To see the other types of publications on this topic, follow the link: Oceana.
Dissertations / Theses on the topic 'Oceana'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 50 dissertations / theses for your research on the topic 'Oceana.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse dissertations / theses on a wide variety of disciplines and organise your bibliography correctly.
1
Anders, Signahl, and Hjerpe Nils. "Deep Green i oceana strömmar - en konceptstudie." Thesis, Linköping University, Machine Design, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-57829.
Full textAbstract:
With growing economies and better living standards in many parts of the world today, there is a need of expanding the capacity of generating electricity. The alternatives for renewable energy technologies are not fully developed and have still some problems to conquer.
The company Minesto has developed a technology that is called Deep Green. It is designed to gain electricity from tidal currents. Deep Green works in a similar way as a kite that is attached to the seafloor with a moving wire. It contains of a wing that moves due to the water current. The path of the movement is circular or a shape of an “8”. The turbine under the wing is powered by the water flow which in turn leads to generation of electricity by the generator.
The purpose of this thesis is to investigate the potential of using the Deep Green technology in ocean currents with respect to construction and economy. The site for the investigation is off the east coast of Florida where the Florida current streams with a speed of about 1, 5 m/s close to the surface. The major difference compared to the use in tidal currents is the deep waters of about 300 m and a oneway current direction.
A mooring construction was developed and optimized and with the use of carbon fiber ropes, buoys and foundations lets 9 Deep Greens operate between 20 and 79 m depth. The idea is to install 7 such clusters with a total of 63 Deep Greens on the site in Florida. This configuration generates a power of 24 MW and gives a production of 185 GWh/year.
Economic accounts were made with support of earlier made calculations regarding a park of 60 Deep Greens in a tidal current application. The results for the clustered configuration in ocean currents indicated a cost of 0,67 SEK/kWh with a discount rate of 8%. The required capital for the installation is about 780 mSEK (CAPEX). The operating costs (OPEX) are 43,3 mSEK.
The design seems reasonable in many respects and it operates in a continuous ocean current with good electricity generation. The use of Deep Green in ocean currents speaks for being a profitable application. Though, it will be a large‐scale economic project, mainly because installations in a small scale will not be profitable due to costs such as grid connection.
Critical issues to look at in a further development was considered to be surveys of the installation site, the displacement and movements of the mooring, the buoyancy‐system and the installation procedure.
2
Clarkson, Elizabeth A. "Hazardous waste reduction Naval Air Station Oceana." Thesis, Springfield, Virginia: Available from National Technical Information Service, 1991. http://hdl.handle.net/10945/28256.
Full text
3
Geiser, Matthew T. "Improving Aircraft Refueling Procedures at Naval Air Station Oceana." Thesis, Monterey, California. Naval Postgraduate School, 2012. http://hdl.handle.net/10945/7346.
Full textAbstract:
This thesis seeks to improve aircraft refueling at Naval Air Station (NAS) Oceana, VA, using aircraft waiting time for fuel as a measure of performance. We develop a computer-assisted discrete-event simulation to model refueling at NAS Oceana using airfield data from October 2011. Our study focuses on six factors: the total number of mobile refueling trucks, the rate of fuel flow from each truck, the quality of information sharing, the percentage of aircraft that refuel using hot pits (high-speed, in-ground refueling stations), and the normal operating band (both the upper limit and the lower limit) of jet fuel level that each truck driver maintains. We use experimental design and determine the efficiency of various decisions for reducing fuel wait time. We conclude with specific recommendations for NAS Oceana leadership.
4
Mallory, William, Rich Rivera, William Swinford, and BRB Consulting. "Improving Utilization of F/A-18 Simulator CUBIC Instructors at VFA-106, Naval Air Station Oceana, VA." Thesis, Monterey, California. Naval Postgraduate School, 2010. http://hdl.handle.net/10945/7062.
Full textAbstract:
EMBA Project ReportEXECUTIVE SUMMARY: Strike Fighter Squadron ONE ZERO SIX (VFA-106), the only East Coast F/A-18 Fleet Replacement Squadron (FRS), has identified problems in Cubic Instructor (CI) capacity during periods of high demand as a result of combining series of aircraft, C/D and E/F, into larger “Super” classes. Subsequently, the squadron is forced to augment CIs with Instructor Pilots (IPs) or Instructor Weapons System Officers (IWSOs) to increase capacity or forego utilization of some of their 70 simulator hours allotted to them daily. A simulator process improvement study was undertaken to help VFA-106 address these issues, ultimately improving production and time-to-train. FINDINGS • The current CI contract is inefficient due to its inflexibility • Simply increasing CI manning is not a long-term solution • The current VFA-106 simulator scheduling construct is insufficient and lacks long-term vision RECOMMENDATIONS • Draft and utilize a more flexible CI contract • Institute simulator scheduling process improvements to provide more continuity and a long-term vision
5
de, Lannoy Jean. "Through the vale of darkness : history in South Malakula, Vanuatu." Thesis, University of Oxford, 2004. http://ora.ox.ac.uk/objects/uuid:57eb5894-fe4c-440a-843f-fe195d4239d0.
Full textAbstract:
The thesis is a multi-vocal and localized history of the destruction of ancient Malakulan society through depopulation, migration and conversion, of the salvation of some people who gathered around Christian communities, and of the relationship of these people and their descendants to the places they have left and to the communities in which they now live. The thesis brings a historical perspective to Vanuatu anthropology. Compared to earlier work in anthropological history in the Pacific by Sahlins, Dening and Bronwen Douglas, the main innovation in method is that all historical statements are set in their context, emphasizing the multiplicity of view points and revealing the significance of even minor variations which refer to important local issues, from land disputes to conversion to Christianity. Innovative use is made of funerary inscriptions, local maps and court archives, reflecting local forms of historical literacy. The research is part of a growing interest in Christianity in Oceania, after a long neglect by anthropologists. This is the first historical anthropology of Vanuatu and perhaps Melanesia to consider the long-term social impact of the dramatic depopulation that accompanied the colonial expansion of Europeans. The abandonment of the interior of the island of Malakula and the weakening of traditional links with other islands have reduced the social space of Malakula to the original zone of contact with Europeans, the coastal areas and nearby small islands. I argue that Christianity allowed the people of Malakula to create a new form of sociality in response to these events. The new society has its own time and space organized around the nuclear family meal and Sunday service, which were the two cornerstones of the conversion process, symbolizing the abandonment of former ritual activities and of the segregation of cooking fires according to ritual status. This process of cultural adaptation continues with the appropriation by villagers of the historical perspective of official courts favouring material evidence and legalistic principles in land disputes. Earlier research on Vanuatu was dominated by the themes of 'kastom', a discourse on tradition opposed to Western ways, and of the rootedness of people in place. This double emphasis is linked to the fact that most fieldwork in the country was done in the 1970s before a fifteen years ban on foreign research after Independence in 1980. In the context of the struggle for Independence and the restitution of alienated land, Vanuatu people needed to emphasize indigenous values and attachment to land. Today, priorities on the ground have changed and new types of discourses have come to the fore emphasizing conversion to Christianity and adopting new concepts reflecting a shift in preoccupation from recovering colonial land to the relation between indigenous Christian migrants and original owners.
6
Hayduk, Ulf Christoph. "Hopeful Politics: The Interregnum Utopias." Thesis, The University of Sydney, 2005. http://hdl.handle.net/2123/703.
Full textAbstract:
The period of English history between the second Civil War and the Restoration opened up seemingly unlimited possibilities for shaping the country's future. The period likewise witnessed an unprecedented surge of political imagination, a development which is particularly visible in Interregnum utopianism. More than ever before, utopianism orientates itself to a hopeful and expectant reality. It is no longer fictional or contemplative. Its ambitions and fulfilment are political; there is a drive towards active political participation. Utopianism reshapes its former boundaries and reinvents itself as reality utopianism. Considering this new reality-orientated identity, the utopias of the 1650s are especially useful in providing an insight into the political imagination of this period. This thesis studies three reality utopias of the 1650s: Winstanley's The Law of Freedom, Harrington's Oceana and Hobbes's Leviathan. Each work represents a uniquely different utopian vision: Winstanley imagines an agrarian communism, Harrington revives classical republicanism, and Hobbes stresses absolute sovereignty. These three different utopian visions not only illustrate the range of the political imagination; they provide an opportunity to examine different ways to deal with the existing political and social concerns of the Interregnum and different perspectives for ideal solutions. Interregnum utopianism is shaped by the expectations and violence of the English Revolution and accordingly it is characterised by the heightened hopes and fears of its time. Despite substantial differences in the three utopias, the elemental hopes and fears expressed in these works remain similar. The hope for change and a better future is negotiated textually with a fear of anarchy and violence. In the end a compromise between opportunity and security has to be found. It is this compromise that shapes the face of Interregnum utopianism and reflects a major aspect of the post-revolutionary political imagination in England.
7
Hayduk, Ulf Christoph. "Hopeful Politics: The Interregnum Utopias." University of Sydney. English, 2005. http://hdl.handle.net/2123/703.
Full textAbstract:
The period of English history between the second Civil War and the Restoration opened up seemingly unlimited possibilities for shaping the country�s future. The period likewise witnessed an unprecedented surge of political imagination, a development which is particularly visible in Interregnum utopianism. More than ever before, utopianism orientates itself to a hopeful and expectant reality. It is no longer fictional or contemplative. Its ambitions and fulfilment are political; there is a drive towards active political participation. Utopianism reshapes its former boundaries and reinvents itself as reality utopianism. Considering this new reality-orientated identity, the utopias of the 1650s are especially useful in providing an insight into the political imagination of this period. This thesis studies three reality utopias of the 1650s: Winstanley�s The Law of Freedom, Harrington�s Oceana and Hobbes�s Leviathan. Each work represents a uniquely different utopian vision: Winstanley imagines an agrarian communism, Harrington revives classical republicanism, and Hobbes stresses absolute sovereignty. These three different utopian visions not only illustrate the range of the political imagination; they provide an opportunity to examine different ways to deal with the existing political and social concerns of the Interregnum and different perspectives for ideal solutions. Interregnum utopianism is shaped by the expectations and violence of the English Revolution and accordingly it is characterised by the heightened hopes and fears of its time. Despite substantial differences in the three utopias, the elemental hopes and fears expressed in these works remain similar. The hope for change and a better future is negotiated textually with a fear of anarchy and violence. In the end a compromise between opportunity and security has to be found. It is this compromise that shapes the face of Interregnum utopianism and reflects a major aspect of the post-revolutionary political imagination in England.
8
Farneti, Riccardo. "Oceanic planetary waves in the coupled ocean-atmosphere system." Thesis, University of Southampton, 2005. https://eprints.soton.ac.uk/25139/.
Full textAbstract:
The propagation of planetary, or Rossby, waves is studied under the effects of different atmospheric couplings. First, analytical matchings are formulated in which a Rossby wave is coupled to different thermodynamical atmospheres, from a simple heat flux condition to the inclusion of an atmospheric energy balance model. The effects on the vertical structure and phase speed of the first modes are negligible. However, it is shown that for the latter case an unstable mode appears. This growing mode, of decadal period and growth rate, has no physical source of energy and therefore is a result of the oversimplified atmosphere employed. In fact, adding physics to the atmospheric model results in a gradual disappearance of the instability. The possibility of observing similar unphysical modes in climate studies, where oversimplified models are adopted, is raised. Next, a quasi-geostrophic coupled model is used in order to analyse the oceanic Rossby wave characteristics under the influence of a full atmosphere. The idealised eddy-resolving model consists of an ocean basin underneath a channel atmosphere, and different configurations for the oceanic component are used. The Rossby waves are observed to propagate faster than both the classical linear theory (unperturbed solution) and the phase speed estimates when the effect of the zonal mean flow is added (perturbed solution). Moreover, using statistical eigentechniques, a coupled Rossby wave is identified, bearing the characteristics of the coupled mode proposed by Goodman and Marshall (1999). It is argued that the atmospheric coupling is capable of adding an extra speed up to the wave; in fact, when the waves are simply forced, their propagation speed approaches the perturbed solution. The waves are observed to break into faster waves, as suggested by LaCasce and Pedlosky (2004), although their resistance to dissipation and instabilities processes is enhanced by the atmospheric coupling, which provides extra energy to the initial wave during its propagation. The development of a coupled Rossby wave is found to be possible in a basin of the dimensions of both the Pacific and the Atlantic ocean, and its characteristics and strength vary little when the tridimensional accuracy of the ocean is increased.
9
Golden, Charles Edward. "Investigation of oceanic spreading center hydrothermal processes using ocean bottom seismometers /." Diss., Connect to a 24 p. preview or request complete full text in PDF format. Access restricted to UC campuses, 2000. http://wwwlib.umi.com/cr/ucsd/fullcit?p3035910.
Full text
10
Brainerd, Keith. "Upper ocean turbulence, mixing, and stratification /." Thesis, Connect to this title online; UW restricted, 1995. http://hdl.handle.net/1773/11007.
Full text
11
Šimek, Bohuslav. "Vývoj konceptu strategie "Modrých oceánů"." Master's thesis, Vysoká škola ekonomická v Praze, 2013. http://www.nusl.cz/ntk/nusl-165092.
Full textAbstract:
The strategic concept of "blue oceans" is currently undoubtedly one of the most interesting and most often talked strategic concepts. The thesis is therefore deals with the development of this strategic concept at the time and on the basis of previous papers of the authors in which were introduced tools and frameworks that later became part of the blue ocean strategy concept. The thesis also deals with other publications that the idea of the concept uses in own frames or in some way continues to build upon it. Further a description of the whole strategic concept is presented with each of analytical framework and tool with emphasis on additional context and findings of the section on the recent development of the concept. A key part of the thesis is the application of the concept to the three services - Knihovnička.cz Prezi and the Steam and evavulation of these tools with emphasis to the conclusions that have been made in the recent development of the strategic concept of "blue oceans" and its application.
12
Font, i. Ferré Jordi. "La circulació general a la mar Catalana." Barcelona : Centre de Publicacions, Intercanvi Cientific i Extensio Universitaria, Universitat de Barcelona, 1986. http://catalog.hathitrust.org/api/volumes/oclc/32908084.html.
Full text
13
Mehouachi, Fares. "Nature of Oceanic Lithosphere across the Equatorial fracture Zones in the Atlantic Ocean." Thesis, Sorbonne Paris Cité, 2019. http://www.theses.fr/2019USPCC014.
Full textAbstract:
La frontière de séparation entre la lithosphère rigide et l'asthénosphère ductile est un concept fondamental dans la théorie de la tectonique des plaques. Néanmoins l'observation géophysique d'une telle frontière reste un sujet de débat malgré l'avancée importante des méthodes d'imagerie géophysiques. Les études tomographiques des ondes de surface montrent une transition progressive entre la lithosphère et l'asthénosphère associée à une zone de faible vitesse de cisaillement, alors que les images obtenues à l'aide des "fonctions récepteurs" montrent une frontière nette associée à une polarité négative typique d'une diminution de la vitesse des ondes sismiques. La nature et la profondeur de la frontière lithosphère-asthénosphère restent mal connues. Pour remédier à cette situation, le projet ILAB (Imaging the Lithosphere Asthenosphere Boundary) utilise la méthode de la réflexion sismique pour localiser et étudier l'évolution de la frontière lithosphère-asthénosphère dans la zone des fractures équatoriales : Chain, Romanche et St. Paul, dans l'océan Atlantique. Deux résultats majeurs sont reportés: D'abord dans la région de la fracture de St. Paul (200 km), un système de deux réflecteurs profonds définit potentiellement la transition entre la lithosphère et l'asthénosphère. Ensuite dans la région de la dorsale Atlantique (500 km) une réflexion continue et plus profonde que le croûte océanique pourrait correspondre à la base de la lithosphère. Les méthodes et les procédures qui ont abouti à ces résultats sont présentées dans cette thèse ainsi qu'une nouvelle perspective sur l'origine de la frontière qui sépare la lithosphère et l'asthénosphèreLAB channel has a low viscosity that would allow the mechanical decoupling between the lithosphere and the asthenosphere, yet the LAB would require a large amount of volatiles, mainly water, to preserve its sub-solidus melt content (1.4%). The total amount of water trapped inside the LAB channel is very large (>> 100 ppm), yet it is surprisingly age independent despite the depth and thickness variation which suggests that a horizontal flux of volatiles originating probably from the ridge is feeding the LAB with its water content that gets focused and preserved inside the thinning LAB channel. The LAB is also potentially imaged across the Mid Atlantic Ridge (MAR) area, near the Chain transform fault using a state of the art imaging method, named as the Offset Continuation Dip Move-Out (OC-DMO), developed specifically to handle dipping structure in low SNR (Signal to Noise Ratio) environments. Plate boundaries and particularly Transform Faults (TF) are a unique setting in which the three-dimensional temperature profile could greatly affect the depth and the location of the LAB. A relatively shallow single reflector is reported underneath the MAR which deepens on both sides of the Ridge within an age range from 0 to 6 Myr but seems to flatten in the area closest to the Chain TF at ~20 km depth from the sea-surface at an age ranging from 6 to 18 Myr. This flattening stops around the edge of the TF and a rapid increase of depth is observed from ~20 km at 18 Myr to ~45 km at 22 Myr. The flattening cannot be explained by the thermal effect induced by the TF, which suggests the presence of different mechanism at play and potentially a lithospheric age anomaly. This age anomaly hypothesis is further confirmed by the lack of seafloor subsidence in the same area where the flattening is occurring. The lithosphere around the MAR near the Chain TF cannot be considered as a normal oceanic lithosphere, yet seems to confirm the correlation between the depth variation of the upper bound of the LAB and the lithospheric age, already observed in the St. Paul area
14
Zhang, Yuan. "An observational study of atmosphere-ocean interactions in the northern oceans on interannual and interdecadal time-scale /." Thesis, Connect to this title online; UW restricted, 1996. http://hdl.handle.net/1773/10038.
Full text
15
Kay, David J. "Mixing processes in a highly stratified tidal flow /." Thesis, Connect to this title online; UW restricted, 1998. http://hdl.handle.net/1773/9639.
Full text
16
Yi, Dong Hoon. "Investigating group behavioral quantization of oceanic fish with Continental-shelf scale ocean-acoustic sensing." Thesis, Massachusetts Institute of Technology, 2018. http://hdl.handle.net/1721.1/115671.
Full textAbstract:
Thesis: Ph. D., Massachusetts Institute of Technology, Department of Mechanical Engineering, 2018.Cataloged from PDF version of thesis.
Includes bibliographical references (pages 177-194).
The recent fish population decline due to increased human presence has led to calls for predictive methods to help reverse or stabilize the situation. It has been difficult, however, to establish such methods primarily due to the technical obstacles in observing fish populations in natural habitats. Here we use acoustics to observe the ocean environment and study fish behavior during the critical spawning period over continental-shelf scales. Fish are known to be one of the main sources of strong natural returns in the continental-shelf environment, and so identified as a major source of clutter for wide-area undersea surveillance. The first continental-shelf scale acoustic measurements of Atlantic cod over thousands of square kilometers using towed source and receiver arrays were made by an international, multi-disciplinary team led by MIT researchers including myself in the historic Lofoten cod spawning ground in Norway during the peak spawning period in Winter 2014, where extensive but spatially discrete groups of spawning cod were successfully imaged. These initial instantaneous wide-area observations of cod aggregations suggest that these observed spawning groups have quantifiable properties that are linked to essential collective behavioral functions. We find that the mean group population per annual spawning season of Northeast Arctic cod over the entire spawning ground in Lofoten Norway is remarkably invariant across the available 30 years of line-transect survey data. The marked stability of the annual mean spawning group size in contrast to the large variations in total spawning population across years supports the interpretation of the expected spawning group size over the 30-year data set as the group behavioral quantum empirically expected for reliable spawning. Time series of the total Atlantic cod spawning population for major spawning regions across the North Atlantic show that once the total spawning population declined below a quantum, recovery to preindustrial levels did not occur in that region even after decades, which is an apparent consequence of large difference between the pre-industrial level and one quantum level. Quantized group behavior during spawning is also investigated for the Atlantic herring species. We find that the daily herring spawning group population is stable over the peak annual spawning period from wide-area acoustic measurements of spawning herring in the Gulf of Maine in Fall 2006. This supports the quantum concept that the mean spawning group population has evolved to a stable optimal size to fulfill the essential behavioral function of reliable spawning for Atlantic herring. As with cod, time series of the Atlantic herring spawning population for major spawning grounds across the North Atlantic show that when total spawning population declined below the empirically determined quantum level, return to pre-industrial levels required decades. Our findings show that to be sustained at pre-industrial levels the total spawning population must greatly exceed the mean spawning group size found at pre-industrial levels for any oceanic fish population we investigated, and likely many others. The migration of extensive social groups towards specific spawning grounds in vast and diverse ocean environments is an integral part of the regular spawning process of many oceanic fish species. Oceanic fish in such migrations typically seek locations with environmental parameters that maximize the probability of successful spawning and egg/larval survival. The 3D spatio-temporal dynamics of these behavioral processes are largely unknown due to technical difficulties in sensing the ocean environment over wide areas. Here we use ocean acoustic waveguide remote sensing (OAWRS) to instantaneously image immense herring groups over continental-shelf-scale areas at the Georges Bank spawning ground. Via multi-spectral OAWRS measurements, we capture a shift in swimbladder resonance peak correlated with the herring groups' up-slope spawning migration, enabling 3D spatial behavioral dynamics to be instantaneously inferred over thousands of square kilometers. We show that herring groups maintain near-bottom vertical distributions with negative buoyancy throughout the migration. We find a spatial correlation greater than 0.9 between the average herring group depth and corresponding seafloor depth for migratory paths along the bathymetric gradient. This is consistent with herring groups maintaining near-seafloor paths to both search for optimal spawning conditions and reduce the risk of predator attacks during the migration to shallower waters where near-surface predators are more dangerous. This analysis shows that multi-spectral resonance sensing with OAWRS can be used as an effective tool to instantaneously image and continuously monitor the behavioral dynamics of swimbladder-bearing fish group behavior in 3 spatial dimensions over continental-shelf scales. Recent research has found a high spatial and temporal correlation between certain baleen whale vocalizations and peak annual spawning processes of Atlantic herring in the Gulf of Maine. These vocalizations are apparently related to feeding activities of baleen whales with suggested functions that include communication, prey manipulation, and echolocation. Here the feasibility of the echolocation function is investigated. Physical limitations on the ability to detect large herring shoals and the seafloor by acoustic remote sensing are determined with ocean acoustic propagation, scattering, and statistical theories given baleen whale auditory parameters. Detection is found to be highly dependent on ambient noise conditions, herring shoal distributions, baleen whale time-frequency vocalization spectra, and geophysical parameters of the ocean waveguide. Detections of large herring shoals are found to be physically feasible in common Gulf of Maine herring spawning scenarios at up to 10 ± 6 km in range for humpback parameters and 1 ± 1 km for minke parameters but not for blue and fin parameters even at zero horizontal range. Detections of the seafloor are found to be feasible up to 2 ± 1 km for blue and humpback parameters and roughly 1 km for fin and minke parameters, suggesting that the whales share a common acoustic sensation of rudimentary features of the geophysical environment. No effect of anthropogenic sound on marine mammal vocalization behavior was found during our measurements. Some published statistical tests assessing the impact of anthropogenic sound on marine mammal behavior were found to have 98-100% false positive biases with no true positive confirmation, and so lack statistical significance.
by Dong Hoon Yi.
Ph. D.
17
Mavume, Alberto Francisco. "Tropical cyclones in the South-West Indian Ocean : intensity changes, oceanic interaction and impacts." Doctoral thesis, University of Cape Town, 2008. http://hdl.handle.net/11427/11314.
Full textAbstract:
Includes abstract.Includes bibliographical references (p. 229-253).
This study investigates the climatology, intensification and ocean atmosphere interaction in relation to the passage of tropical cyclones (TCs) in the South-West Indian Ocean (SWIO). A Climatology of TCs in the SWIO including landfall in the area of Mozambique and Madagascar was developed for the 1952-2007 and 1980-2007 periods.
18
Garrard, Samantha Laird. "The effect of ocean acidification on plant-animal interactions in a Posidonia oceanica meadow." Thesis, Open University, 2013. http://oro.open.ac.uk/54714/.
Full textAbstract:
Ocean acidification may be one of the greatest challenges facing 'Society over the next SO- 100 years. In the Mediterranean Sea, meadows of the seagrass Posidonia oceanica play a pivotal role in coastal systems, providing shelter and food for a highly diversified plant and animal community, and nursery for several commercial species of fish and bivalves. This thesis aims to provide a broad overview of the effect of acidification on P. oceanica, and its associated community, through observation of seagrass meadows associated with subtidal CO2 vents off the Castello Aragonese, Ischia, Italy. Control (mean pH 8.1) and acidified (mean pH 7.8) stations were situated in seagrass meadows on both the north and south side of the Castello Aragonese. Research was concentrated into three main objectives; to investigate the effect of acidification on 1) plant structure and function, 2) invertebrate community dynamics, and 3) macroherbivore grazing pressure. Results suggested that P. oceanica and its associated community should be robust to levels of acidification projected for the end of this century. Seagrass density, invertebrate abundance, and P. oceanica grazing pressure all increased in response to acidification. Although a slight decrease in invertebrate diversity was observed in 'acidified stations, species richness was maintained. Increased grazing by the fish Salpa salpa was most highly correlated to a decrease in epiphytic algal cover and C:N content of the leaves, and an increase seagrass density. Whilst fish may select leaves with low algal cover and C:N content, previous research suggests that increased shoot density is a response to high grazing pressure. The abundance of many groups of invertebrate taxa was positively correlated to shoot density, whilst decapods decreased during months of reduced canopy height, suggesting changes in P. Qceanica condition variables, in response to acidification, may lead to a cascade of indirect effects which have positive or negative influences on the abundance of the associated invertebrate community. One of the most striking findings of this thesis was the ability of calcifying species to persevere, and even flourish in acidified conditions. This may be due to the complex nature of the seagrass, and high levels of photosynthesis, leading to local maintenance of pH microclimates. Secondly, the high degree of pH variability that naturally occurs in these shallow water habitats may result in organisms that are be better equipped to withstand pH variation. This research suggests that highly productive, non-calcifying, biogenic habitats, such as seagrass beds, may provide a refuge from OA, and highlights the importance of their conservation.
19
Augusto, Fabio Lekecinskas. "An improvement on the gas transfer velocity model with application to scatterometer data." Universidade de São Paulo, 2015. http://www.teses.usp.br/teses/disponiveis/21/21135/tde-07102015-143819/.
Full textAbstract:
The increase of carbon dioxide in the atmosphere observed in recent decades is causing the acidification of the oceans besides the global warming. The amount of carbon dioxide that crosses the air-sea interface is not well known because this amount depends upon the partial pressure of carbon dioxide and the gas transfer velocity. The gas transfer velocity is a variable based on Fick\'s Law of Diffusion and is normally parametrized as a function of wind velocity at the height of 10 meters. However, the result of this parametrization have errors greater than 100%. Newer parametrization include the effects of temperature, friction velocity and the presence of surface waves. Based on the simplest model of air-sea gas transfer model, the stagnant film theory, this study developed a methodology to improve the knowledge of the relation between the gas transfer velocity and the mean square slope. This variable accounts for the mean curvature of the waves in the surface. The data used was gathered within the scope of the DOGEE project in 2007. In that, a drifting buoy measured several parameters relative to the waves and the gas transfer velocity. The results show that the mean square slope calculated with waves whose wavenumber is between 40 and 50 radians per meter has the lowest root mean square errors of the regression between the mean square slope and the gas transfer velocity. This result showed to be very consistent when applied to the QuikSCAT scatterometer data and compared to a recent published study.O aumento da concentração de dióxido de carbono na atmosfera observado nas últimas décadas é responsável por alterações climáticas e ambientais em escala global. Uma das consequências desse aumento da concentração de gás carbônico é o aquecimento global. Outra consequência é a acidificação dos oceanos. Isto ocorre devido ao dióxido de carbono atravessar a interface ar-mar e se dissolver no oceano. A quantidade de dióxido de carbono que atravessa a interface ar-mar é um dado não conhecido com precisão devido a esta quantidade depender de uma constante conhecida por velocidade de transferência do gás carbônico. Esta velocidade de transferência é normalmente uma parametrização do transporte turbulento do gás na interface oceano-atmosfera. Como o dado mais comum para essa parametrização é o vento à altura de 10 metros, muitos estudos foram desenvolvidos utilizando esta variável. No entanto, os resultados destas parametrizações possuem erros da ordem de 100%. Este estudo desenvolveu uma metodologia para obter uma melhor estimativa da velocidade de transferência. Para isto, optou-se por relacionar esta variável à inclinação quadrática média (MSS) das ondas. Segundo a literatura científica recente, o MSS é uma variável mais relacionada à transferência gasosa do que o vento a 10 metros de altura. Os resultados mostram que a inclinação quadrática média calculado com números de onda entre 40 e 50 radianos por metro possuem o menor erro no ajuste linear com os dados de velocidade de transferência. Este resultado indica uma mudança da dinâmica da interface nesse intervalo de número de onda. Com isso, um novo ajuste linear entre o MSS e a velocidade de transferência é sugerido como parametrização. A aplicação desta nova parametrização a dados de satélite do tipo escaterômetro mostrou-se consistente quando comparado a um estudo recente relacionando a velocidade de transferência do gás carbônico diretamente a dados do satélite oceanográfico QuikSCAT.
20
Ryan, Andrea Catherine 1968. "Should we fertilize the oceans? : examining the science, economics and policy of the iron hypothesis & ocean fertilization." Thesis, Massachusetts Institute of Technology, 1998. http://hdl.handle.net/1721.1/9604.
Full textAbstract:
Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Civil and Environmental Engineering; and, (S.M.)--Massachusetts Institute of Technology, Technology and Policy Program, 1998.Includes bibliographical references.
John Martin's 'iron hypothesis' (Martin, 1990), and the subsequent ground-breaking IRONEX experiments (Martin 1994, Coale 1996) have stimulated wide spread speculation about the concept of fertilizing the oceans. It has been suggested that adding nutrients to the open oceans will stimulate primary production, increasing the sequestration of carbon dioxide and enhancing potential fish harvest. Ocean fertilization has thus been heralded as a possible cure for global climate change and world food shortages. Despite considerable scientific effort, private investment, and public interest in this field there has been limited evaluation of the feasibility of ocean fertilization. This thesis attempts to fill this void by addressing not only the scientific, but also the economic and policy dimensions of ocean fertilization. It starts by reviewing current research proposals and implementation activities in the field of ocean fertilization. It identifies potential environmental impacts and biogeochemical consequences of ocean fertilization, highlighting the outstanding scientific unknowns associated with this field. The study reviews cost estimates compiled by the private sector, and examines likely practical obstacles to implementation. Legal, political and public response to fertilization proposals is also explored. Finally, some of the ethical concerns relating to fertilizing the oceans are discussed, and recommendations on future research directions and initiatives to manage this rapidly growing field are provided.
by Andrea Catherine Ryan.
S.M.
21
Johnson, Clare. "Tracing Wyville Thomson Ridge overflow water in the Rockall Trough." Thesis, University of the Highlands and Islands, 2012. https://pure.uhi.ac.uk/portal/en/studentthesis/tracing-wyville-thomson-ridge-overflow-water-in-the-rockall-trough(07bd114b-bbec-4efe-9a13-783ba80ff83d).html.
Full textAbstract:
Although it has long been known that cold dense waters from the Nordic Seas overflow the Wyville Thomson Ridge, the water masses' subsequent pathways and fate have been uncertain. This study conclusively places Wyville Thomson Ridge Overflow Water (WTOW) as an important water mass in the eastern subpolar North Atlantic for the first time. Using a variety of chemical tracer s (chlorofluorocarbons, oxygen, nutrients and aluminium) in conjunction with temperature and salinity, WTOW is traced southwards into the northern and central Rockall Trough as well as into the channels between the western banks. The overflow water has a clear temperature, salinity and chlorofluorocarbon (CFC-11 and CFC-12) signature. Additionally, levels of aluminium are elevated in WTOW suggesting that this element is potentially a useful and novel water mass tracer. The lower oxygen layer complicates the use of dissolved oxygen and nitrate as tracers in the mid water column. However, higher and lower concentrations respectively in the western trough reveal the presence of WTOW in this area. The overflow water does not appear to have a silicate or phosphate signature. Two branches of WTOW exist in the Rockall Trough: a slow-moving indistinct intermediate branch (600-1200 m) f ound in both the east and west of the basin; and a coherent deep branch (> 1200 m) that flows southward along the western banks of the trough. As well as having a large spatial footprint within the Rockall Trough, intermediate a nd deep WTOW are temporally persistent being present 65-75 % of the time between 1975 and 2008. The signature of WTOW at intermediate depths is absent from the Ellett Line record in the mid-1980s and early-1990s. As deep WTOW is still observed during these periods flow over the Wyville Thomson Ridge cannot have ceased. Instead, it is proposed that the strength of the Subpolar Gyre is an important driver in the temporal distribution of intermediate WTOW within the Rockall Trough. When the gyre is strong, such as in the mid-1980s and early-1990s, the mid water column is dominated by waters originating from the west which block the southward flow of intermediate WTOW. In contrast, when the gyre is weak, such as in the late-1990s and 2000s, subpolar waters lie further west enabling intermediate waters within the Rockall Trough to be dominated by the southern orig inating Mediterranean Overflow Water and the northern water mass of WTOW.
22
Matthysen, Craig Peter. "Detail of the thermal structure of oceanic fronts in the Southern ocean south of Africa." Master's thesis, Faculty of Science, 1997. https://hdl.handle.net/11427/31853.
Full textAbstract:
This investigation addresses the thermal characteristics of the major oceanic frontal systems in the Southern Ocean south of Africa based on data collected to a depth of 500 m on forty-three cruises during a fifteen year period. The width of the Agulhas Front has been shown to vary considerably in both its sea surface and sub-surface thermal manifestation as a result of mesoscale turbulence. Its mean sea surface width of 84 km has a standard deviation of 53 km, and the mean subsurface width of 37 km has a standard deviation of 33 km. The Agulhas Front. has been found to be a separate front north of the Subtropical Convergence in 56 % of the cruises investigated. It has only been observed from 18,2°E to 24,7°E, with a mean sea and subsurface temperature gradient across the Agulhas Front of 0,05 °C/km and 0, 13 °C/km respectively. It has a mean sea surface middle temperature of 17, 8° C and a mean subsurface middle temperature of 12,6° C. The mean sea and sub-surface geographic positions of the thermal expression of the Agulhas Front are 39,3° S; 22,7° E aild 39,1° S; 22,7° E. The Subtropical Convergence at surface has been found to be a single, broad frontal zone across the Central/South East Atlantic Ocean, that does not bifurcate. It has a mean sea surface middle temperature of ·14,3° C and a mean sub-surface middle temperature of 8,4° C. The mean sea and sub-surface temperature gradients across the Subtropical Convergence are O, 03 °C/km and O, 05 °C/km respectively. The mean sea and sub-surface geographic positions of the· thermal expression of the Subtropical Convergence are 41, 8° S; 21, 9° E and 41, 7° S; 22, 0° E. The Subtropical Convergence has a mean sea surface width of 146 km and a mean sub-surface width of 79 km. The Sub-antarctic Front is pressed northward from 45° S to 43° S by the Mid-Ocean Ridge in the South West Indian Ocean sector, after which it converges · with the Subtropical Convergence at approximately 60° E to form a united STC/SAF at subsurface. This united STC/SAF does not however form a "Crozet Front" by joining the Agulhas Front between 52° E and 65° E. It has a mean sea surface middle temperature of 4,4° C and a mean sub-surface middle temperature of 4,0° C. The mean sea and subsurface temperature gradients across the Sub-antarctic Front are 0,02 °C/km. The mean sea and sub-surface geographic positions of the thermal expression of the Sub-antarctic Front are 48,7° S; 18,9° E and 46,8° S; 19,9° E. The Sub-antarctic Front has a mean sea surface width of 73 km and a mean sub-surface width of 77 km. In 30 % of the sections investigated the- Antarctic Polar Front consisted of a primary and secondary front. The Antarctic Polar Front does not join the Sub-antarctic Front east of · 40° E at sub-surface and subsequently no quadruple front is formed. It has a mean sea surface middle temperature of 2, 1 ° C and a mean sub-surface middle temperature of 2,3° C. The mean sea and sub-surface temperature gradients across the Antarctic Polar Front are 0,01 °C/km and 0,02 °C/km respectively. The mean sea and sub-surface geographic position of the thermal expression of the Antarctic Polar Front are 52, 7° S; 14,9° E and 49,2° S; 20,8° E. The Antarctic Polar Front has a mean sea surface width of 66 km and a mean sub-surface width of 74 km.
23
Mansour, Karam Abdelaal <1988>. "Ocean-Atmosphere Interactions: Linking Oceanic Biological Activity to Marine Aerosol Physico-Chemical and Cloud Properties." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2021. http://amsdottorato.unibo.it/9548/1/PhD_Thesis_UNIBO_Karam_Mansour.pdf.
Full textAbstract:
In this work, in-situ measurements of aerosol chemical composition, particle number size distribution, cloud-relevant properties and ground-based cloud observations were combined with high-resolution satellite sea surface chlorophyll-a concentration and air mass back-trajectory data to investigate the impact of the marine biota on aerosol physico-chemical and cloud properties. Studies were performed over the North-Eastern Atlantic Ocean, the central Mediterranean Sea, and the Arctic Ocean, by deploying both multi-year datasets and short-time scale observations. All the data were chosen to be representative of the marine atmosphere, reducing to a minimum any anthropogenic input. A relationship between the patterns of marine biological activity and the time evolution of marine aerosol properties was observed, under a variety of aspects, from chemical composition to number concentration and size distribution, up to the most cloud‐relevant properties. At short-time scales (1-2 months), the aerosol properties tend to respond to biological activity variations with a delay of about one to three weeks. This delay should be considered in model applications that make use of Chlorophyll-a to predict marine aerosol properties at high temporal resolution. The impact of oceanic biological activity on the microphysical properties of marine stratiform clouds is also evidenced by our analysis, over the Eastern North Atlantic Ocean. Such clouds tend to have a higher number of smaller cloud droplets in periods of high biological activity with respect to quiescent periods. This confirms the possibility of feedback interactions within the biota-aerosol-cloud climate system. Achieving a better characterization of the time and space relationships linking oceanic biological activity to marine aerosol composition and properties may significantly impact our future capability of predicting the chemical composition of the marine atmosphere, potentially contributing to reducing the uncertainty of future climate predictions, through a better understanding of the natural climate system.
24
Lacroix, Fabrice. "Riverine and coastal ocean contributions to the global and regional oceanic cycling of carbon and nutrients." Doctoral thesis, Universite Libre de Bruxelles, 2019. https://dipot.ulb.ac.be/dspace/bitstream/2013/289460/3/main.pdf.
Full textAbstract:
Les rivières sont une source importante de constituants biogéochimiques pour les océans. Jusqu’à présent, les modèles océaniques globaux représentaient de manière inadéquate ou ignoraient simplement les apports continentaux de nutriments, de carbone, d’alcalinité provenant des rivières. En particulier, les perturbations anthropiques des apports fluviaux au cours du 20 ème siècle et leurs conséquences sur l’état physique et biogéochimique des océans - notamment la zone côtière - n’ont pas encore été analysées à l’aide d’un modèle global prenant en compte la circulation tridimensionnelle de l’océan. L’objectif principal de cette thèse était donc d’intégrer les apports biogéochimiques provenant des rivières dans un modèle océanique global afin d’améliorer la compréhension du cycle du carbone de l’océan côtier et son évolution au cours du 20 ème siècle. Dans un premier temps, mon travail a visé à l’amélioration des connaissances concernant le rôle des apports biogéochimiques fluviaux sur le cycle du carbone océanique à long-terme, en se focalisant sur la période préindustrielle. Pour cela, j’ai estimé les apports des rivières en utilisant des modèles permettant d’estimer l’érosion chimique et le transfert de matière organique desécosystèmes terrestres à l’océan. Ces apports fluviaux ont ensuite été ajoutés dans le modèle biogéochimique océanique HAMOCC et leurs impacts sur la production primaire océanique et les flux de CO2 entre l’atmosphère et l’océan ont été analysés. Les résultats nous ont permis de quantifier un dégazage de CO 2 préindustriel de 0.23 Pg C yr -1 pour l’océan global, principalement localisé à proximité de l’embouchure des rivières. Le modèle a également démontré l’existence d’un transfert inter-hémisphèrique de carbone, avec un plus grand apport des rivières à l’océan dans l’hémisphère nord, et un transfert de l’hémisphère nord à l’hémisphère sud où un dégazage net se produit. Une augmentation considérable de la production primaire océanique induite par les apports des rivières a également été prédite.La modélisation biogéochimique de l’océan côtier a ensuite été améliorée, en augmentant la vitesse de minéralisation de la matière organique dans les sédiments côtiers et en incluant la dégradation de la matière organique dissoute d’origine terrestre (tDOM) dans l’océan. Par ailleurs, notre analyse suggère un temps de résidence des eaux dans la zone côtière significativement plus courte (14-16 mois en moyenne) que celui estimé jusqu’à présent (>4 ans). Ce temps de courte résidence implique un transfert efficace de matière organiquede l’océan côtier à l’océan ouvert, un état autotrophe net de l’océan côtier, ainsi qu’un puit de CO 2 (0.06-0.08 Pg C yr -1) pour la période préindustrielle, contrairement aux hypothèses précédemment proposées dans la littérature.Dans le dernier chapitre, les perturbations océaniques induites par les changements de la concentration en CO 2 dans l’atmosphère, de la physique de l’océan et des apports biogéochimiques fluviaux au cours du 20 ème siècle ont été analysées. Les résultats indiquent que la réduction de production primaire nette (NPP) observée dans les océans tropicaux et subtropicaux, pourrait être entièrement compensée par une augmentation de la NPP dans l’océan austral et dans les systèmes côtiers de type «EBUS». Les simulations montrent aussi que l’augmentation des apports fluviaux provoque une augmentation de NPP océanique à l’échelle de l’océan côtier (+15 %) et à l’échelle globale (+ 4 %). En conclusion, cette thèse a permis de démontrer l’importance d’inclure la variabilité spatio-temporelle des apports fluviaux et des processus biogéochimiques de l’océan côtier dans la description du cycle du carbone océanique global. Les améliorations apportées au modèle océanique global HAMOCC permettront d’affiner les prédictions du rôle de l’océan dans le cycle du carbone au cours du 21 ème siècle.River deliver vast amounts of terrestrially derived compounds to the ocean. These fluxes are of particular importance for the coastal ocean, which is recognized as a region of disproportionate contribution to global oceanic biological fluxes. Until now, the riverine carbon, nutrient and alkalinity inputs have been poorly represented or omitted in global ocean biogeochemistry models. In particular, there has yet to be a model that considers the pre-industrial riverine loads of biogeochemical compounds to the ocean, and terrestrial inputs of organic matter are greatly simplified in their composition and reactivities in the ocean. Furthermore, the coastal ocean and its contribution to the globalcarbon cycle have remained enigmatic, with little attention being paid to this area of high biological productivity in global model analysis of carbon fluxes. Lastly, 20 th century perturbations in riverine fluxes as well as of the physical and biogeochemical states of the coastal ocean have remained unexplored in a 3-dimensional model. Thus, the main goals of this thesis are to integrate an improved representation of riverine supplies in a global ocean model, as well as to improve the representation of the coastal ocean in the model, in order to solve open questions with respect its global contributions to carbon cycling.In this thesis, I first aimed to close gaps of knowledge in the long-term implications of pre-industrial riverine loads for the oceanic cycling of carbon in a novel framework. I estimated pre-industrial biogeochemical riverine loads and their spatial distributions derived from Earth System Model variables while using a hierarchy of state-of-the-art weathering and organic matter land-ocean export models. I incorporated these loads into the global ocean biogeochemical model HAMOCC and investigated the induced changes in oceanic biological production and in the air-sea carbon flux, both at the global scale and in a regional shelf analysis. Finally, I summarized the results by assessing the net land sink of atmospheric carbon prescribed by the terrestrial models, and comparing it to the long-term carbon outgassing determined in the ocean model. The study reveals a pre-industrial oceanic outgassing flux of 231 Tg C yr -1 ,which is found to a large degree in proximity to the river mouths. The model also indicates an interhemispheric transfer of carbon from dominant northern hemisphere riverine inputs to outgassing in the southern hemisphere. Furthermore, I observe substantial riverine-induced increases in biological productivity in the tropical West Atlantic (+166 %), the Bay of Bengal (+377 %) and in the East China Sea (+71 %), in comparison to a model simulation which does not consider the riverine inputs.In addition to considering supplies provided by riverine fluxes, the biogeochemical representation of the coastal ocean is improved in HAMOCC, by firstly increasing organic matter remineralization rates in the coastal sediment and by secondly explicitly representing the breakdown process of terrestrial dissolved organic matter (tDOM) in the ocean. In an analysis of the coastal fluxes, the model shows a much shorter residence time of coastal waters (14-16 months) than previously assumed, which leads to an efficient cross-shelf transport of organic matter and a net autotrophic state for both the pre-industrial timeframe and the present day. The coastal ocean is also revealed as a CO2 sink for the pre-industrial time period (0.06-0.08 Pg C yr -1 ) in contrary to to the suggested source in published literature. The sink is however not only caused by the autotrophic state of the coastal ocean, but it is likely also strongly influenced by the effects of biological alkalinity production, as well as both physical and biogeochemical characteristics of open ocean inflows.In the final chapter, 20 th century oceanic perturbations due to changes in atmospheric CO 2 concentrations and in the physical climate, and to increases in riverine nutrient supplies were investigated by using sequential model simulations. The model results show that the decrease in the net primary production (NPP) in the tropical and subtropical oceans due to temperature-induced stratification may be completely compensated by increases in the Southern Ocean and in Eastern Boundary Upwelling Systems (EBUS). The model also reveals that including increases in riverine supplies causes a global ocean NPP increase of +4 %, with the coastal ocean being a particularlystrongly affected region (+15 %).This thesis shows a strong necessity to represent spatio-temporal changes in riverine supplies and of the coastal ocean state in spatially explicit global models in order to assess changes of the global cycling of carbon in the ocean in the past and potentially in the future.
Doctorat en Sciences
info:eu-repo/semantics/nonPublished
25
Roos, Lundström Frida, and Anna Mårtensson. "The Journey of Plastic trough Oceans : A study on quantifying micro plastic particles in ocean outside Costa Rican west coast." Thesis, Högskolan i Halmstad, Akademin för ekonomi, teknik och naturvetenskap, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:hh:diva-28822.
Full textAbstract:
Since 1950, the plastic production has increased radically from 1.5 to 280 million tons in 2012. The increased production of plastic has led to oceans becoming more polluted than ever. Micro plastic particles originate from large floating plastic debris by undergoing degradation caused by UV-radiation. Due to their small size, density and colour micro plastic particles resemble marine organisms’ natural prey and are therefore ingested. This report discuss the hypotheses that there are micro plastic particles present in oceans outside of the Costa Rican west coast (hypothesis 1), that the location between the South and North Pacific gyres will result in an accumulation of plastic (hypothesis 2) and that different sampling methods will generate different types of data which makes it difficult to compare results (hypothesis 3). A manta trawl was used to collect samples in size range 1-2mm and they were quantified with a microscope. To simplifying transportation and storing, aluminum foil was used instead of glass jars to collect samples. Thereby the need of transferring material from a glass jar to a flat surface for quantifying with microscope was eliminated. One area contained 56.5 % of all gathered particles together. The result also showed that micro plastic particles are present even in protected areas.
26
Chadwick, David Bartholomew. "Tidal exchange at the bay-ocean boundary /." Diss., Connect to a 24 p. preview or request complete full text in PDF format. Access restricted to UC campuses, 1997. http://wwwlib.umi.com/cr/ucsd/fullcit?p9823709.
Full text
27
Hamme, Roberta Claire. "Applications of neon, nitrogen, argon, and oxygen to physical, chemical, and biological cycles in the ocean /." Thesis, Connect to this title online; UW restricted, 2003. http://hdl.handle.net/1773/10997.
Full text
28
Peres, Francielli Vilela. "Diversidade e conectividade de comunidades bacterianas em substratos sintéticos e orgânicos no atlântico sudoeste profundo." Universidade de São Paulo, 2016. http://www.teses.usp.br/teses/disponiveis/42/42132/tde-19012017-115607/.
Full textAbstract:
Organismos de mar profundo encontram limitações na disponibilidade de alimentos e exploram enriquecimentos orgânicos esporádicos que chegam ao assoalho oceânico. O objetivo deste trabalho foi descrever a diversidade das comunidades bacterianas associadas a parcelas sintéticas e orgânicas (vértebras de baleia e blocos de madeira) no Espírito Santo, Rio de Janeiro e São Paulo a 3.300 m de profundidade, avaliando a influência dos substratos e da localização geográfica sobre essas comunidades. Foi realizada a extração de DNA e amplificação do gene RNAr 16S para sequenciamento por Illumina Miseq e análises estatísticas pelo Qiime. Os Gêneros dominantes nos substratos sintéticos, madeira e vértebras foram Psychroserpens (Flavobacteriia), Phaeobacter, (Alphaproteobacteria), Desulfobacter, (Deltaproteobacteria), respectivamente. Com base nos resultados obtidos, afirma-se que o tipo de substrato teve maior influência do que a localização geográfica sobre a estrutura das comunidades bacterianas.Deep sea organisms found limitations in the availability of food and exploit sporadic organic enrichments that reach the ocean floor. The aim of this study was to describe the diversity of bacterial communities associated with synthetic and organic substrate (whale bone and wood blocks) in Espírito Santo, Rio de Janeiro and Sao Paulo to 3,300 m deep, assessing the influence of substrates and location geographical about these communities. 16S rRNA sequencing was performed by Illumina Miseq and statistical analysis by Qiime. The dominant genera in synthetic substrates, wood and vertebrae were Psychroserpens (Flavobacteriia), Phaeobacter (Alphaproteobacteria) and Desulfobacter, (Deltaproteobacteria), respectively. Based on these results, it is stated that the substrate type had greater influence than geographic location on the structure of bacterial communities.
29
Goddard, Paul Brent, and Paul Brent Goddard. "Oceanic Controls of North American East Coast Sea Level Rise and Ocean Warming of the Antarctic Shelf." Diss., The University of Arizona, 2018. http://hdl.handle.net/10150/626684.
Full textAbstract:
Sea level rise (SLR) threatens coastal communities, infrastructure, and ecosystems. Worldwide, stakeholders critically depend on SLR projections with the associated uncertainty for risk assessments, decision-making and coastal planning. Recent research suggests that the Antarctic ice sheet mass loss during the 21st century may contribute up to an additional one meter of global SLR by year 2100. While uncertainty still exists, this value would double the ‘likely’ (> 66% probability) range of global SLR (0.52-0.98 m) by the year 2100, as found by Chapter 13 on Sea Level Change in the Fifth Assessment Report by the Intergovernmental Panel on Climate Change. Here, we present three studies that assess mechanisms relevant to 21st century local, regional, and global SLR. Appendix A examines the effect of large-scale oceanic and atmospheric circulation variability on extreme sea levels along the East Coast of North America. Appendices B and C analyze ocean warming on the Antarctic shelf and its implications for future ice shelf basal melt and Antarctic Ice Sheet mass loss. These studies will contribute to more accurate projections of local, regional, and global SLR.
In Appendix A, we analyze long-term tide gauge records from the North American eastern seaboard and find an extreme SLR event during 2009-2010. Within this two-year period, coastal sea levels spiked between Montauk, New York and Southern Canada by up to 128 mm. This two-year spike is unprecedented in the tide gauge record and found to be a 1-in-850 year event. We show that a 30% reduction in strength of the Atlantic meridional overturning circulation (AMOC) and a strong negative North Atlantic Oscillation (NAO) index caused the extreme SLR event. Climate models project that the AMOC will weaken and NAO variability will remain high over the 21st century. Consequently, extreme SLR events on the Northeast Coast could become more frequent during the 21st century in response to climate change and SLR.
In Appendix B, we use a fine-resolution global climate model (GFDL CM2.6) that resolves an eddying ocean. With this state-of-the-art coupled model, we quantify the mechanisms contributing to ocean warming on the Antarctic continental shelf in an idealized experiment of doubling of the atmospheric CO2 concentration. The results show that the CO2 forcing leads to the shelf region warming both in the upper 100 m ocean and at depths near the sea floor. These warming patterns are controlled by different mechanisms. In the upper 100 m, the heat anomalies are primarily controlled by increased heat transport into the shelf region associated with the warmer near-surface waters from lower latitudes. Below 100 m, the heat anomalies develop due to increased onshore intrusions of relatively warm Circumpolar Deep Water and reduced vertical mixing of heat in the water column. A complete heat budget analysis is performed for the Antarctic shelf region as well as for six subdomains and three depth ranges (0-100 m, 100-700 m, and 700-1000 m). The results show that certain regions of the Antarctic shelf are more susceptible to large CO2-forced warming. These findings have implications for future Antarctic Ice Sheet mass loss and SLR, and can provide more detailed and accurate ocean boundary conditions for dynamical ice sheet models.
In Appendix C, we use CM2.6 to examine the connections among ocean freshening and the magnitude and location of ocean warming on the Antarctic shelf. We find that CO2 forcing freshens the Antarctic shelf seas via increases in local precipitation, sea ice loss, liquid runoff, and iceberg calving. The freshening induces three heat budget-relevant responses: (1) reduced vertical mixing; (2) strengthening of the Antarctic Slope Front (ASF); and (3) increased eddy kinetic energy (EKE) near the ASF. First, heat can accumulate at depth (100-1000 m) as freshening increases the vertical stratification on the shelf and reduces upward mixing of heat associated with diffusion and convective processes. Second, freshening near the shelf break strengthens the ASF by increasing the lateral density gradient and by steepening and deepening the associated isopycnals. This response limits cross-ASF onshore heat transport at many locations around Antarctica. Third, EKE increases near the ASF may contribute to shelf warming by increasing cross-ASF onshore eddy heat transport. These results demonstrate the importance of shelf freshening to the development of positive heat anomalies on the Antarctic shelf. The findings provide new insight to the location of future shelf warming and ice shelf basal melting as well as provide significant information for projecting regional and global SLR.
30
Williams, Clare Margaret. "Oceanic lithosphere magnetization marine magnetic investigations of crustal accretion and tectonic processes in mid-ocean ridge environments /." Thesis, Massachusetts Institute of Technology, 2007. http://hdl.handle.net/1912/2031.
Full textAbstract:
Thesis (Ph. D.)--Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 2007."Joint Program in Oceanography/Applied Ocean Science and Engineering"--Cover. Title from Web page (viewed on Mar. 24, 2008). "September 2007". Includes bibliographical references.
31
Crum, Emily J. "A Scientific Communication Internship with the National Oceanic and Atmospheric Administration, National Ocean Service, Special Projects Office." Miami University / OhioLINK, 2006. http://rave.ohiolink.edu/etdc/view?acc_num=miami1142869128.
Full text
32
Arsego, Diogo Alessandro. "FLUXOS DE CALOR E TRANSFERÊNCIA DE ENERGIA CALORÍFICA ENTRE O OCEANO E A ATMOSFERA SOBRE ESTRUTURAS OCEÂNICAS DE MESOESCALA NO ATLÂNTICO SUL." Universidade Federal de Santa Maria, 2012. http://repositorio.ufsm.br/handle/1/10263.
Full textAbstract:
Understanding the interactions between ocean and atmosphere in regions of oceanographic
fronts is of vital importance for the improvement of numerical models for weather and climate
forecasting. In the South Atlantic Ocean (SAO) the meeting between the warm waters of the Brazil
Current (BC) and the cold waters of the Malvinas (Falkland) Current (MC) in the region known as the
Brazil-Malvinas Confluence (BMC), results in intense mesoscale oceanic activity and, for this reason,
this region is considered one of the most energetic of the Global Ocean. The interactions resulting
from the thermal contrast in regions oceanographic fronts of the OAS are investigated in this work
through estimates of heat fluxes based on data collected in situ and by satellite. The results of this
study show that the response to the thermal contrasts found in the ocean is in the form of heat fluxes
and these fluxes are critical in modulating the atmospheric boundary layer (ABL). Estimation based on
data collected in situ show that in the warm side (north) of the oceanographic front the fluxes are more
intense (latent heat: 62 W/m² and sensible heat: 0.6 W/m²) than in the cold side (south) (latent heat:
5.8 W/m² and sensible heat: -13.8 W/m²). In the South Atlantic Current (SAC) along the 30° S
parallel, heat fluxes are directly related to the meandering characteristic of the current. The data
collected in situ, in addition to allow heat flux estimates at a better spatial resolution, were used to
develop a new method for estimating the heat energy exchanged between the atmosphere and the
ocean caused by the presence of mesoscale oceanic structures. This methodology consists in the
comparison of a radiosonde profile taken over waters of the structure of interest and another taken
over waters which do not belong to this structure. The methodology was used to estimate the heat
energy transfer between the atmosphere and the ocean over the top of three structures sampled in the
OAS. The estimation of the heat energy transferred by a warm eddy detached from the BC points to an
energy in the latent (sensible) form of 1.6 1017 J (-2.8 1016 J) which corresponds to approximately
0.011 % of the total heat energy of the eddy transferred to the atmosphere during the field experiment
and 0.78 % transferred during the supposed lifetime of the eddy (3 months). Along the CSA two
oceanic structures were studied: (i) a cold meander that receives from the atmosphere energy in the
latent (sensible) form of 1.4 106 J/m2 (5.4 105 J/m2), and (ii) warmer waters associated with a
detached eddy from the Agulhas Current (AC) that transfer to the atmosphe heat energy of
approximately 4 106 J/m2 an 5.7 106 J/m2 in the latent and sensible forms, respectively. The
estimation of heat energy transfer on top of mesoscale oceanic structures clearly demonstrate the
importance of these structures for the heat exchanges between the ocean and the atmosphere and must
be taken into account in future works about this subject in the SAO.A compreensão das interações entre oceano e atmosfera em regiões de frentes oceanográficas é de vital importância para o melhoramento de modelos numéricos de previsão do tempo e clima. No Oceano Atlântico Sul (OAS) o encontro entre as águas quentes da Corrente do Brasil (CB) com as águas frias da Corrente das Malvinas (CM), na região denominada Confluência Brasil-Malvinas (CBM), resulta em intensa atividade oceânica de mesoescala e, por esse motivo, essa região é considerada uma das mais energéticas do Oceano Global. As interações resultantes do contraste termal ao longo de regiões de frentes oceanográficas no OAS são investigadas neste trabalho através de estimativas de fluxos de calor baseadas em dados de satélite e dados coletados in situ. Os resultados do trabalho demonstram que a resposta aos contrastes termais encontrados no oceano se dá na forma de fluxos de calor e que esses fluxos são fundamentais na modulação da Camada Limite Atmosférica (CLA). As estimativas com base em dados coletados in situ demonstram que no lado quente (norte) da frente oceanográfica os fluxos são mais intensos (calor latente: 62 W/m² e calor sensível: 0,6 W/m²) que nos lado frio (sul) (calor latente: 5,8 W/m² e calor sensível: -13,8 W/m²). Na Corrente Sul Atlântica (CSA), ao longo do paralelo de 30° S, os fluxos de calor estão diretamente relacionados a característica meandrante da corrente. Os dados coletados in situ, além de possibilitarem estimativas de fluxo de calor com uma melhor resolução espacial, foram usados no desenvolvimento de uma nova metodologia para estimativa da energia calorífica trocada entre oceano e atmosfera em virtude da presença de estruturas oceânicas de mesoescala. Essa metodologia consiste na comparação entre um perfil de radiossonda tomado sobre águas da estrutura de interesse e outro tomado sobre águas que não pertencem a essa estrutura. A metodologia desenvolvida foi utilizada para determinar a transferência de energia calorífica entre oceano e atmosfera em três estruturas amostradas no OAS. A estimativa da energia calorífica transferida por um vórtice quente desprendido da CB aponta para uma energia na forma latente (sensível) de 1,6 1017 J (-2,8 1016 J) que corresponde a aproximadamente 0,011 % da energia calorífica total do vórtice transferida durante o experimento de campo e de 0,78 % da energia do vórtice transferidos durante o tempo suposto de vida do vórtice (3 meses). Ao longo da CSA, duas estruturas oceânicas foram estudadas: (i) um meandro frio que recebe da atmosfera uma energia na forma latente (sensível) de 1,4 106 J/m2 (5,4 105 J/m2) e (ii) águas mais quentes associadas a um vórtice desprendido da Corrente das Agulhas (CA) que transferem para a atmosfera uma energia calorífica de aproximadamente 4 106 J/m2 e 5,7 106 J/m2 nas formas latente e sensível, respectivamente. As estimativas da transferência de energia calorífica sobre estruturas oceânicas de mesoescala demonstram claramente a importância destas nas trocas de calor entre o oceano e a atmosfera e devem ser levadas em consideração em trabalhos futuros sobre o tema no OAS.
33
Marques, Beatriz Andrade da Silva. "Avaliação do potencial de fertilização decorrente da deposição de cinzas vulcânicas do complexo andino Puyehue-Cordón Caulle em águas do Atlântico Sul/Oceano Austral." Niterói, 2016. https://app.uff.br/riuff/handle/1/1573.
Full textAbstract:
Submitted by Biblioteca de Pós-Graduação em Geoquímica BGQ (bgq@ndc.uff.br) on 2016-03-28T16:36:04Z
No. of bitstreams: 1
Dissertação - Beatriz Andrade da Silva Marques.pdf: 4181094 bytes, checksum: 0f82a71603a769606e160fbeabb2e770 (MD5)Made available in DSpace on 2016-03-28T16:36:04Z (GMT). No. of bitstreams: 1 Dissertação - Beatriz Andrade da Silva Marques.pdf: 4181094 bytes, checksum: 0f82a71603a769606e160fbeabb2e770 (MD5)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior
Universidade Federal Fluminense. Instituto de Química. Programa de Pós-Graduação em Geociências-Geoquímica. Niterói, RJ
O vulcanismo é um potencial agente fertilizador de via eólica para os oceanos. Para as últimas décadas, o sensoriamento remoto tem sido uma ferramenta importante no sentido de avaliar em tempo quase-real alterações de parâmetros nos oceanos durante os episódios de erupção vulcânica, em geral com alta resolução temporal e espacial. Evidências experimentais ainda são pouco reportadas, sobretudo para o hemisfério sul. Este trabalho investiga a resposta biológica decorrente do aporte das cinzas expelidas durante o evento eruptivo de 2011 do complexo vulcânico andino Puyehue-Cordón Caulle em águas do Atlântico Sul / Oceano Austral. Duas abordagens foram empregadas no estudo: (1) sensoriamento remoto orbital; e (2) experimento de fertilização em microcosmo. A investigação feita por meio de sensoriamento remoto utilizou os parâmetros satelitais Espessura Óptica de Aerossol (AOT), Concentração de Clorofila-a (CHL-a) e Temperatura da Superfície do Mar (SST), aquisitados pelo sensor MODIS/Aqua e acessados através do portal Ocean Color mantido pelo OBPG/NASA. O contexto pós-erupção foi avaliado comparando os valores dos parâmetros para o ano (2011) com o valor da série histórica criada com dados de 2002 à 2010. O bioensaio de fertilização foi realizado com as cinzas vulcânicas do evento eruptivo em questão, com tréplicas do controle e outros três tratamentos, distintos em massa de cinzas inserida, em águas coletadas no centro da Passagem de Drake. Os resultados obtidos a partir das duas abordagens deste trabalho, sensoriamento remoto e bioensaio, não são taxativos sobre o acoplamento entre a deposição das cinzas da erupção do complexo vulcânico Puyehue-Cordón Caulle e a possível ocorrência de um evento de fertilização oceânica. Através da análise por sensoriamento remoto é possível notar para o período de intensificação dos ventos de oeste do mesmo ano – primavera-verão – que há picos nas medidas de espessura óptica da atmosfera e de concentração de clorofila, que atingem valores maiores que a média histórica. Isto indica que houve aporte de material continental e que este foi suficiente para propiciar maior desenvolvimento algal no oceano. Estes resultados indicam que a poeira mineral, constituída por material de erosão continental com a contribuição dos depósitos de composições distintas de cinzas expelidas nas diversas erupções andinas, é capaz de prover micronutrientes escassos na coluna d’água ao fitoplâncton, com aumento de biomassa algal de uma comunidade fitoplanctônica não limitada por outros parâmetros (condições de irradiação suficiente, temperaturas menos baixas, camadas de mistura mais rasas e pressão de predação menos intensa). A hipótese também poderia esclarecer a falta de resultados conclusivos do bioensaio feito apenas com as cinzas, sem qualquer beneficiamento de outras fontes continentais
Volcanism is a potential agent for fertilizing by wind the oceans. In the last decades, remote sensing has been an important tool that allows evaluations of near-real-time changes in oceanographic parameters during episodes of volcanic eruptions, in general with high temporal and spatial resolution. Experimental evidences are still poorly reported, especially for the southern hemisphere. This work investigates the biological response resulting from the input of ash expelled during the 2011 eruptive event of the Andean volcanic complex Puyehue-Cordón Caulle over waters of the Atlantic Ocean / Southern Ocean. Two approaches were employed in the study: (1) remote sensing; and (2) fertilization experiment. The research carried out by means of remote sensing, used the satellite parameters Aerosol Optical Thickness (AOT), Concentration of Chlorophyll-a (CHL-a) and Sea Surface Temperature (SST), acquired by MODIS / Aqua and accessed through the Ocean Color portal maintained by OBPG / NASA. The context of post-eruption was assessed by comparing the values of the parameters for the year (2011) with the value of climatology created with data from 2002 to 2010. The fertilization bioassay was performed with volcanic ash from the considered eruption event, with rejoinders of four treatments, different in volume, in water collected in the Drake Passage. The results from the two approaches this work, remote sensing and bioassay, are not exhaustive of the coupling between the deposition of ash from the eruption of the Puyehue-Cordón volcanic complex Caulle and the possible occurrence of an ocean fertilization event. Through remote sensing analysis it is possible to note that, with the intensification period of westerly winds of the same year - spring and summer, there are peaks in aerosol optical thickness measurements of the atmosphere and in concentration of chlorophyll, which reach values higher than the historical average. This indicates that there has been input of continental material, and that this was sufficient to provide greater algal development in the ocean. These results indicate that the mineral dust, formed by continental erosion material with the contribution of deposits of different compositions of ash expelled in several Andean rash, is capable of providing scarce micronutrients in the water column to phytoplankton, with an increase of algal biomass in a phytoplankton community not limited by other parameters (sufficient irradiation conditions, less low temperatures, shallower mixing layers and less intense predation pressure). The hypothesis could also explain the lack of conclusive bioassay results done only with the ashes without any contribution of other continental sources
34
Xu, Min Ph D. Massachusetts Institute of Technology. "Advanced geophysical studies of accretion of oceanic lithosphere in Mid-Ocean Ridges characterized by contrasting tectono-magmatic settings." Thesis, Massachusetts Institute of Technology, 2012. http://hdl.handle.net/1721.1/70780.
Full textAbstract:
Thesis (Ph. D.)--Joint Program in Oceanography (Massachusetts Institute of Technology, Dept. of Earth, Atmospheric, and Planetary Sciences; and the Woods Hole Oceanographic Institution), 2012.Cataloged from PDF version of thesis.
Includes bibliographical references.
The structure of the oceanic lithosphere results from magmatic and extensional processes taking place at mid-ocean ridges (MORs). The temporal and spatial scales of the variability of these two processes control the degree of heterogeneity of the oceanic lithosphere, represented by two end-member models: the classical Penrose Model exemplified by layered magmatic crust formed along fast-spreading MORs, e.g., East Pacific Rise (EPR); and the recently defined Chapman Model describing heterogeneous mafic and ultramafic lithosphere formed in settings of oceanic detachment faulting common along slow-spreading MORs, e.g., Mid-Atlantic Ridge (MAR). This thesis is using advanced marine geophysical methods (including finite-difference wave propagation modeling, 3D multi-channel seismic reflection imaging, waveform inversion, streamer tomography, and near-bottom magnetics) to study lithospheric accretion processes in MORs characterized by contrasting tectono-magmatic settings: the magmatically dominated EPR axis between 9°30'-10°00°N, and the Kane Oceanic Core Complex (KOCC), a section of MAR lithosphere (23°20°-23°38°N) formed by detachment faulting. At the EPR study area, I found that the axial magma chamber (AMC) melt sill is segmented into four prominent 2-4-km-long sections spaced every -5- 10 km along the ridge axis characterized by high melt content (>95%). In contrast, within the intervening sections, the AMC sill has a lower melt content (41-46%). The total magma volume extracted from the AMC sill was estimated of ~46 x 106 M3, with ~24 x 106 M3 left unerupted in the upper crust as dikes after 2005-06 eruption. At the KOCC, I used streamer tomography to constrain the shallow seismic velocity structure. Lithological interpretation of the seismic tomographic models provides insights into the temporal and spatial evolution of the melt supply at the spreading axis as the KOCC formed and evolved. Investigation of a magnetic polarity reversal boundary in crosssection at the northern boundary of KOCC suggests that the boundary (representing both a frozen isotherm and an isochron) dips away from the ridge axis along the Kane transform fault scarp, with a west-dipping angle of ~45° in the shallow (<1 km) crust and <20° in the deeper crust.
by Min Xu.
Ph.D.
35
Johnson, Kevin Todd Michael. "Trace element geochemistry of oceanic peridotites and silicate melt inclusions--implications for mantle melting and ocean ridge magmagenesis." Thesis, Massachusetts Institute of Technology, 1990. http://hdl.handle.net/1721.1/54339.
Full textAbstract:
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Earth, Atmospheric, and Planetary Sciences, and Woods Hole Oceanographic Institution, 1990.Vita.
Includes bibliographic references.
by Kevin Todd Michael Johnson.
Ph.D.
36
Finotti, Elisângela. "PERFIL VERTICAL DA TEMPERATURA OCEÂNICA EM ANOS DE EVENTOS DO ENOS." Universidade Federal de Santa Maria, 2015. http://repositorio.ufsm.br/handle/1/10283.
Full textAbstract:
Coordenação de Aperfeiçoamento de Pessoal de Nível SuperiorIn the present work we studied the vertical profile of the Global Ocean temperature in years of occurrence El Nino-Southern Oscillation events, to better understand the functioning of this phenomenon. For its realization were used three sets of ocean reanalysis: ORAS4 produced by European Centre for Medium-range Weather Forecasts, the GODAS produced by National Centers for Environmental Prediction and SODA produced by Carton and Giese, 2008. The three sets of reanalysis showed the same potential temperature pattern in all layers of depth. The Ocean Temperature Index Equatorial Pacific is very well El Nino-Southern Oscillation events, as detected all El Niños and La Niñas occurred in the period of 52 years. Finally, it is concluded that the proposed new index can be used to determine (characterization) of El Nino-Southern Oscillation events with the same precision as the Oceanic Niño Index, and with superior accuracy for predicting El Nino-Southern Oscillation events as it detects these events several months in advance of the Oceanic Niño Index. Therefore, we can add one more tool to help us predict and better understand the El Nino-Southern Oscillation events.
No presente trabalho foi estudado o perfil vertical da temperatura do Oceano Global, em anos de ocorrência de eventos de El Niño Oscilação Sul, para compreender melhor o funcionamento deste fenômeno. Para a sua realização foram utilizados três conjuntos de reanálises oceânicas: ORAS4 produzida pelo European Centre for Medium-range Weather Forecasts, o GODAS foi desenvolvido pelo National Centers for Environmental Prediction e SODA desenvolvido por Carton e Giese, 2008. Os três conjuntos de reanálises apresentaram o mesmo padrão de temperatura potencial em todas as camadas de profundidade. O Índice de Temperatura Oceânica do Pacífico Equatorial representa muito bem os eventos de El Niño-Oscilação Sul, uma vez que detectou todos os EL Niños e La Niñas ocorridos no período de 52 anos. Por fim, conclui-se que o novo índice proposto pode ser utilizado para determinação (caracterização) de eventos de El Niño-Oscilação Sul com a mesma precisão que o Índice de Niño Oceânico, e com superior precisão para a previsão de eventos de El Niño-Oscilação Sul, uma vez que detecta estes eventos com alguns meses de antecedência em relação ao Índice de Niño Oceânico. Assim podemos acrescentar mais uma ferramenta que nos ajudará a prever e entender melhor os eventos de El Niño-Oscilação Sul.
37
Zheng, Xinyuan. "Oceanic cycling of rare earth elements and the application of Nd isotopes to assess changes in Mesozoic ocean circulation." Thesis, University of Oxford, 2016. http://ora.ox.ac.uk/objects/uuid:0b06129a-8f51-4421-a043-5eeb86cec972.
Full textAbstract:
Rare earth elements (REEs) and their isotopes (such as Nd isotopes) can be potentially used to trace a wide range of oceanic processes in both modern and ancient oceans, but their successful application as tracers requires a comprehensive understanding of REE cycling in the modern ocean. Previous studies of REEs in seawater were largely constrained by analytical difficulties in generating accurate and precise REE data from seawater, which typically contain REE concentrations at a sub-ppt to ppt level. A new, and relatively simple, analytical method for precise and accurate determination of all dissolved REE concentrations in reasonably small (∼100 ml) seawater samples is presented in this thesis. With the application of the new method, this thesis reports the first full-depth, zonal ocean section of all dissolved REE concentrations, collected during the CoFeMUG cruise along ∼12°S in the South Atlantic. The section approach of this study places the distribution of dissolved REE concentrations in a well-constrained hydrographic context, allowing the first quantitative assessment (by an inverse model) of the relative importance of hydrographic controls resulting from advection/mixing of ocean circulation, together with non-conservative controls resulting from local particle scavenging and remineralization, in controlling the distribution of dissolved REEs in this region. A noteworthy decoupling of Ce and Mn with respect to their cycling in the water column was also observed in this study. The application of Nd isotopes as a tracer to reconstruct changes in ocean circulation in the NW European chalk shelf sea during rapid climatic events, including the mid-Cenomanian Event and oceanic anoxic event 2 (OAE 2), suggests a tight coupling between ocean circulation and transient climatic cooling during the general warm Late Cretaceous. An advected volcanic signal during OAE 2 was registered in the seawater Nd-isotope record from the English Chalk, probably suggesting a period of enhanced ocean ventilation/mixing at this time.
38
au, debkennedy@iprimus com, and Deborah Jane Kennedy. "Ocean Views : An investigation into human-ocean relations." Murdoch University, 2007. http://wwwlib.murdoch.edu.au/adt/browse/view/adt-MU20080523.120432.
Full textAbstract:
This dissertation investigates some conceptions of oceans in modern Western societies that are highly influential in shaping human-ocean relations. My main aim in this dissertation is to demonstrate that the Western discourses of law, science and the aesthetic of the sublime illuminate characteristics of human-ocean relations in Western societies. I argue that the conceptions developed and perpetuated in the discourses of law, aesthetics and science unnecessarily constrain the possibilities for human-ocean relations and undermine just existences of oceans. A further aim of this dissertation is to set out an ethical political approach that is inclusive of a diversity of ocean views that facilitate improved knowledge about the oceans and transform dominant human ocean relations into more just relations.
In approaching my critique of Western discourses of law, aesthetics and science I canvas a range of philosophical, social and political theories, but make most use of the insights of feminist and ecological feminist thinkers into forms of oppression and environmental justice. I also move beyond critique to set out an approach for structuring ocean policy debates and outcomes with a form of political epistemology that de-centres influential Western conceptions of oceans and is inclusive of a diversity of perspectives.
In carrying out this dissertations investigation I find that particular conceptions of oceans in the discourses of law, aesthetics and science narrowly define how Western human subjects think, feel and interact with oceans. These discourses provide a dominant position for Western subjects over those of other people and the oceans. This is how, in basic terms, I suggest that Western discourses undermine just existences for oceans. A common feature in the discourses that frame the conceptions of oceans that I discuss is the exclusion of a diversity of human-ocean relations from consideration. To counter the exclusionary practices of Western discourses I find that robust democratic processes are essential for just ocean existences. The importance of democratic processes is not only that they constitute ethical processes, and should be valued highly for that reason, but also because of a capacity to produce and deliver improved knowledge about the oceans and transform human-ocean relations. I advocate in particular the approach to political epistemology of Bruno Latour as one way to work toward just ocean existences. In the approach I advocate, oceans participate in democratic processes as agents, not as mere objects awaiting human benevolence or exploitation.
39
Bos, Machiel Simon. "Ocean tide loading using improved ocean tide models." Thesis, University of Liverpool, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.343980.
Full text
40
Kennedy, Deborah Jane. "Ocean views: an investigation into human-ocean relations." Thesis, Kennedy, Deborah Jane (2007) Ocean views: an investigation into human-ocean relations. PhD thesis, Murdoch University, 2007. https://researchrepository.murdoch.edu.au/id/eprint/123/.
Full textAbstract:
This dissertation investigates some conceptions of oceans in modern Western societies that are highly influential in shaping human-ocean relations. My main aim in this dissertation is to demonstrate that the Western discourses of law, science and the aesthetic of the sublime illuminate characteristics of human-ocean relations in Western societies. I argue that the conceptions developed and perpetuated in the discourses of law, aesthetics and science unnecessarily constrain the possibilities for human-ocean relations and undermine just existences of oceans. A further aim of this dissertation is to set out an ethical political approach that is inclusive of a diversity of ocean views that facilitate improved knowledge about the oceans and transform dominant human ocean relations into more just relations.
In approaching my critique of Western discourses of law, aesthetics and science I canvas a range of philosophical, social and political theories, but make most use of the insights of feminist and ecological feminist thinkers into forms of oppression and environmental justice. I also move beyond critique to set out an approach for structuring ocean policy debates and outcomes with a form of political epistemology that de-centres influential Western conceptions of oceans and is inclusive of a diversity of perspectives.
In carrying out this dissertation's investigation I find that particular conceptions of oceans in the discourses of law, aesthetics and science narrowly define how Western human subjects think, feel and interact with oceans. These discourses provide a dominant position for Western subjects over those of other people and the oceans. This is how, in basic terms, I suggest that Western discourses undermine just existences for oceans. A common feature in the discourses that frame the conceptions of oceans that I discuss is the exclusion of a diversity of human-ocean relations from consideration. To counter the exclusionary practices of Western discourses I find that robust democratic processes are essential for just ocean existences. The importance of democratic processes is not only that they constitute ethical processes, and should be valued highly for that reason, but also because of a capacity to produce and deliver improved knowledge about the oceans and transform human-ocean relations. I advocate in particular the approach to political epistemology of Bruno Latour as one way to work toward just ocean existences. In the approach I advocate, oceans participate in democratic processes as agents, not as mere objects awaiting human benevolence or exploitation.
41
Kennedy, Deborah Jane. "Ocean views : an investigation into human-ocean relations /." Kennedy, Deborah Jane (2007) Ocean views: an investigation into human-ocean relations. PhD thesis, Murdoch University, 2007. http://researchrepository.murdoch.edu.au/123/.
Full textAbstract:
This dissertation investigates some conceptions of oceans in modern Western societies that are highly influential in shaping human-ocean relations. My main aim in this dissertation is to demonstrate that the Western discourses of law, science and the aesthetic of the sublime illuminate characteristics of human-ocean relations in Western societies. I argue that the conceptions developed and perpetuated in the discourses of law, aesthetics and science unnecessarily constrain the possibilities for human-ocean relations and undermine just existences of oceans. A further aim of this dissertation is to set out an ethical political approach that is inclusive of a diversity of ocean views that facilitate improved knowledge about the oceans and transform dominant human ocean relations into more just relations.
In approaching my critique of Western discourses of law, aesthetics and science I canvas a range of philosophical, social and political theories, but make most use of the insights of feminist and ecological feminist thinkers into forms of oppression and environmental justice. I also move beyond critique to set out an approach for structuring ocean policy debates and outcomes with a form of political epistemology that de-centres influential Western conceptions of oceans and is inclusive of a diversity of perspectives.
In carrying out this dissertation's investigation I find that particular conceptions of oceans in the discourses of law, aesthetics and science narrowly define how Western human subjects think, feel and interact with oceans. These discourses provide a dominant position for Western subjects over those of other people and the oceans. This is how, in basic terms, I suggest that Western discourses undermine just existences for oceans. A common feature in the discourses that frame the conceptions of oceans that I discuss is the exclusion of a diversity of human-ocean relations from consideration. To counter the exclusionary practices of Western discourses I find that robust democratic processes are essential for just ocean existences. The importance of democratic processes is not only that they constitute ethical processes, and should be valued highly for that reason, but also because of a capacity to produce and deliver improved knowledge about the oceans and transform human-ocean relations. I advocate in particular the approach to political epistemology of Bruno Latour as one way to work toward just ocean existences. In the approach I advocate, oceans participate in democratic processes as agents, not as mere objects awaiting human benevolence or exploitation.
42
Zampierin, Daniele. "Multi-analytical characterization of ceramics from Dhofar (Southern Oman): provenance and trade." Master's thesis, Universidade de Évora, 2020. http://hdl.handle.net/10174/29046.
Full textAbstract:
Os sítios arqueológicos de Sumhuram (séculos III a II aC - início V dC) e Inqitat (primeiro milénio
aC - séculos I a II dC) estão envolvidos num dos exemplos mais importantes de rede de comércio
a grande escala na antiguidade: a rede de comércio marítimo no Oceano Índico. Ambos,
localizados na Província de Dhofar (Omã), ao longo do Wadi Darbat, estiveram diretamente
envolvidos neste intercâmbio, sendo um exemplo extraordinário da sua complexidade.
A atenção deste trabalho está focada na caracterização do material cerâmico Local e Indiano, de
ambos os locais, abrangendo idades desde o final do primeiro milénio aC até ao século IV dC.
Realizou-se uma abordagem multi-analítica complementar com o objetivo de caracterização das
cerâmicas e validação das proveniências resultantes da abordagem tipológica. As técnicas
utilizadas na análise foram Difração de raio-X (XRD), Análise Petrográfica, Espectrometria de
massa por plasma acoplado indutivamente (ICP-MS), perda ao rubro (LOI) e Microscopia
eletrónica de varrimento acoplado a espectroscopia de energia dispersiva de raios-X (SEM- EDS).
Os resultados obtidos identificam 8 grupos distintos com base na composição-fabric
(desengordurante rico em conchas (ST), desengordurante rico em argilito (SF), fabric rico em
talco (TF), fabric rico em basalto (BF), desengordurante rico em arroz (RT), material fino (FF),
desengordurante médio-grosseiro em fabric fino (MLF) e desengordurante rico em conchas e
areia (SSF)) traduzindo assinaturas geológicas muito distintas e destacando assim a enorme
variabilidade na origem das matérias-primas. A maioria dos grupos tipológicos definidos como
Indianos são aqui confirmados como provenientes do subcontinente indiano, mas a classificação
tipológica existente não reflete o agrupamento fabric-composicional. Dentro dos grupos Locais
(ST, SF e TF), a presença do grupo de cerâmica rica em talco (TF) e proveniente do Iémen levanta
a discussão sobre o significado de “Local”.
Embora não seja possível associar diferentes matérias-primas com rotas comerciais estabelecidas,
a variabilidade dos grupos indianos identificados implica a participação de várias áreas do
subcontinente indiano na rede de comércio do Oceano Índico: Gujarat e a região centro-oeste, sul
da Índia, Sri Lanka e a planície aluvial do norte da Índia. Os resultados destacam a grande
extensão geográfica da rede de comércio, mas mais importante, sublinham o papel fundamental
da abordagem multi-analítica no apoio à identificação de proveniências, representando o ponto
de partida para uma nova abordagem de base científica para o fenómeno da globalização do
Oceano Índico; Abstract:
Multi-analytical characterization of ceramics from Dhofar (Southern Oman): provenance and
trade.
The archaeological sites of Sumhuram (3rd
-2
nd century BC until the early 5th century AD) and
Inqitat (1st millennium BC until the 1st
-2
nd century AD), are involved in one of the most important
examples of large-scale trade network in the antiquity: the maritime trade network connecting the
coasts of the Indian Ocean. Both sites, located in the Governorate of Dhofar in Oman, along the
Wadi Darbat, were directly involved in the network being an extraordinary example of its
complexity.
The attention of this work is focused on the material characterization of both local and Indian
pottery from both sites spanning from the late 1st millennium BC until the 4th century AD. A multianalytical complementary approach was carried out in order to characterize the ceramics and
validate the provenance identification resulting from the typological approach. The techniques
used in the analysis are X-Ray Diffraction (XRD), petrographic analysis, Inductively Coupled
Plasma Mass Spectrometry (ICP-MS), Loss on Ignition (LOI) and Scanning Electron Microscope
coupled to Energy Dispersive X-ray Spectroscopy (SEM-EDS).
The results obtained identify 8 different fabric-compositional groups (Shell-Temper (ST), Shalerich Fabric (SF), Talc-rich Fabric (TF), Basalt-rich Fabric (BF), Rice Temper (RT), Fine Fabric
(FF), Medium-Large temper grains in fine Fabric (MLF) and the Shell and Sand rich Fabric
(SSF)) with very distinct geological signatures highlighting the enormous variability in the origin
of raw materials. Most of the typological groups defined as Indian are here confirmed as actually
from India, but the specific typological classification does not reflect the fabric grouping. Within
local groups (ST, SF and TF) the presence of a pottery group (TF) coming from Yemen raises the
discussion about the meaning of “local”.
Although it is not possible to associate different raw materials with specific known commercial
routes, the variability of the Indian fabric-compositional groups indicates the participation of
several areas of the Indian subcontinent in the Indian Ocean trade network: Gujarat and the
central-west region, south of India, Sri Lanka and the alluvial plane of the north of India. The
results highlight the large geographical extension of the trade network, but, more importantly,
they underline the fundamental role of multi-analytical approach in support to the provenance
identification representing the starting point for a new scientific-based approach to the Indian
Ocean globalisation phenomenon.
43
Lefao, Maya Taliilagi. "Fa'aSamoa: An Afro-Oceanic Understanding of Epistemology through Folktales and Oral History." Master's thesis, Temple University Libraries, 2017. http://cdm16002.contentdm.oclc.org/cdm/ref/collection/p245801coll10/id/462913.
Full textAbstract:
African American StudiesM.A.
Often disconnected from the African diaspora, the Black South Pacific is constantly laid to the wayside. My research works to shed light on the voices of Afro-Oceanic scholars who are fully capable of articulating their own narratives based on their traditional foundational knowledge that may not align with standard western notions of knowledge but in fact create a system or methods of knowledge unique to the Afro-Oceanic community and traditions. The indigenous Afro-Oceanic agenda of self-determination, indigenous rights and sovereignty, integrity, spiritual healing, reconciliation and humble morality, builds capacity towards a systematic change and re-acknowledgement of indigenous Afro-Oceanic epistemologies. By identifying and analyzing indigenous Oceanic epistemologies, ontologies, and cosmologies, my research seeks to place Afro-Oceanic peoples within the broader African Diaspora. Scholars throughout Afro-Oceania such as Dr. A.M Tupuola, Dr. Vaioleti T.M, and Dr. Helu-Thaman inter
Temple University--Theses
44
Banerjee, S. "Ocean energy assessment : an integrated methodology." Thesis, Coventry University, 2011. http://curve.coventry.ac.uk/open/items/16196d0d-e671-489a-ba71-f20cdb6c8df3/1.
Full textAbstract:
The huge natural energy resources available in the world’s oceans are attracting increasing commercial and political interest. In order to evaluate the status and the degree of acceptability of future Ocean Energy (OE) schemes, it was considered important to develop an Integrated Assessment Methodology (IAM) for ascertaining the relative merits of the competing OE devices being proposed. Initial studies included the gathering of information on the present status of development of the ocean energy systems on wave, OTEC and tidal schemes with the challenges faced for their commercial application. In order to develop the IAM, studies were undertaken for the development and standardization of the assessment tools focussing on: • Life Cycle Assessment (LCA) on emission characteristics. • Energy Accounting (EA) studies. • Environmental Impact Assessment (EIA) over different environmental issues. • Resource captures aspects. • Defining economy evaluation indices. The IAM developed from such studies comprised of four interrelated well defined tasks and six assessment tools. The tasks included the identification of the modus operandi on data collection to be followed (from industry) for assessing respective OE devices, and also advancing relevant guidelines as to the safety standards to be followed, for their deployment at suitable sites. The IAM as developed and validated from case studies in ascertaining relative merits of competing OE devices included: suitable site selection aspects with scope for resource utilisation capability, safety factors for survivability, scope for addressing global warming & energy accounting, the environmental impact assessment both qualitatively and quantitatively on different environmental issues, and the economic benefits achievable. Some of the new ideas and concepts which were also discovered during the development of the IAM, and considered useful to both industry and researchers are given below: • Relative Product Cost (RPC) ratio concept- introduced in making an economic evaluation. This is considered helpful in sensitivity analysis and making design improvements (hybridising etc) for the cost reduction of OE devices. This index thus helps in making feasibility studies on R&D efforts, where the capital cost requirement data and life span of the device is not well defined in the primary stages of development. • Determination of the threshold limit value of the barrage constant - considered useful in determining the efficacy of the planning process. The concept ascertained the relative efficiency achieved for various barrage proposals globally. It could also be applied to suggest the revisions required for certain barrage proposals and also found useful in predicting the basin area of undefined barrage proposal for achieving economic viability. • Estimations made on the future possibility of revenue earnings from the by-products of various OTEC types, including the scope of chemical hubs from grazing type OTEC plants. • Determination of breakeven point- on cost versus life span of wave and OTEC devices studied, which is useful in designing optimum life of the concerned devices. The above stated multi-criterion assessment methodology, IAM, was extended leading to the development of a single criterion model for ascertaining sustainability percent achievable from an OE device and termed IAMs. The IAMs was developed identifying 7 Sustainability Development Indices (SDI) using some the tools of the IAM. A sustainability scale of 0-100 was also developed, attributing a Sustainability Development Load Score (SDLS) percentage distribution pattern over each SDIs, depending on their relative importance in achieving sustainability. The total sum of sustainability development (SD) gained from each SDI gave the IAMs (for the concerned device), indicating the total sustainable percentage achieved. The above IAMs developed, could be applied in ranking OE devices alongside the unsustainable coal power station. A mathematical model of estimating the IAMs was formulated, in order to ascertain the viability to the sustainable development of any energy device. The instruments of IAM and IAMs which have been developed would be helpful to the OE industry in ascertaining the degree of acceptability of their product. In addition it would also provide guidelines for their safe deployment by assessing the relative merits of competing devices. Furthermore, IAM and IAMs would be helpful to researchers undertaking feasibility studies on R&D efforts for material development research, ‘hybridization studies’ (as also new innovations), cost reduction, the performance improvement of respective devices, and any economic gains. With future advancements in OE systems and the availability of field data from large scale commercial applications, the specific values/data of the IAM & IAMs may be refined, but the logic of the models developed in this research would remain the same.
45
Кравченко, Наталія Олександрівна, Наталия Александровна Кравченко, Nataliia Oleksandrivna Kravchenko, and I. Bodnar. "Ocean energy." Thesis, Видавництво СумДУ, 2011. http://essuir.sumdu.edu.ua/handle/123456789/13490.
Full text
46
Irrgang, Christopher [Verfasser]. "Characterization of oceanic signatures in the Earth's magnetic field in view of their applicability as ocean model constraints / Christopher Irrgang." Berlin : Freie Universität Berlin, 2017. http://d-nb.info/1137867795/34.
Full text
47
Dusek, Daniel P. "Ocean mixed layer biological response to transient ocean events." Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 1997. http://handle.dtic.mil/100.2/ADA340990.
Full textAbstract:
Thesis (M.S. in Physical Oceanography) Naval Postgraduate School, September 1997."September 1997." Thesis advisor(s): Roland W. Garwood. Includes bibliographical references (p. 61-63). Also available online.
48
Bednarsek, Nina. "Vulnerability of Southern ocean pteropods to anthropogenic ocean acidification." Thesis, University of East Anglia, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.533722.
Full text
49
Kennerson, Elliott Doran. "Ocean Pictures the construction of the ocean on film /." Thesis, Montana State University, 2008. http://etd.lib.montana.edu/etd/2008/kennerson/KennersonE1208.pdf.
Full textAbstract:
Thesis (MFA)--Montana State University--Bozeman, 2008.Typescript. Chairperson, Graduate Committee: Ronald Tobias. Sealed Off is a DVD accompanying the thesis. Includes bibliographical references (leaves 31-35).
50
Hudeček, Michal. "Odlišení produktů BONEGA pomocí strategie modrého oceánu." Master's thesis, Vysoká škola ekonomická v Praze, 2009. http://www.nusl.cz/ntk/nusl-17300.
Full textAbstract:
At the moment, one of the biggest problems BONEGA company is dealing with is blocked access to wholesale networks by strong multinational corporations. One of the solutions is to introduce such unique and different products that customers force wholesales to offer BONEGA products as other competitors would not provide comparable devices. This thesis evaluate existing approaches to differantiation. The most suitable solution for current situation of BONEGA is blue ocean strategy. However, it has several unsolved issues, especially when applied to manufacturing firm with wide range of products, that are being solved in this paper. In order to gain long term competitive advantage based on value innovation, blue ocean strategy must be implemented into company's culture. Therefore a pilot realization of the process was undertaken. It brought several new ideas for differentiation and also valuable knowledge about adoption of the process into day-to-day company life. Those findings are also part of this work.