; Krkošek, Martin; Lewis, Mark A; Peacock, Stephanie J; Rees, Erin E; Revie, Crawford W; Schlägel, Ulrike E

    2016-03-01

    Effective disease management can benefit from mathematical models that identify drivers of epidemiological change and guide decision-making. This is well illustrated in the host-parasite system of sea lice and salmon, which has been modelled extensively due to the economic costs associated with sea louse infections on salmon farms and the conservation concerns associated with sea louse infections on wild salmon. Consequently, a rich modelling literature devoted to sea louse and salmon epidemiology has been developed. We provide a synthesis of the mathematical and statistical models that have been used to study the epidemiology of sea lice and salmon. These studies span both conceptual and tactical models to quantify the effects of infections on host populations and communities, describe and predict patterns of transmission and dispersal, and guide evidence-based management of wild and farmed salmon. As aquaculture production continues to increase, advances made in modelling sea louse and salmon epidemiology should inform the sustainable management of marine resources. PMID:26880836

  5. The Last Arctic Sea Ice Refuge

    NASA Astrophysics Data System (ADS)

    Pfirman, S. L.; Tremblay, B.; Newton, R.; Fowler, C.

    2010-12-01

    Summer sea ice may persist along the northern flank of Canada and Greenland for decades longer than the rest of the Arctic, raising the possibility of a naturally formed refugium for ice-associated species. Observations and models indicate that some ice in this region forms locally, while some is transported to the area by winds and ocean currents. Depending on future changes in melt patterns and sea ice transport rates, both the central Arctic and Siberian shelf seas may be sources of ice to the region. An international system of monitoring and management of the sea ice refuge, along with the ice source regions, has the potential to maintain viable habitat for ice-associated species, including polar bears, for decades into the future. Issues to consider in developing a strategy include: + the likely duration and extent of summer sea ice in this region based on observations, models and paleoenvironmental information + the extent and characteristics of the “ice shed” contributing sea ice to the refuge, including its dynamics, physical and biological characteristics as well as potential for contamination from local or long-range sources + likely assemblages of ice-associated species and their habitats + potential stressors such as transportation, tourism, resource extraction, contamination + policy, governance, and development issues including management strategies that could maintain the viability of the refuge.

  6. The anisotropic scattering coefficient of sea ice

    NASA Astrophysics Data System (ADS)

    Katlein, Christian; Nicolaus, Marcel; Petrich, Chris

    2014-02-01

    Radiative transfer in sea ice is subject to anisotropic, multiple scattering. The impact of anisotropy on the light field under sea ice was found to be substantial and has been quantified. In this study, a large data set of irradiance and radiance measurements under sea ice has been acquired with a Remotely Operated Vehicle (ROV) in the central Arctic. Measurements are interpreted in the context of numerical radiative transfer calculations, laboratory experiments, and microstructure analysis. The ratio of synchronous measurements of transmitted irradiance to radiance shows a clear deviation from an isotropic under-ice light field. We find that the angular radiance distribution under sea ice is more downward directed than expected for an isotropic light field. This effect can be attributed to the anisotropic scattering coefficient within sea ice. Assuming an isotropic radiance distribution under sea ice leads to significant errors in light-field modeling and the interpretation of radiation measurements. Quantification of the light field geometry is crucial for correct conversion of radiance data acquired by Autonomous Underwater Vehicles (AUVs) and ROVs.

  7. Abundance of sea kraits correlates with precipitation.

    PubMed

    Lillywhite, Harvey B; Tu, Ming-Chung

    2011-01-01

    Recent studies have shown that sea kraits (Laticauda spp.)--amphibious sea snakes--dehydrate without a source of fresh water, drink only fresh water or very dilute brackish water, and have a spatial distribution of abundance that correlates with freshwater sites in Taiwan. The spatial distribution correlates with sites where there is a source of fresh water in addition to local precipitation. Here we report six years of longitudinal data on the abundance of sea kraits related to precipitation at sites where these snakes are normally abundant in the coastal waters of Lanyu (Orchid Island), Taiwan. The number of observed sea kraits varies from year-to-year and correlates positively with previous 6-mo cumulative rainfall, which serves as an inverse index of drought. Grouped data for snake counts indicate that mean abundance in wet years is nearly 3-fold greater than in dry years, and this difference is significant. These data corroborate previous findings and suggest that freshwater dependence influences the abundance or activity of sea kraits on both spatial and temporal scales. The increasing evidence for freshwater dependence in these and other marine species have important implications for the possible impact of climate change on sea snake distributions. PMID:22194849

  8. The Pechora Sea: Past, recent, and future

    NASA Astrophysics Data System (ADS)

    Pavlidis, Yu. A.; Nikiforov, S. L.; Ogorodov, S. A.; Tarasov, G. A.

    2007-12-01

    The main stages in the development of the Pechora Sea are discussed. It is established that, during the high sea level stand corresponding to the warmest epoch of the Mikulino Interglacial, the Pechora Sea represented a more spacious, as compared with its present-day size, basin owing to the flooded valleys of river lower reaches. No sea in its present-day configuration existed during the last (Valdai) glaciation. At that time, the sea could have occupied only a narrow area along the southern coast of Novaya Zemlya, where marine sedimentation was in progress during the Late Pleistocene and Holocene. During the glaciation and postglacial time, the dried bottom of the former Pechora Sea accumulated large volumes of sand that are now concentrated largely in the accretion structures along its southern coast. In the current century, changes will occur mainly in the coastal zone of the Russkii Zavorot Peninsula, Pesyakov Island, the Varandei Settlement area, and the Medynskii Zavorot Peninsula, where a shoreline retreat for a distance of 0.5 km is expected.

  9. Operational use of high-resolution sst in a coupled sea ice-ocean model

    NASA Astrophysics Data System (ADS)

    Albretsen, A.

    2003-04-01

    A high-latitude, near real time, sea surface temperature (SST) product with 10 km resolution is developed at the Norwegian Meteorological Institute (met.no) through the EUMETSAT project OSI-SAF (Ocean and Sea Ice Satellite Application Facility). The product covers the Atlantic Ocean from 50N to 90N and is produced twice daily. A digitized SST and sea ice map is produced manually once a week at the Ice Mapping Service at met.no using all available information from the previous week. This map is the basis for a daily SST analysis, in which the most recent OSI-SAF SST products are successively overlaid. The resulting SST analysis field is then used in a simple data assimilation scheme in a coupled ice-ocean model to perform daily 10 days forecasts of ocean and sea ice variables. Also, the associated OSI-SAF sea ice concentration product, built from different polar orbiting satellites, is assimilated into the sea ice model. Preliminary estimates of impact on forecast skill and error statistics will be presented.

  10. Marine mammals' influence on ecosystem processes affecting fisheries in the Barents Sea is trivial.

    PubMed

    Corkeron, Peter J

    2009-04-23

    Some interpretations of ecosystem-based fishery management include culling marine mammals as an integral component. The current Norwegian policy on marine mammal management is one example. Scientific support for this policy includes the Scenario Barents Sea (SBS) models. These modelled interactions between cod, Gadus morhua, herring, Clupea harengus, capelin, Mallotus villosus and northern minke whales, Balaenoptera acutorostrata. Adding harp seals Phoca groenlandica into this top-down modelling approach resulted in unrealistic model outputs. Another set of models of the Barents Sea fish-fisheries system focused on interactions within and between the three fish populations, fisheries and climate. These model key processes of the system successfully. Continuing calls to support the SBS models despite their failure suggest a belief that marine mammal predation must be a problem for fisheries. The best available scientific evidence provides no justification for marine mammal culls as a primary component of an ecosystem-based approach to managing the fisheries of the Barents Sea. PMID:19126534

  11. Deep-sea ostracode shell chemistry (Mg:Ca ratios) and late Quaternary Arctic Ocean history

    USGS Publications Warehouse

    Cronin, T. M.; Dwyer, G.S.; Baker, P.A.; Rodriguez-Lazaro, J.; Briggs, W.M., Jr.

    1996-01-01

    The magnesium:calcium (Mg:Ca) and strontium:calcium (Sr:Ca) ratios were investigated in shells of the benthic ostracode genus Krithe obtained from 64 core-tops from water depths of 73 to 4411 m in the Arctic Ocean and Nordic seas to determine the potential of ostracode shell chemistry for paleoceanographic study. Shells from the abyssal plain and ridges of the Nansen, Amundsen and Makarov basins and the Norwegian and Greenland seas had a wide scatter of Mg:Ca ratios ranging from 0.007 to 0.012 that may signify post-mortem chemical alteration of the shells from Arctic deep-sea environments below about 1000 m water depth. There is a positive correlation (r2=0.59) between Mg:Ca ratios and bottom-water temperature in Krithe shells from water depths <900 m.

  12. Towards uncertainty estimation for operational forecast products - a multi-model-ensemble approach for the North Sea and the Baltic Sea

    NASA Astrophysics Data System (ADS)

    Golbeck, Inga; Li, Xin; Janssen, Frank

    2014-05-01

    Several independent operational ocean models provide forecasts of the ocean state (e.g. sea level, temperature, salinity and ice cover) in the North Sea and the Baltic Sea on a daily basis. These forecasts are the primary source of information for a variety of information and emergency response systems used e.g. to issue sea level warnings or carry out oil drift forecast. The forecasts are of course highly valuable as such, but often suffer from a lack of information on their uncertainty. With the aim of augmenting the existing operational ocean forecasts in the North Sea and the Baltic Sea by a measure of uncertainty a multi-model-ensemble (MME) system for sea surface temperature (SST), sea surface salinity (SSS) and water transports has been set up in the framework of the MyOcean-2 project. Members of MyOcean-2, the NOOS² and HIROMB/BOOS³ communities provide 48h-forecasts serving as inputs. Different variables are processed separately due to their different physical characteristics. Based on the so far collected daily MME products of SST and SSS, a statistical method, Empirical Orthogonal Function (EOF) analysis is applied to assess their spatial and temporal variability. For sea surface currents, progressive vector diagrams at specific points are consulted to estimate the performance of the circulation models especially in hydrodynamic important areas, e.g. inflow/outflow of the Baltic Sea, Norwegian trench and English Channel. For further versions of the MME system, it is planned to extend the MME to other variables like e.g. sea level, ocean currents or ice cover based on the needs of the model providers and their customers. It is also planned to include in-situ data to augment the uncertainty information and for validation purposes. Additionally, weighting methods will be implemented into the MME system to develop more complex uncertainty measures. The methodology used to create the MME will be outlined and different ensemble products will be presented. In addition, some preliminary results based on the statistical analysis of the uncertainty measures provide first estimates of the regional and temporal performance of the ocean models for each parameter. ²Northwest European Shelf Operational Oceanography System ³High-resolution Operational Model of the Baltic / Baltic Operational Oceanographic System

  13. Past Sea Level Reconstruction and Variability of Sea Level Trend Patterns over 1958-2005 in the Mediterranean Sea basin

    NASA Astrophysics Data System (ADS)

    Meyssignac, B.; Cazenave, A. A.; Morrow, R. A.; Llovel, W.; Maisongrande, P.; Fenoglio-Marc, L.

    2009-12-01

    For the past decades, there are no direct basin-scale observations informing on the spatial trend patterns in Mediterranean sea level. Yet it is important to know the dominant modes of regional variability on interannual/decadal/multidecadal time scale in the Mediterranean basin and their driving mechanisms. For that purpose, we have developed a reconstruction method of past Mediterranean sea level (since 1958) that combines long tide gauge records of limited coverage and 2-D sea level patterns based on runs from two different Ocean General Circulation Models (OGCMs). Instead of using 2-D spatial patterns from satellite altimetry (as done in previous studies; e.g., Calafat et al., 2009), here we prefer to use OGCM runs on the past few decades on the assumption that they better capture the decadal variability of the spatial trend patterns. The two OGCMs considered are the ORCA05 run (without data assimilation) over 1958-2005 available from the DRAKKAR project and the SODA reanalyse over 1958-2005 available from GODAE (Carton et al., 2008), assimilating all available in situ temperature, salinity and sea level data. The two sea level reconstructions are compared to each other as well as with previous studies (e.g., Calafat et al., 2009). The dominant modes of temporal variability are discussed and sea level hindcasts at tide gauge sites not used in the analysis are compared to actual observations. Comparisons with steric sea level patterns based on in situ hydrographic data are also presented and discussed with regard to the conclusions of past studies based on tide gauge records analysis.

  14. Nordic Seas Precipitation Ground Validation Project

    NASA Astrophysics Data System (ADS)

    Klepp, Christian; Bumke, Karl; Bakan, Stephan; Andersson, Axel

    2010-05-01

    A thorough knowledge of global ocean precipitation is an indispensable prerequisite for the understanding of the water cycle in the global climate system. However, reliable detection of precipitation over the global oceans, especially of solid precipitation, remains a challenging task. This is true for both, passive microwave remote sensing and reanalysis based model estimates. The satellite based HOAPS (Hamburg Ocean Atmosphere Parameters and Fluxes from Satellite Data) climatology contains fields of precipitation, evaporation and the resulting freshwater flux along with 12 additional atmospheric parameters over the global ice-free ocean between 1987 and 2005. Except for the NOAA Pathfinder SST, all basic state variables are calculated from SSM/I passive microwave radiometer measurements. HOAPS contains three main data subsets that originate from one common pixel-level data source. Gridded 0.5 degree monthly, pentad and twice daily data products are freely available from www.hoaps.org. The optical disdrometer ODM 470 is a ground validation instrument capable of measuring rain and snowfall on ships even under high wind speeds. It was used for the first time over the Nordic Seas during the LOFZY 2005 campaign. A dichotomous verification for these snowfall events resulted in a perfect score between the disdrometer, a precipitation detector and a shipboard observer's log. The disdrometer data is further point-to-area collocated against precipitation from three satellite derived climatologies, HOAPS-3, the Global Precipitation Climatology Project (GPCP) one degree daily (1DD) data set, and the Goddard Profiling algorithm, version 2004 (GPROF 2004). Only the HOAPS precipitation turns out to be overall consistent with the disdrometer data resulting in an accuracy of 0.96. The collocated data comprises light precipitation events below 1 mm/h. Therefore two LOFZY case studies with high precipitation rates are presented that still indicate plausible results. Overall, this encourages long-term measurements of ship-to-satellite collocated precipitation in the near future. These measurement campaigns are embedded in a project within the KlimaCampus at the University of Hamburg "Integrated Climate System Analysis and Prediction" (Clisap) and utilize Norwegian Coast Guard ships as instrument carriers.

  15. Sea ice and the ocean mixed layer over the Antarctic shelf seas

    NASA Astrophysics Data System (ADS)

    Petty, A. A.; Holland, P. R.; Feltham, D. L.

    2014-04-01

    An ocean mixed-layer model has been incorporated into the Los Alamos sea ice model CICE to investigate regional variations in the surface-driven formation of Antarctic shelf waters. This model captures well the expected sea ice thickness distribution, and produces deep (> 500 m) mixed layers in the Weddell and Ross shelf seas each winter. This results in the complete destratification of the water column in deep southern coastal regions leading to high-salinity shelf water (HSSW) formation, and also in some shallower regions (no HSSW formation) of these seas. Shallower mixed layers are produced in the Amundsen and Bellingshausen seas. By deconstructing the surface processes driving the mixed-layer depth evolution, we show that the net salt flux from sea ice growth/melt dominates the evolution of the mixed layer in all regions, with a smaller contribution from the surface heat flux and a negligible input from wind stress. The Weddell and Ross shelf seas receive an annual surplus of mixing energy at the surface; the Amundsen shelf sea energy input in autumn/winter is balanced by energy extraction in spring/summer; and the Bellingshausen shelf sea experiences an annual surface energy deficit, through both a low energy input in autumn/winter and the highest energy loss in spring/summer. An analysis of the sea ice mass balance demonstrates the contrasting mean ice growth, melt and export in each region. The Weddell and Ross shelf seas have the highest annual ice growth, with a large fraction exported northwards each year, whereas the Bellingshausen shelf sea experiences the highest annual ice melt, driven by the advection of ice from the northeast. A linear regression analysis is performed to determine the link between the autumn/winter mixed-layer deepening and several atmospheric variables. The Weddell and Ross shelf seas show stronger spatial correlations (temporal mean - intra-regional variability) between the autumn/winter mixed-layer deepening and several atmospheric variables compared to the Amundsen and Bellingshausen. In contrast, the Amundsen and Bellingshausen shelf seas show stronger temporal correlations (shelf sea mean - interannual variability) between the autumn/winter mixed-layer deepening and several atmospheric variables.

  16. Sea ice and the ocean mixed layer over the Antarctic shelf seas

    NASA Astrophysics Data System (ADS)

    Petty, A. A.; Holland, P. R.; Feltham, D. L.

    2013-08-01

    An ocean mixed layer model has been incorporated into the Los Alamos sea ice model CICE to investigate regional variations in the surface-driven formation of Antarctic shelf waters. This model captures well the expected sea ice thickness distribution, and produces deep (> 500 m) mixed layers in the Weddell and Ross shelf seas each winter. This results in the complete destratification of the water column in deep southern coastal regions (leading to HSSW formation) and also in some shallower regions (no HSSW formation) of these seas. Shallower mixed layers are produced in the Amundsen and Bellingshausen seas. By deconstructing the surface power input to the mixed layer, we show that the freshwater flux from sea ice growth/melt dominates the evolution of the mixed layer in all seas, with a smaller contribution from the surface heat flux. The Weddell and Ross shelf seas receive an annual surplus of energy at the surface, the Amundsen shelf sea energy input in autumn/winter is balanced by energy extraction in spring/summer, and the Bellingshausen shelf sea experiences an annual surface energy deficit, through both a low energy input in autumn/winter and the highest energy loss in spring/summer. An analysis of the sea ice mass balance demonstrates the contrasting mean ice growth, melt and export in each region. The Weddell and Ross shelf seas have the highest annual ice growth, with a large fraction exported northwards each year, whereas the Bellingshausen shelf sea experiences the highest annual ice melt, driven by the advection of ice from the northeast. A linear regression analysis is performed to determine the temporal and spatial correlations between the autumn/winter mixed layer power input and several atmospheric variables. The temporal mean Weddell and Ross autumn/winter power input shows stronger spatial correlation to several atmospheric variables compared to the Amundsen and Bellingshausen. In contrast the spatial mean autumn/winter power input shows stronger temporal correlation to several atmospheric variables, in the Amundsen and Bellingshausen. All regions show strong temporal correlation between the autumn/winter surface power input and the meridional wind speed except the Ross, which instead shows moderate correlation to the zonal wind speed. Further regressions demonstrate that this is probably due to the Ross shelf-sea geometry and impact of the ocean turning angle on ice motion, with a more zonal (eastward) wind preventing ice build up along the Cape Adare coast in the eastern Ross shelf sea, increasing ice export.

  17. The Irish Sea: Nutrient status and phytoplankton

    NASA Astrophysics Data System (ADS)

    Gowen, R. J.; Stewart, B. M.

    2005-07-01

    Historical nutrient and phytoplankton data from the Irish Sea are reviewed in the light of recent studies. Mean late winter concentrations of dissolved inorganic nitrogen (DIN as NO 3- + NO 2-), dissolved inorganic phosphate (DIP as PO 43 - ) and silica (Si as SiO 2) in offshore near-surface waters are 8.3, 0.7 and 6.6 μM, respectively. Concentrations in inshore waters of the eastern Irish Sea can reach 57 μM DIN, 5 μM DIP and 17 μM Si. The northwards residual flow through the Irish Sea (≈ 5 km - 3 d - 1 ) is estimated to deliver ≈ 82 × 10 3 t DIN and 12 × 10 3 t DIP during the winter period. The annual freshwater inputs of DIN (including ammonium) and DIP are 123 and 9 × 10 3 t, respectively. Offshore waters of the western Irish Sea are enriched with DIN and DIP (≈ 3.0 and 0.4 μM, respectively) relative to Celtic Sea shelf break concentrations but salinity DIN relationships show that measured winter concentrations are lower than predicted. Denitrification is considered a key process limiting nitrogen enrichment of the Irish Sea. The onset and duration of the production season is controlled by the sub-surface light climate. Differences in depth and tidal mixing in the Irish Sea give rise to regional variation in the timing and length of the production season. Maximum spring bloom biomass in coastal and offshore waters of the western Irish Sea (23 and 16 mg chlorophyll m - 3 , respectively) compares with values of up to 44 mg chlorophyll m - 3 in Liverpool Bay and elevated production and biomass in the latter is attributed to enrichment. There is no evidence that enrichment and changes in nutrient ratios have caused major shifts in phytoplankton composition in Liverpool Bay. Species of Phaeocystis are found throughout the region in most years and together with other microflagellates can dominate the spring bloom. Red tides of dinoflagellates are rare events in the Irish Sea but regular monitoring of phytoplankton in the vicinity of shellfish beds has revealed the presence of toxin-producing dinoflagellates in the Irish Sea.

  18. Solution notches, earthquakes, and sea level, Haiti

    NASA Astrophysics Data System (ADS)

    Schiffman, C. R.; Mildor, B. S.; Bilham, R. G.

    2010-12-01

    Shortly after the 12 January 2010 Haiti earthquake, we installed an array of five tide gauges to determine sea level and its variability in the region of uplifted corals on the coast SW of Leogane, Haiti, that had been uplift ≤30 cm during the earthquake. Each gauge consists of a pressure transducer bolted 50-80 cm below mean sea level, which samples the difference between atmospheric pressure and sea pressure every 10 minutes. The data are transmitted via the Iridium satellite and are publically available with a latency of 10 minutes to 2 hours. The measurements reveal a maximum tidal range of ≈50 cm with 2-4 week oscillations in mean sea level of several cm. Sea slope, revealed by differences between adjacent gauges, varies 2-5 cm per 10 km at periods of 2-5 weeks, which imposes a disappointing limit to the utility of the gauges in estimating post seismic vertical motions. A parallel study of the form and elevation of coastal notches and mushroom rocks (rocks notched on all sides, hence forming a mushroom shape), along the coast west of Petit Goave suggests that these notches may provide an uplift history of the region over the past several hundreds of years. Notch sections in two areas were contoured, digitized, and compared to mean sea level. The notches mimic the histogram of sea level, suggesting that they are formed by dissolution by acidic surface waters. Notches formed two distinct levels, one approximately 58 cm above mean sea level, and the other approximately 157 cm above mean sea level. Several landslide blocks fell into the sea during the 2010 earthquake, and we anticipate these are destined for conversion to future mushroom rocks. Surfaces have been prepared on these blocks to study the rate of notch formation in situ, and samples are being subjected to acid corrosion in laboratory conditions, with the hope that the depth of notches may provide an estimate of the time of fall of previous rocks to help constrain the earthquake history of this area. A provisional interpretation is that this segment of the Haiti coastline was subjected to Intensity VIII shaking and rose 58 cm in the January 2010 earthquake. A previous earthquake presumably caused uplift of ≈1 m at this location, but we cannot constrain its date at present.

  19. Dirac Sea and its Evolution

    NASA Astrophysics Data System (ADS)

    Volfson, Boris

    2013-09-01

    The hypothesis of transition from a chaotic Dirac Sea, via highly unstable positronium, into a Simhony Model of stable face-centered cubic lattice structure of electrons and positrons securely bound in vacuum space, is considered. 13.75 Billion years ago, the new lattice, which, unlike a Dirac Sea, is permeable by photons and phonons, made the Universe detectable. Many electrons and positrons ended up annihilating each other producing energy quanta and neutrino-antineutrino pairs. The weak force of the electron-positron crystal lattice, bombarded by the chirality-changing neutrinos, may have started capturing these neutrinos thus transforming from cubic crystals into a quasicrystal lattice. Unlike cubic crystal lattice, clusters of quasicrystals are "slippery" allowing the formation of centers of local torsion, where gravity condenses matter into galaxies, stars and planets. In the presence of quanta, in a quasicrystal lattice, the Majorana neutrinos' rotation flips to the opposite direction causing natural transformations in a category comprised of three components; two others being positron and electron. In other words, each particle-antiparticle pair "e-" and "e+", in an individual crystal unit, could become either a quasi- component "e- ve e+", or a quasi- component "e+ - ve e-". Five-to-six six billion years ago, a continuous stimulation of the quasicrystal aetherial lattice by the same, similar, or different, astronomical events, could have triggered Hebbian and anti-Hebbian learning processes. The Universe may have started writing script into its own aether in a code most appropriate for the quasicrystal aether "hardware": Eight three-dimensional "alphabet" characters, each corresponding to the individual quasi-crystal unit shape. They could be expressed as quantum Turing machine qubits, or, alternatively, in a binary code. The code numerals could contain terminal and nonterminal symbols of the Chomsky's hierarchy, wherein, the showers of quanta, forming the cosmic microwave background radiation, may re-script a quasi-component "e- ve e+" (in the binary code case, same as numeral "0") into a quasi-component "e+ -ve e-" (numeral "1"), or vice versa. According to both, the Chomsky"s logic, and the rules applicable to Majorana particles, terminals "e-" and "e+" cannot be changed using the rules of grammar, while nonterminals "ve" and "-ve" can. Under "quantum" showers, the quasi- unit cells re-shape, resulting in re-combination of the clusters that they form, with the affected pattern become same as, similar to, or different from, other pattern(s). The process of self-learning may have occurred as a natural response to various astronomical events and cosmic cataclysms: The same astronomical activity in two different areas resulted in the emission of the same energy forming the same secondary quasicrystal pattern. Different but similar astronomical activity resulted in the emission of a similar amount of energy forming a similar secondary quasicrystal pattern. Different astronomical activity resulted in the emission of a different amount of energy forming a different secondary quasicrystal pattern. Since quasicrystals conduct energy in one direction and don't conduct energy in the other, the control over quanta flows allows aether to scribe a script onto itself through changing its own quasi- patterns. The paper, as published below, is a lecture summary. The full text is published on website: www.borisvolfson.org

  20. The Satellite Passive-Microwave Record of Sea Ice in the Ross Sea Since Late 1978

    NASA Technical Reports Server (NTRS)

    Parkinson, Claire L.

    2009-01-01

    Satellites have provided us with a remarkable ability to monitor many aspects of the globe day-in and day-out and sea ice is one of numerous variables that by now have quite substantial satellite records. Passive-microwave data have been particularly valuable in sea ice monitoring, with a record that extends back to August 1987 on daily basis (for most of the period), to November 1970 on a less complete basis (again for most of the period), and to December 1972 on a less complete basis. For the period since November 1970, Ross Sea sea ice imagery is available at spatial resolution of approximately 25 km. This allows good depictions of the seasonal advance and retreat of the ice cover each year, along with its marked interannual variability. The Ross Sea ice extent typically reaches a minimum of approximately 0.7 x 10(exp 6) square kilometers in February, rising to a maximum of approximately 4.0 x 10(exp 6) square kilometers in September, with much variability among years for both those numbers. The Ross Sea images show clearly the day-by-day activity greatly from year to year. Animations of the data help to highlight the dynamic nature of the Ross Sea ice cover. The satellite data also allow calculation of trends in the ice cover over the period of the satellite record. Using linear least-squares fits, the Ross Sea ice extent increased at an average rate of 12,600 plus or minus 1,800 square kilometers per year between November 1978 and December 2007, with every month exhibiting increased ice extent and the rates of increase ranging from a low of 7,500 plus or minus 5,000 square kilometers per year for the February ice extents to a high of 20,300 plus or minus 6,100 kilometers per year for the October ice extents. On a yearly average basis, for 1979-2007 the Ross Sea ice extent increased at a rate of 4.8 plus or minus 1.6 % per decade. Placing the Ross Sea in the context of the Southern Ocean as a whole, over the November 1978-December 2007 period the Ross Sea had the highest rate of increase in sea ice coverage of any of five standard divisions of the Southern Ocean, although the Weddell Sea, Indian Ocean, and Western Pacific Ocean all also had sea ice increases, while only the Bellingshausen/Smundsen Seas experienced overall sea ice decreases. Overall, the Southern Ocean sea ice cover increased at an average rate of 10,800 plus or minus 2,500 square kilometers per year between November 1978 and December 2007, with every month showing positive values although with some of these values not being statistically significant. The sea ice increase since November 1978 was preceded by a sharp decrease in Southern Ocean ice coverage in the 1970's and is in marked contrast to the decrease in Arctic sea ice coverage that has occurred both in the period since November 1978 and since earlier in the 1970's. On a yearly average bases, for 1979-2007 the Southern Ocean sea ice extent increased at a rate of 1.0 plus or minus 0.4% per decade, whereas the Arctic ice extent decreased at the much greater rate of 4.0 plus or minus 0.4 percent per decade (closer to the % per decade rate of increase in the Ross Sea). Considerable research is ongoing to explain the differences.

  1. Giant virus in the sea

    PubMed Central

    Claverie, Jean-Michel

    2013-01-01

    The viral nature of the first “giant virus,” Mimivirus, was realized in 2003, 10 y after its initial isolation from the water of a cooling tower in Bradford, UK. Soon after its genome was sequenced, the mining of the Global Ocean Sampling environmental sequence database revealed that the closest relatives of Mimivirus, only known to infect Acanthamoeba, were to be found in the sea. These predicted marine Mimivirus relatives remained elusive until 2010, with the first genomic characterization of a virus infecting a heterotrophic unicellular eukaryote, the microflagellate grazer Cafeteria roenbergensis. The genome analysis of a virus (PgV) infecting the common unicellular algae Phaeocystis globosa now shows that it is a bona fide member of the Mimivirus family (i.e., the Megaviridae), extending the realm of these giant viruses to abundant blooming phytoplankton species. Despite its smaller genome size (460 kb encoding 434 proteins), PgV exhibits the most intriguing feature of the previously characterized Megaviridae: an associated virophage. However, the 19-kb virophage genome, devoid of a capsid gene, is packaged in the PgV particle and propagated as a “viral plasmid,” the first ever described. The PgV genome also exhibits the duplication of “core genes,” normally present as single copies and a putative new type of mobile element. In a DNA polymerase phylogeny including representatives of the three cellular domains, PgV and the other Megaviridae cluster into their own clade deeply branching between domains Archaea and Eukarya domains, thus exhibiting the topology of a fourth domain in the Tree of Life. PMID:24563700

  2. The results of measurements of heavy metals in atmospheric aerosols in the open areas of the Arctic Seas in 2009-2010

    NASA Astrophysics Data System (ADS)

    Golubeva, N. I.; Burtseva, L. V.; Matishov, G. G.; Il'in, G. V.

    2013-11-01

    By experimental data on the concentration of toxic microelements (Pb, Cd, Cu, Zn, Ni, Co, and Cr) in atmospheric aerosols over the White and Norwegian Seas in winter-spring period of 2009-2010, the contamination of air environment over two sea basins, significantly different by geographical conditions but being heavily impacted by North-European industrial centres, including the impact of the largest in the European Arctic Kola industrial centre, has been analyzed. It has been indicated and described that the air basin over the White Sea water area, when compared to the Norwegian Sea, is under a significantly greater impact of the emission sources of heavy metals, located on the Kola Peninsula.

  3. Identification of paleo Arctic winter sea ice limits and the marginal ice zone: Optimised biomarker-based reconstructions of late Quaternary Arctic sea ice

    NASA Astrophysics Data System (ADS)

    Belt, Simon T.; Cabedo-Sanz, Patricia; Smik, Lukas; Navarro-Rodriguez, Alba; Berben, Sarah M. P.; Knies, Jochen; Husum, Katrine

    2015-12-01

    Analysis of >100 surface sediments from across the Barents Sea has shown that the relative abundances of the mono-unsaturated sea ice diatom-derived biomarker IP25 and a tri-unsaturated highly branched isoprenoid (HBI) lipid (HBI III) are characteristic of the overlying surface oceanographic conditions, most notably, the location of the seasonal sea ice edge. Thus, while IP25 is generally limited to locations experiencing seasonal sea ice, with higher abundances found for locations with longer periods of ice cover, HBI III is found in sediments from all sampling locations, but is significantly enhanced in sediments within the vicinity of the retreating sea ice edge or marginal ice zone (MIZ). The response of HBI III to this well-defined sea ice scenario also appears to be more selective than that of the more generic phytoplankton biomarker, brassicasterol. The potential for the combined analysis of IP25 and HBI III to provide more detailed assessments of past sea ice conditions than IP25 alone has been investigated by quantifying both biomarkers in three marine downcore records from locations with contrasting modern sea ice settings. For sediment cores from the western Barents Sea (intermittent seasonal sea ice) and the northern Norwegian Sea (ice-free), high IP25 and low HBI III during the Younger Dryas (ca. 12.9-11.9 cal. kyr BP) is consistent with extensive sea cover, with relatively short periods of ice-free conditions resulting from late summer retreat. Towards the end of the YD (ca. 11.9-11.5 cal. kyr BP), a general amelioration of conditions resulted in a near winter maximum ice edge scenario for both locations, although this was somewhat variable, and the eventual transition to predominantly ice-free conditions was later for the western Barents Sea site (ca. 9.9 cal. kyr BP) compared to NW Norway (ca. 11.5 cal. kyr BP). For both locations, coeval elevated HBI III (but absent IP25) potentially provides further evidence for increased Atlantic Water inflow during the early Holocene, but this interpretation requires further investigation. In contrast, IP25 and HBI III data obtained from a core from the northern Barents Sea demonstrate that seasonal sea ice prevailed throughout the Holocene, but with a gradual shift from winter ice edge conditions during the early Holocene to more sustained ice cover in the Neoglacial; a directional shift that has undergone a reverse in the last ca. 150 yr according to observational records. Our combined surface and downcore datasets suggest that combined analysis of IP25 and HBI III can provide information on temporal variations in the position of the maximum (winter) Arctic sea ice extent, together with insights into sea ice seasonality by characterisation of the MIZ. Combining IP25 with HBI III in the form of the previously proposed PIP25 index yields similar outcomes to those obtained using brassicasterol as the phytoplankton marker. Importantly, however, some problems associated with use of a variable balance factor employed in the PIP25 calculation, are potentially alleviated using HBI III.

  4. From sea to sea: Canada's three oceans of biodiversity.

    PubMed

    Archambault, Philippe; Snelgrove, Paul V R; Fisher, Jonathan A D; Gagnon, Jean-Marc; Garbary, David J; Harvey, Michel; Kenchington, Ellen L; Lesage, Véronique; Levesque, Mélanie; Lovejoy, Connie; Mackas, David L; McKindsey, Christopher W; Nelson, John R; Pepin, Pierre; Piché, Laurence; Poulin, Michel

    2010-01-01

    Evaluating and understanding biodiversity in marine ecosystems are both necessary and challenging for conservation. This paper compiles and summarizes current knowledge of the diversity of marine taxa in Canada's three oceans while recognizing that this compilation is incomplete and will change in the future. That Canada has the longest coastline in the world and incorporates distinctly different biogeographic provinces and ecoregions (e.g., temperate through ice-covered areas) constrains this analysis. The taxonomic groups presented here include microbes, phytoplankton, macroalgae, zooplankton, benthic infauna, fishes, and marine mammals. The minimum number of species or taxa compiled here is 15,988 for the three Canadian oceans. However, this number clearly underestimates in several ways the total number of taxa present. First, there are significant gaps in the published literature. Second, the diversity of many habitats has not been compiled for all taxonomic groups (e.g., intertidal rocky shores, deep sea), and data compilations are based on short-term, directed research programs or longer-term monitoring activities with limited spatial resolution. Third, the biodiversity of large organisms is well known, but this is not true of smaller organisms. Finally, the greatest constraint on this summary is the willingness and capacity of those who collected the data to make it available to those interested in biodiversity meta-analyses. Confirmation of identities and intercomparison of studies are also constrained by the disturbing rate of decline in the number of taxonomists and systematists specializing on marine taxa in Canada. This decline is mostly the result of retirements of current specialists and to a lack of training and employment opportunities for new ones. Considering the difficulties encountered in compiling an overview of biogeographic data and the diversity of species or taxa in Canada's three oceans, this synthesis is intended to serve as a biodiversity baseline for a new program on marine biodiversity, the Canadian Healthy Ocean Network. A major effort needs to be undertaken to establish a complete baseline of Canadian marine biodiversity of all taxonomic groups, especially if we are to understand and conserve this part of Canada's natural heritage. PMID:20824204

  5. From Sea to Sea: Canada's Three Oceans of Biodiversity

    PubMed Central

    Archambault, Philippe; Snelgrove, Paul V. R.; Fisher, Jonathan A. D.; Gagnon, Jean-Marc; Garbary, David J.; Harvey, Michel; Kenchington, Ellen L.; Lesage, Véronique; Levesque, Mélanie; Lovejoy, Connie; Mackas, David L.; McKindsey, Christopher W.; Nelson, John R.; Pepin, Pierre; Piché, Laurence; Poulin, Michel

    2010-01-01

    Evaluating and understanding biodiversity in marine ecosystems are both necessary and challenging for conservation. This paper compiles and summarizes current knowledge of the diversity of marine taxa in Canada's three oceans while recognizing that this compilation is incomplete and will change in the future. That Canada has the longest coastline in the world and incorporates distinctly different biogeographic provinces and ecoregions (e.g., temperate through ice-covered areas) constrains this analysis. The taxonomic groups presented here include microbes, phytoplankton, macroalgae, zooplankton, benthic infauna, fishes, and marine mammals. The minimum number of species or taxa compiled here is 15,988 for the three Canadian oceans. However, this number clearly underestimates in several ways the total number of taxa present. First, there are significant gaps in the published literature. Second, the diversity of many habitats has not been compiled for all taxonomic groups (e.g., intertidal rocky shores, deep sea), and data compilations are based on short-term, directed research programs or longer-term monitoring activities with limited spatial resolution. Third, the biodiversity of large organisms is well known, but this is not true of smaller organisms. Finally, the greatest constraint on this summary is the willingness and capacity of those who collected the data to make it available to those interested in biodiversity meta-analyses. Confirmation of identities and intercomparison of studies are also constrained by the disturbing rate of decline in the number of taxonomists and systematists specializing on marine taxa in Canada. This decline is mostly the result of retirements of current specialists and to a lack of training and employment opportunities for new ones. Considering the difficulties encountered in compiling an overview of biogeographic data and the diversity of species or taxa in Canada's three oceans, this synthesis is intended to serve as a biodiversity baseline for a new program on marine biodiversity, the Canadian Healthy Ocean Network. A major effort needs to be undertaken to establish a complete baseline of Canadian marine biodiversity of all taxonomic groups, especially if we are to understand and conserve this part of Canada's natural heritage. PMID:20824204

  6. Assimilation of sea surface temperature, sea ice concentration and sea ice drift in a model of the Southern Ocean

    NASA Astrophysics Data System (ADS)

    Barth, Alexander; Canter, Martin; Van Schaeybroeck, Bert; Vannitsem, Stéphane; Massonnet, François; Zunz, Violette; Mathiot, Pierre; Alvera-Azcárate, Aida; Beckers, Jean-Marie

    2015-09-01

    Current ocean models have relatively large errors and biases in the Southern Ocean. The aim of this study is to provide a reanalysis from 1985 to 2006 assimilating sea surface temperature, sea ice concentration and sea ice drift. In the following it is also shown how surface winds in the Southern Ocean can be improved using sea ice drift estimated from infrared radiometers. Such satellite observations are available since the late seventies and have the potential to improve the wind forcing before more direct measurements of winds over the ocean are available using scatterometry in the late nineties. The model results are compared to the assimilated data and to independent measurements (the World Ocean Database 2009 and the mean dynamic topography based on observations). The overall improvement of the assimilation is quantified, in particular the impact of the assimilation on the representation of the polar front is discussed. Finally a method to identify model errors in the Antarctic sea ice area is proposed based on Model Output Statistics techniques using a series of potential predictors. This approach provides new directions for model improvements.

  7. Temporal variatiions of Sea ice cover in the Baltic Sea derived from operational sea ice products used in NWP.

    NASA Astrophysics Data System (ADS)

    Lange, Martin; Paul, Gerhard; Potthast, Roland

    2014-05-01

    Sea ice cover is a crucial parameter for surface fluxes of heat and moisture over water areas. The isolating effect and the much higher albedo strongly reduces the turbulent exchange of heat and moisture from the surface to the atmosphere and allows for cold and dry air mass flow with strong impact on the stability of the whole boundary layer and consequently cloud formation as well as precipitation in the downstream regions. Numerical weather centers as, ECMWF, MetoFrance or DWD use external products to initialize SST and sea ice cover in their NWP models. To the knowledge of the author there are mainly two global sea ice products well established with operational availability, one from NOAA NCEP that combines measurements with satellite data, and the other from OSI-SAF derived from SSMI/S sensors. The latter one is used in the Ostia product. DWD additionally uses a regional product for the Baltic Sea provided by the national center for shipping and hydrografie which combines observations from ships (and icebreakers) for the German part of the Baltic Sea and model analysis from the hydrodynamic HIROMB model of the Swedish meteorological service for the rest of the domain. The temporal evolution of the three different products are compared for a cold period in Februar 2012. Goods and bads will be presented and suggestions for a harmonization of strong day to day jumps over large areas are suggested.

  8. Assimilation of sea surface temperature, sea ice concentration and sea ice drift in a model of the Southern Ocean

    NASA Astrophysics Data System (ADS)

    Barth, Alexander; Canter, Martin; Van Schaeybroeck, Bert; Vannitsem, Stéphane; Massonnet, François; Zunz, Violette; Mathiot, Pierre; Alvera-Azcárate, Aida; Beckers, Jean-Marie

    2015-04-01

    Current ocean models have relatively large errors and biases in the Southern Ocean. The aim of this study is to provide a reanalysis from 1985 to 2006 assimilating sea surface temperature, sea ice concentration and sea ice drift. In the following it is also shown how surface winds in the Southern Ocean can be improved using sea ice drift estimated from infrared radiometers. Such satellite observations are available since the late seventies and have the potential to improve the wind forcing before more direct measurements of winds over the ocean are available using scatterometry in the late nineties. The model results are compared to the assimilated data and to independent measurements (the World Ocean Database 2009 and the mean dynamic topography based on observations). The overall improvement of the assimilation is quantified, in particular the impact of the assimilation on the representation of the polar front is discussed. Finally a method to identify model errors in the Antarctic sea ice area is proposed based on Model Output Statistics techniques using a series of potential predictors. This approach provides new directions for model improvements.

  9. Sea Sources. Bibliographic and Resource Material of Children's Literature of the Sea.

    ERIC Educational Resources Information Center

    Bagnall, Norma

    Writers have often used the sea as background or as a theme in writing for children since it is a natural setting for adventure or exploration and has an attractiveness for all of us. Included in this bibliography is a representative listing of books related to the seas and inland waters, individual stories and poems which have a bearing on sea…

  10. Recent and projected changes in Dead Sea level and effects on mineral production from the sea

    USGS Publications Warehouse

    Sauer, Stanley P.

    1978-01-01

    Hydrologic data for the Dead Sea area were reviewed to assess the probable magnitude and rate of change of the water level of the Sea. Historical average annual Dead Sea levels range from a minimum of 399.4 meters below sea level in about 1818 to a maximum of 388.6 meters below in 1896. Present levels are rapidly approaching the historical low. There is a close correlation between Dead Sea level and accumulated departure from the mean of long-term rainfall except for the most recent period since 1964. During that period rainfall has been near the long-term average but water levels have continued to decline, in part due to abstractions for irrigation in the Jordan River basin. The dissolved-solids concentration of Dead Sea water presently is approximately 322,000 milligrams per liter and is generally well mixed. The increase in dissolved solids to the present high concentration has resulted in an evaporation rate less than that estimated in previous reports. An average annual inflow to the Sea of 900 cubic hectometers from all sources is required to stabilize the Sea at the present level. (Woodard-USGS)

  11. Standardization of electromagnetic-induction measurements of sea-ice thickness in polar and subpolar seas

    NASA Astrophysics Data System (ADS)

    Tateyama, K.; Shirasawa, K.; Uto, S.; Kawamura, T.; Toyota, T.; Enomoto, H.

    Electromagnetic-induction (EM) instruments can be used to estimate sea-ice thickness because of the large contrast in the conductivities of sea ice and sea water, and are currently used in investigations of sea-ice thickness. In this study we analyze several snow, ice and sea-water samples and attempt to derive an appropriate formula to transform the apparent conductivity obtained from EM measurements to the total thickness of snow and ice for all regions and seasons. This was done to simplify the EM tuning procedure. Surface EM measurement transects with the instrument at varying heights above the ice were made in the Chukchi Sea, off East Antarctica, in the Sea of Okhotsk and in Saroma-ko (lagoon). A standardized transformation formula based on a one-dimensional multi-layer model was developed that also considers the effects of water-filled gaps between deformed ice, a saline snow slush layer, and the increase in the footprint size caused by increasing the instrument height. The overall average error in ice thickness determined with the standardized transform was <7%, and the regional average errors were 2.2% for the Arctic, 7.0% for the Antarctic, 6.5% for the Sea of Okhotsk and 4.4% for Saroma-ko.

  12. How Much Are Floridians Willing to Pay for Protecting Sea Turtles from Sea Level Rise?

    NASA Astrophysics Data System (ADS)

    Hamed, Ahmed; Madani, Kaveh; Von Holle, Betsy; Wright, James; Milon, J. Walter; Bossick, Matthew

    2016-01-01

    Sea level rise (SLR) is posing a great inundation risk to coastal areas. Some coastal nesting species, including sea turtle species, have experienced diminished habitat from SLR. Contingent valuation method (CVM) was used in an effort to assess the economic loss impacts of SLR on sea turtle nesting habitats for Florida coasts; and to elicit values of willingness to pay (WTP) of Central Florida residents to implement certain mitigation strategies, which would protect Florida's east coast sea turtle nesting areas. Using the open-ended and dichotomous choice CVM, we sampled residents of two Florida communities: Cocoa Beach and Oviedo. We estimated the WTP of households from these two cities to protect sea turtle habitat to be between 42 and 57 per year for 5 years. Additionally, we attempted to assess the impact of the both the respondents' demographics and their perception toward various situations on their WTP value. Findings include a negative correlation between the age of a respondent and the probability of an individual willing to pay the hypothetical WTP amount. We found that WTP of an individual was not dependent on prior knowledge of the effects of SLR on sea turtle habitat. The greatest indicators of whether or not an individual was willing to pay to protect sea turtle habitat were the respondents' perception regarding the trustworthiness and efficiency of the party which will implement the conservation measures and their confidence in the conservation methods used. Respondents who perceive sea turtles having an effect on their life were also more likely to pay.

  13. "The Mirror of the Sea": Narrative Identity, Sea Kayak Adventuring and Implications for Outdoor Adventure Education

    ERIC Educational Resources Information Center

    Miles, Beau; Wattchow, Brian

    2015-01-01

    This paper explores the complex and changing nature of adventure as a form of cultural practice. Borrowing from Joseph Conrad's memoirs "The Mirror of The Sea" (1907), sea kayaking is contextualized here as a journey that takes place just as much between "landfall and departure" as it does between the paddler's ears (i.e., in…

  14. Long-term variability and trends of sea level storminess and extremes in European Seas

    NASA Astrophysics Data System (ADS)

    Vilibić, Ivica; Šepić, Jadranka

    2010-03-01

    This paper documents the variability and trends of mean storminess and extreme sea level amplitudes at selected long-term operating tide gauge stations located in the European Seas over different frequency bands, seasons and months. Six stations have been chosen for the analyses-Antalya, Ceuta, Rovinj, Newlyn, Wladyslawowo and Lerwick-which possess at least a half-centurial record of hourly or higher frequency sea level data. The data have been carefully inspected for time shifts and drifts in the record. The analyses included the extraction of sea level amplitudes (envelopes) over four frequency bands: super-diurnal frequencies (0-1 days), small-scale synoptic disturbances (1-3 days), large-scale synoptic disturbances (3-10 days) and planetary-scale disturbances (10-100 days). Interannual variability in sea level amplitudes is occasionally found to coincide with some known variability in the atmosphere. For example, the northern European stations have overall positive sea level storminess and extreme trends, which is opposite from the southern stations, confirming a northward shift in atmosphere storm tracks. Redistribution of sea level amplitudes between different seasons and different frequency bands has been observed at some stations in both variability and trends. The latter may be important for the assessment of a region's total hazard risks and vulnerability, as maximum storminess and extremes may or may not coincide with maximum mean sea level.

  15. Sea ice thickness in the Weddell Sea, inferred from upward looking sonar measurements

    NASA Astrophysics Data System (ADS)

    Behrendt, Axel; Dierking, Wolfgang; Witte, Hannelore

    2014-05-01

    Sea ice has been routinely monitored by satellites since 1979. However, thickness measurements of sea ice are still very sparse, especially in the Southern Hemisphere. Satellite altimetry still provides relatively uncertain estimates of ice thickness. Today, the only tool for monitoring sea ice thickness over long time periods with highest accuracy (5-10 cm) are moored upward looking sonars (ULS). The instruments measure the subsurface portion (draft) of the ice, which can be converted into total ice thickness. We present a data set of ULS time series from 13 positions in the Atlantic sector of the Southern Ocean (Weddell Sea), which were made in different years between 1990 and 2010. Monthly mean sea ice draft shows high interannual variability and can reach more than 3 m in the dynamic coastal regions of the eastern and western Weddell Sea. The thinnest ice is found away from the coast in the eastern Weddell Sea and rarely exceeds 1 m in the monthly mean. In single years the ULS data allow for a clear discrimination between thermodynamic ice growth and dynamic ice growth due to rafting and ridging of the floes. We demonstrate that the thermodynamic ice thickness can reach its theoretical maximum value of 1 m in the central Weddell basin. Despite significant gaps, the presented data set provides an important validation tool for satellite algorithms and sea ice models.

  16. Assessment of MERIS reflectance data as processed with SeaDAS over the European seas.

    PubMed

    Mélin, Frédéric; Zibordi, Giuseppe; Berthon, Jean-François; Bailey, Sean; Franz, Bryan; Voss, Kenneth; Flora, Stephanie; Grant, Mike

    2011-12-01

    The uncertainties associated with MERIS remote sensing reflectance (RRS) data derived from the SeaWiFS Data Analysis System (SeaDAS) are assessed with field observations. In agreement with the strategy applied for other sensors, a vicarious calibration is conducted using in situ data from the Marine Optical BuoY offshore Hawaii, and leads to vicarious adjustment factors departing from 1 by 0.2% to 1.6%. The three field data sets used for validation have been collected at fixed stations in the northern Adriatic Sea and the Baltic Sea, and in a variety of European waters in the Baltic, Black, Mediterranean and North Seas. Excluding Baltic waters, the mean absolute relative difference |ψ| between satellite and field data is 10-14% for the spectral interval 490-560 nm, 16-18% at 443 nm, and 24-26% at 413 nm. In the Baltic Sea, the |ψ| values are much higher for the blue bands characterized by low RRS amplitudes, but similar or lower at 560 and 665 nm. For the three validation sets, the root-mean-square differences decrease from approximately 0.0013 sr-1 at 413 nm to 0.0002 sr-1 at 665 nm, and are found similar or lower than those obtained for SeaWiFS or MODIS-Aqua. As derived from SeaDAS, the RRS records associated with these three missions thus provide a multi-mission data stream of consistent accuracy. PMID:22273959

  17. 50 CFR 697.12 - At-sea sea sampler/observer coverage.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 50 Wildlife and Fisheries 13 2013-10-01 2013-10-01 false At-sea sea sampler/observer coverage. 697.12 Section 697.12 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION, DEPARTMENT OF COMMERCE (CONTINUED) ATLANTIC COASTAL FISHERIES COOPERATIVE MANAGEMENT General Provisions § 697.12...

  18. Imperial Valley and Salton Sea, California

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Southern California's Salton Sea is a prominent visual for astronauts. This large lake supports the rich agricultural fields of the Imperial, Coachella and Mexicali Valleys in the California and Mexico desert. The Salton Sea formed by accident in 1905 when an irrigation canal ruptured, allowing the Colorado River to flood the Salton Basin. Today the Sea performs an important function as the sink for agricultural runoff; water levels are maintained by the runoff from the surrounding agricultural valleys. The Salton Sea salinity is high-nearly 1/4 saltier than ocean water-but it remains an important stopover point for migratory water birds, including several endangered species. The region also experiences several environmental problems. The recent increased demands for the limited Colorado River water threatens the amount of water allowed to flow into the Salton Sea. Increased salinity and decreased water levels could trigger several regional environmental crises. The agricultural flow into the Sea includes nutrients and agricultural by-products, increasing the productivity and likelihood of algae blooms. This image shows either a bloom, or suspended sediment (usually highly organic) in the water that has been stirred up by winds. Additional information: The Salton Sea A Brief Description of Its Current Conditions, and Potential Remediation Projects and Land Use Across the U.S.-Mexico Border Astronaut photograph STS111-E-5224 was taken by the STS-111 Space Shuttle crew that recently returned from the International Space Station. The image was taken June 12, 2002 using a digital camera. The image was provided by the Earth Sciences and Image Analysis Laboratory at Johnson Space Center. Additional images taken by astronauts and cosmonauts can be viewed at the NASA-JSC Gateway to Astronaut Photography of Earth.

  19. Decline of the Black Sea oxygen inventory

    NASA Astrophysics Data System (ADS)

    Capet, Arthur; Stanev, Emil V.; Beckers, Jean-Marie; Murray, James W.; Grégoire, Marilaure

    2016-03-01

    We show that from 1955 to 2015, the inventory of oxygen in the Black Sea has decreased by 44 % and the basin-averaged oxygen penetration depth has decreased from 140 m in 1955 to 90 m in 2015, which is the shallowest annual value recorded during that period. The oxygenated Black Sea surface layer separates the world's largest reservoir of toxic hydrogen sulfide from the atmosphere. The threat of chemocline excursion events led to hot debates in the past decades arguing on the vertical stability of the Black Sea oxic/suboxic interface. In the 1970s and 1980s, when the Black Sea faced severe eutrophication, enhanced respiration rates reduced the thickness of the oxygenated layer. Re-increasing oxygen inventory in 1985-1995 supported arguments in favor of the stability of the oxic layer. Concomitant with a reduction of nutrient loads, it also supported the perception of a Black Sea recovering from eutrophication. More recently, atmospheric warming was shown to reduce the ventilation of the lower oxic layer by lowering cold intermediate layer (CIL) formation rates. The debate on the vertical migration of the oxic interface also addressed the natural spatial variability affecting Black Sea properties when expressed in terms of depth. Here we show that using isopycnal coordinates does not overcome the significant spatial variability of oxygen penetration depth. By considering this spatial variability, the analysis of a composite historical set of oxygen profiles evidenced a significant shoaling of the oxic layer, and showed that the transient "recovery" of the 1990s was mainly a result of increased CIL formation rates during that period. As both atmospheric warming and eutrophication are expected to increase in the near future, monitoring the dynamics of the Black Sea oxic layer is urgently required to assess the threat of further shoaling.

  20. Zaliv Kara-Bogaz-Gol, Caspian Sea

    NASA Technical Reports Server (NTRS)

    2002-01-01

    The large eastern embayment of the Caspian Sea, the Zaliv Kara-Bogaz-Gol, provides astronauts the chance to observe several oceanographic phenomena. This view taken by the STS-111 crew from the Space Shuttle in June 2002 shows the sun reflecting off the surface waters that surround the spit that defines the Zaliv Kara-Bogaz-Gol from the open Caspian Sea. The sunglint reveals the flow of fresher water through the spit channel and into the bay. Old shorelines and accretionary features can be seen on the spit, as well as the dam that was constructed in 1980 to stop the flow into the lower Kara-Bogaz-Gol basin. The Caspian Sea has experienced dramatic changes in water levels throughout the past 100 years. From the 1930s until 1978, the water levels in the Caspian had dropped nearly 3 m. In 1980, in response to the rapidly dropping sea level, a dam was constructed to prevent water from flowing into the shallow and restricted Kara-Bogaz-Gol basin, resulting in the drying up of the bay. The dam was partially opened a few years later, and completely opened in 1992 when Caspian water levels started to rise quickly. Today, sea levels are more than 2.6 m higher than the 1978 levels, and, as shown here, water flows freely into the salty waters of the Zaliv Kara-Bogaz-Gol. Astronauts have also been documenting the coastlines around the Caspian Sea that have been impacted by the large sea level fluctuations. Astronaut photograph STS111-E-5485 was provided by the Earth Sciences and Image Analysis Laboratory at Johnson Space Center. Additional images taken by astronauts and cosmonauts can be viewed at the NASA-JSC Gateway to Astronaut Photography of Earth.