Дисертації з теми "Antarctic Ocean Climate"
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Williams, Adam Peter. "Antarctic climate : ocean fluxes and variability." Thesis, University of Southampton, 2008. https://eprints.soton.ac.uk/63753/.
Повний текст джерелаGoddard, Paul B., Carolina O. Dufour, Jianjun Yin, Stephen M. Griffies, and Michael Winton. "CO2-Induced Ocean Warming of the Antarctic Continental Shelf in an Eddying Global Climate Model." AMER GEOPHYSICAL UNION, 2017. http://hdl.handle.net/10150/626296.
Повний текст джерелаBoehme, Lars. "The frontal system of the Antarctic Circumpolar Current : marine mammals as ocean explorers." Thesis, St Andrews, 2008. http://hdl.handle.net/10023/687.
Повний текст джерелаHenley, Sian Frances. "Climate-induced changes in carbon and nitrogen cycling in the rapidly warming Antarctic coastal ocean." Thesis, University of Edinburgh, 2013. http://hdl.handle.net/1842/7626.
Повний текст джерелаGraham, Robert M. "The role of Southern Ocean fronts in the global climate system." Doctoral thesis, Stockholms universitet, Institutionen för geologiska vetenskaper, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-108736.
Повний текст джерелаAt the time of the doctoral defense, the following paper was unpublished and had a status as follows: Paper 4: Submitted.
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.
Повний текст джерелаSuprenand, Paul Mark. "Investigations for utilizing pteropods as bioindicators of environmental change along the western Antarctic Peninsula." Scholar Commons, 2013. http://scholarcommons.usf.edu/etd/4588.
Повний текст джерелаSleadd, Isaac Martin. "CCAAT/Enhancer-Binding Protein Delta (C/EBP-delta) Expression in Antarctic Fishes: Implications for Cell Cycle and Apoptosis." PDXScholar, 2013. https://pdxscholar.library.pdx.edu/open_access_etds/994.
Повний текст джерелаDonat-Magnin, Marion. "Variabilité atmosphérique en Antarctique de l'Ouest : Impact sur la circulation océanique et sur le bilan de masse de surface de la calotte Interannual Variability of Summer Surface Mass Balance and Surface Melting in the Amundsen Sector, West Antarctica." Thesis, Université Grenoble Alpes (ComUE), 2019. http://www.theses.fr/2019GREAU032.
Повний текст джерелаWest Antarctica, and particularly the Amundsen sector, has shown since the 1990s a large increase of mass loss related to coastal glacier acceleration in response to an increase of oceanic melt underneath ice shelves. Ice shelves play a buttressing role for ice-stream and increased oceanic melt therefore lead to ice shelves thinning and glacier acceleration, which contributes to sea level rise. West Antarctica is of particular concern because its configuration is prone to marine ice-sheet instability. It has been suggested that ice shelves weaken under large surface melt in a warmer climate (hydrofracturing), possibly leading to another kind of instability. Instabilities could be slowed down or compensated by future Surface Mass Balance (SMB) that consists mainly of snowfall, sporadic rainfall, and is slightly reduced by sublimation and runoff. The main objective of this PhD work is to model the atmospheric and oceanic processes that will most likely affect the future West Antarctic contribution to sea level rise.First, oceanic projections have been developed using the NEMO ocean model. The ocean circulation induced by ice-shelf basal melting affects the ocean response to future changes in surface winds. Therefore, models that do not represent ice-shelf cavities produce wrong warming patterns around Antarctica. A positive feedback between oceanic melting and grounding-line retreat has been identified and can increase melt rates by a factor of 2.5. These results are strong incentive to couple ocean and ice sheet models, although the projections proposed here are relatively idealized.To run SMB and surface melting projections, an atmospheric model with a fine representation of polar processes, including those related to the snowpack, is needed. MAR is found to be an appropriate tool to simulate the present-day surface climate in the Amundsen region. We find that none of the large climate modes of variability (ASL, SAM, ENSO) explains more than 50% of surface melt and SMB summer variance at the interannual timescale. The use of climate mode variability projections to estimate the future surface climate of West Antarctica is therefore not trivial.Forced by the CMIP5 multi-model mean under the RCP8.5 scenario, MAR predicts an increase of SMB by 30-40% for the end of the 21st century. This increase corresponds to 0.33 mm yr-1 of sea level drop down, which is higher than the current West Antarctic contribution of ~0.26 mm yr-1 from ice dynamics. Surface melt is also projected to increase by a factor of 5 to 15 over the Amundsen ice shelves, but most of it is projected to refreeze in the annual snow layer, so future melting should not have a strong contribution to SMB or hydrofracturing.To conclude we show that coupled ocean and ice sheet climate models are essential to simulate the future of Antarctica and Southern Ocean. A fine representation of surface melt and refreezing processes within the snowpack is also crucial as possible hydrofracturing is threatening in a warmer climate and it comes within a delicate equilibrium between snowfall, air temperature, and feedback related to albedo and humidity
Gregory, Thomas R. "Holocene sea ice-ocean-climate variability from Adélie Land, East Antarctica." Thesis, Cardiff University, 2012. http://orca.cf.ac.uk/41566/.
Повний текст джерелаPereira, Janini. ""Variabilidade do Oceano Austral usando um modelo acoplado de circulação geral"." Universidade de São Paulo, 2003. http://www.teses.usp.br/teses/disponiveis/21/21132/tde-24102003-125856/.
Повний текст джерелаIn this study the climatic variability of the Southern ocean and the Antarctic Circumpolar Wave (ACW) are investigated. The National Center for Atmospheric Research/ Community System Model _ NCAR CCSM coupled model 150 years simulation data is compered with the climatology data from the Nacional Center for Envirommental Prediction - NCEP/NCAR Re-analysis, for a period from january/1948 until july/2002. Annual and seasonal climatology and harmonic analysis are used for the following variables: sea surface temperature (SST), sea level pressure (SLP), meridional and zonal wind. Hovmoeller diagrams, potencial spectra and statistics methods such as Empirical Ortogonal Functions (EOF) and Singular Value Decomposition (SVD) are used to analyze changes in interannual behavior of this variables.
Junttila, J. (Juho). "Clay minerals in response to Mid-Pliocene glacial history and climate in the polar regions (ODP, Site 1165, Prydz Bay, Antarctica and Site 911, Yermak Plateau, Arctic Ocean)." Doctoral thesis, University of Oulu, 2007. http://urn.fi/urn:isbn:9789514283680.
Повний текст джерелаBenoist, Jean Pierre. "Analyse spectrale de signaux glaciologiques : étude des glaces sédimentaires déposées à Dôme C, morphologie du lit d'un glacier : [thèse soutenue sur un ensemble de travaux]." Grenoble 1, 1986. http://www.theses.fr/1986GRE10112.
Повний текст джерелаKrinner, Gerhard. "Simulations du climat des calottes de glace." Phd thesis, Université Joseph Fourier (Grenoble), 1997. http://tel.archives-ouvertes.fr/tel-00716408.
Повний текст джерелаRitz, Catherine. "Un modèle thermo-mécanique d'évolution pour le bassin glaciaire Antarctique Vostok-Glacier Byrd : Sensibilité aux valeurs des paramètres mal connus." Phd thesis, Grenoble 1, 1992. http://tel.archives-ouvertes.fr/tel-00693923.
Повний текст джерелаEdynak, Elsa. "Le droit international applicable à l'océan Arctique : l’adéquation d’un ensemble juridique complexe à un espace spécifique." Thesis, Normandie, 2019. http://www.theses.fr/2019NORMR139.
Повний текст джерелаClimate change and the disruption it implies in the Arctic have really renewed the interest in this space. This raises issues of different scales (both regional and global), but also of different natures (economic, political, social, environmental), which constitute as many legal issues and question the relevance of the applicable law. However, and this is the main legal issue here: the existing legal framework is extremely complex, whose consistency and relevance concerning the region have been widely questioned. But to this unique problem - com-plexity - the authors do not seem to agree on the solutions to adopt. These differences underline the interest to determine whether the legal framework for the Arctic Ocean can be considered as "adequate" in the sense that it would enable a management that meets the criteria of a satisfying legal system. Regarding the method, the study demanded to put the apparent disorder in order. To this end, systematization was necessary; it was done through the creation of a synoptic table analyzing all the standards of international law applicable to the region,. In conclusion, despite its diversity, the legal framework can nevertheless be considered satisfactory from a substantive (completeness) and formal (coherence) point of view. Beyond simple coherence, the current cons-truction of an Arctic law leads to the identification of an scheduling process at the regional level, this framework resembling more and more a real "legal system". This regionalisation is legally essential. Nevertheless, it must be recognized that it does not ensure the worldwide action which remains essential in the face of the global problem that is climate change. If it constitutes a probably necessary step, it represents above all an additional step in this generalized implementation and therefore reinforces the fragmentation of international law, and its complexity
Cosme, Emmanuel. "Cycle du soufre des moyennes et hautes latitudes Sud dans un modèle de circulation générale atmosphérique." Phd thesis, Université Joseph Fourier (Grenoble), 2002. http://tel.archives-ouvertes.fr/tel-00705168.
Повний текст джерелаMoorman, Ruth. "Response of Antarctic ocean circulation to increased meltwater." Thesis, 2019. http://hdl.handle.net/1885/187134.
Повний текст джерелаMorrison, Adele Kim. "Response of the Southern Ocean circulation to changes in global climate." Phd thesis, 2014. http://hdl.handle.net/1885/155903.
Повний текст джерелаDe, Boer Agatha M. Nof Doron. "The Bering Strait and the southern ocean winds' grip on world climate." 2003. http://etd.lib.fsu.edu/theses/available/etd-08312003-215801/.
Повний текст джерелаAdvisor: Dr. Doron Nof, Florida State University, College of Arts and Sciences, Dept. of Oceanography. Title and description from dissertation home page (viewed Oct. 6, 2003). Includes bibliographical references.
Wiederwohl, Christina 1980. "The Ross Sea Response to Evolving Ocean-Ice Interactions in a Changing Climate." Thesis, 2012. http://hdl.handle.net/1969.1/148296.
Повний текст джерелаPescadinha, Patrícia Pereira. "Fatty acid profile of zooplankton species on the Antarctic Southern Ocean." Master's thesis, 2020. http://hdl.handle.net/10316/93964.
Повний текст джерелаThe Antarctica and Southern Ocean ecosystems have been suffering changes through the last 30 years, in particular raising of the ocean temperature. These changes occur in a non-circumpolar distribution, for which there are more affected zones than others and, consequently more species in particular regions. It is necessary to understand how these species deal with the environmental changes that are influencing its habitat and how these changes will alter the global marine ecosystems. As Antarctica is the habitat of numerous endemic species, such studies are urgently needed. Due to climate impacts, it is possible to observe evidence of change in the Antarctic food web, where Antarctic krill (Euphausia superba) has decreased its important role in some regions, allowing other zooplankton species to have that role. It is of extreme importance to study the lower trophic levels of this food web, so it is possible to verify the effects of climate change in the species that live in these waters that may help higher trophic levels. Fatty acid analysis allows to assess the response of species to environmental stressors and identify potential food sources, in a trophic ecology context. The zooplankton species of Euphausia superba, Euphausia triacantha, Themisto gaudichaudii, Thysanoessa spp were collected between December 2016 and January 2017, in three locations with distinct characteristics: Antarctic waters, Intermediate and Sub-Antarctic waters. After GC-MS analysis, it was possible to verify that the species E. triacantha, T. gaudichaudii and Thysanoessa spp. presented a better body condition than E. superba. Besides, it was also possible to observe that these three species all revealed better conditions in waters with a higher temperature (Sub-Antarctic waters) than in waters with lower temperatures, closer to the ones found in the Southern Ocean. However, E. superba exhibited a different fatty acid profile (characterized by the absence of highly unsaturated fatty acids in its constitution and dominance of saturated fatty acids) from what is reported in literature and to what it was found for the remaining species studied in this thesis. Further investigation is needed in order to understand how E. superba deals with climate changes for a better understanding of these results.
Os ecossistemas presentes na Antártida e no Oceano Antártico têm vindo a sofrer alterações ao longo dos últimos 30 anos, especialmente com o aumento de temperatura dos oceanos. Estas alterações não ocorrem de um forma homogénea, pelo que existem zonas mais afetadas do que outras, havendo, também por isso, espécies que são mais afetadas por estas alterações. Torna-se assim necessário perceber como as espécies lidam com estas alterações e como estas mudanças poderão alterar os sistemas marinhos globais. A Antártida é o habitat de numerosas espécies endémicas, tornando-se importante o estudo da sua cadeia trófica num contexto de alterações climáticas. Devido aos impactos ambientais, existe já evidência de uma alteração desta cadeia trófica, com o camarão da Antártida (Antarctic krill Euphausia superba) a diminuir o seu papel preponderante em algumas regiões, passando a outras espécies de zooplâncton esse papel. Assim, é de extrema importância o estudo na base desta cadeia trófica, de modo a analisar os possíveis efeitos de mudanças ambientais nas espécies que habitam na Antártida e com um papel chave para os níveis tróficos mais elevados. A análise do perfil de ácidos gordos permite verificar se as espécies estão em stress devido a mudanças ambientais, num contexto de ecologia trófica. No presente estudo, as espécies de zooplâncton Euphausia superba, Euphausia triacantha e Themisto gaudichaudii e o género Thysanoessa spp. foram recolhidas entre dezembro de 2016 e janeiro de 2017, em 3 locais com características diferentes: águas Antárticas, Intermédias e Sub-Antárticas. Após análise por GC-MS, foi possível verificar que as espécies E. triacanta e T. gaudichaudii e o género Thysanoessa spp. apresentavam uma melhor condição corporal do que E. superba. Além disso, também foi possível verificar que todas estas espécies se encontravam em melhores condições (maior abundância de ácidos gordos na sua composição e maior abundância de ácidos gordos essenciais) em águas com temperaturas mais elevadas (águas sub-Antárticas) do que em águas com temperaturas mais baixas, próximas das encontradas no Oceano Antártico. No entanto, E. superba mostrou um perfil de ácidos gordos distinto dos apresentados pelas outras espécies estudadas nesta tese (independentemente da sua localização) e do que é reportado na literatura (ausência de ácidos gordos altamente insaturados presentes na sua constituição e domínio de ácidos gordos saturados). Mais estudos para compreender as alterações que esta espécie vive nesta região são necessários para um melhor entendimento destes resultados.
Kim, Yong Sun 1976. "Antarctic Circumpolar Current System and its Response to Atmospheric Variability." Thesis, 2012. http://hdl.handle.net/1969.1/148046.
Повний текст джерелаBozzato, Deborah. "The effect of climate change on the carbon balance between photosynthesis and respiration in Antarctic microalgae." 2019. https://ul.qucosa.de/id/qucosa%3A36748.
Повний текст джерелаSwart, Neil Cameron. "The Southern Hemisphere Westerlies and the ocean carbon cycle: the influence of climate model wind biases and human induced changes." Thesis, 2013. http://hdl.handle.net/1828/4657.
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Petrou, K. "From the ice to the open ocean : threats to phytoplankton productivity in the Antarctic marine ecosystem from a changing climate." Thesis, 2010. http://hdl.handle.net/10453/36273.
Повний текст джерелаThe Antarctic marine ecosystem is unique and dynamic, changing seasonally and forming specialised niche habitats including open ocean, sea ice and meltwater environments. Phytoplankton are key species in the structure and function of the Antarctic ecosystem, instrumental in the regions biogeochemistry, fundamental to the food web and strong contributors to global primary production and carbon sequestration. Understanding the photosynthetic plasticity of Antarctic phytoplankton is essential to understanding the effects global change is likely to have on primary production in the region. Through a series of experiments, this thesis explores the processes of light acclimation, photoprotection and photoinhibition in Antarctic microalgae under different environmental stressors, comparing photophysiological responses of species known to inhabit the sea-ice, meltwater and pelagic regions of Antarctic waters. The photosynthetic properties of three Antarctic diatoms (Fragilariopsis cylindrus, Pseudo-nitzschia subcurvata and Chaetoceros sp.) to changes in salinity, temperature and light were compared. Large heterogeneities in the photoprotective capacity of the three species and several distinct physiological strategies in response to the rapid changes in the ambient environment were observed (Publication I). Similarly, photosynthesis and net primary productivity was species-specific with large differences between environmental conditions (Publication II). Fast induction kinetics and pulse amplitude modulated fluorometry were used to demonstrate high levels of flexibility in light acclimation capabilities of sea ice algae from the east Antarctic. Inhibitors and pigment analyses identified xanthophyll cycling as the critical mechanism for photoprotection and preferred means by which sea ice diatoms regulated energy flow to PS1 (Publication III). While immunoblot analyses of natural communities measured minimal D1 protein breakdown in algae exposed to irradiances up to 200 µmol photons m⁻² s⁻¹. These data showed that sea ice diatoms had low intrinsic susceptibility to PSII photoinactivation and strong irradiance-dependent induction of non-photochemical quenching that was independent of protein resynthesis (Publication IV). The remaining chapters investigated photoprotective strategies and photosynthetic plasticity of phytoplankton under nutrient limitation. Nitrogen depletion in F. cylindrus had a strong influence on non-photochemical quenching capacity and resulted in the impairment of photosynthetic electron transport resulting in the formation of Qʙ non-reducing PSII centres within the photosystem (Publication V). The influence of iron-limitation and high light stress on the growth and physiology of Southern Ocean phytoplankton revealed a community-based response of measurable changes in pigment ratios, photosynthetic capacity and community composition (Publication VI). Iron-limited phytoplankton altered the allocation of photosynthetically derived energy, increasing photoprotective pigment pools and down-regulating photochemistry, at the expense of photosynthetic plasticity.