A Comunidade para o Desenvolvimento da África Austral (SADC) é um dos principais processos de integração regional da África. A criação da Comunidade está fundada no processo de descolonização da África Austral e na mobilização dos Estados da Linha de Frente na contenção das políticas de desestabilização da África do Sul durante o período do apartheid. A concepção de regionalismo desenvolvimentista, na qual os processos de integração regionais têm objetivos mais amplos do que os meramente comerciais, vai ao encontro da realidade da África Austral. O conceito de comunidade de segurança também é útil para compreender as relações regionais que envolvem a criação e o desenvolvimento da SADC ao longo das décadas, tendo em vista a sua atuação também nas questões securitárias. O objetivo desse trabalho é analisar a evolução da SADC, desde a sua criação até os anos 2000, enfatizando os aspectos históricos e políticos desse processo. Parte-se do pressuposto de que há uma forte relação entre segurança, desenvolvimento, paz e integração e que não há como a integração econômica aprofundar-se em um contexto de instabilidade político-securitária regional. / The Community for the Southern African Development Community (SADC) is one of the main regional integration processes in Africa. The creation of the Community has its origins in the process of decolonization in Southern Africa and in the Front Line States the mobilization to contain the destabilization policies by South Africa during the apartheid period. The concept of developmental regionalism, in which the processes of regional integration have broader objectives than purely commercial, folows the reality of Southern Africa. The concept of security community is also useful for understanding regional relations involving the creation and development of SADC over the decades, concerning your activity also in security issues. The aim of this study is to analyze the evolution of SADC since its creation until the 2000’s, emphasizing the historical and political aspects of this process. It adopts the assumption that there is a strong relationship between security, development, integration and peace and there is no way to deepen economic integration in a context of regional political and security instability. / La Communauté de Développement de l'Afrique Australe est l'un des principaux processus d'intégration régionale en Afrique . La création de la Communauté est fondée dans le processus de décolonisation en Afrique australe et dans la mobilisation de les État du Linge de Front pour contenir les politiques de déstabilisation de l'Afrique du Sud au cours de la période de l'apartheid. Le concept de régionalisme développementiste, dans lequel les processus d'intégration régionale ont des objectifs plus larges que purement commerciale, répond à la réalité de l'Afrique Australe . Le concept de communauté de sécurité est également utile pour comprendre les relations régionales sur la création et le développement de la SADC au cours des décennies , en vue de ses performances aussi dans les questions sécuritaire . L’objectif de cette étude est d'analyser l'évolution de la SADC depuis sa création jusqu'aux années 2000 , mettant l'accent sur les aspects historiques et politiques de ce processus . Séjours à l'hypothèse selon laquelle il existe une relation forte entre la sécurité, le développement, l'intégration et la paix et il n'ya aucun moyen d'approfondir l'intégration économique dans un contexte d’instabilité politique et securitaire régionale.

A Comunidade para o Desenvolvimento da África Austral (SADC) é um dos principais processos de integração regional da África. A criação da Comunidade está fundada no processo de descolonização da África Austral e na mobilização dos Estados da Linha de Frente na contenção das políticas de desestabilização da África do Sul durante o período do apartheid. A concepção de regionalismo desenvolvimentista, na qual os processos de integração regionais têm objetivos mais amplos do que os meramente comerciais, vai ao encontro da realidade da África Austral. O conceito de comunidade de segurança também é útil para compreender as relações regionais que envolvem a criação e o desenvolvimento da SADC ao longo das décadas, tendo em vista a sua atuação também nas questões securitárias. O objetivo desse trabalho é analisar a evolução da SADC, desde a sua criação até os anos 2000, enfatizando os aspectos históricos e políticos desse processo. Parte-se do pressuposto de que há uma forte relação entre segurança, desenvolvimento, paz e integração e que não há como a integração econômica aprofundar-se em um contexto de instabilidade político-securitária regional. / The Community for the Southern African Development Community (SADC) is one of the main regional integration processes in Africa. The creation of the Community has its origins in the process of decolonization in Southern Africa and in the Front Line States the mobilization to contain the destabilization policies by South Africa during the apartheid period. The concept of developmental regionalism, in which the processes of regional integration have broader objectives than purely commercial, folows the reality of Southern Africa. The concept of security community is also useful for understanding regional relations involving the creation and development of SADC over the decades, concerning your activity also in security issues. The aim of this study is to analyze the evolution of SADC since its creation until the 2000’s, emphasizing the historical and political aspects of this process. It adopts the assumption that there is a strong relationship between security, development, integration and peace and there is no way to deepen economic integration in a context of regional political and security instability. / La Communauté de Développement de l'Afrique Australe est l'un des principaux processus d'intégration régionale en Afrique . La création de la Communauté est fondée dans le processus de décolonisation en Afrique australe et dans la mobilisation de les État du Linge de Front pour contenir les politiques de déstabilisation de l'Afrique du Sud au cours de la période de l'apartheid. Le concept de régionalisme développementiste, dans lequel les processus d'intégration régionale ont des objectifs plus larges que purement commerciale, répond à la réalité de l'Afrique Australe . Le concept de communauté de sécurité est également utile pour comprendre les relations régionales sur la création et le développement de la SADC au cours des décennies , en vue de ses performances aussi dans les questions sécuritaire . L’objectif de cette étude est d'analyser l'évolution de la SADC depuis sa création jusqu'aux années 2000 , mettant l'accent sur les aspects historiques et politiques de ce processus . Séjours à l'hypothèse selon laquelle il existe une relation forte entre la sécurité, le développement, l'intégration et la paix et il n'ya aucun moyen d'approfondir l'intégration économique dans un contexte d’instabilité politique et securitaire régionale.

A Comunidade para o Desenvolvimento da África Austral (SADC) é um dos principais processos de integração regional da África. A criação da Comunidade está fundada no processo de descolonização da África Austral e na mobilização dos Estados da Linha de Frente na contenção das políticas de desestabilização da África do Sul durante o período do apartheid. A concepção de regionalismo desenvolvimentista, na qual os processos de integração regionais têm objetivos mais amplos do que os meramente comerciais, vai ao encontro da realidade da África Austral. O conceito de comunidade de segurança também é útil para compreender as relações regionais que envolvem a criação e o desenvolvimento da SADC ao longo das décadas, tendo em vista a sua atuação também nas questões securitárias. O objetivo desse trabalho é analisar a evolução da SADC, desde a sua criação até os anos 2000, enfatizando os aspectos históricos e políticos desse processo. Parte-se do pressuposto de que há uma forte relação entre segurança, desenvolvimento, paz e integração e que não há como a integração econômica aprofundar-se em um contexto de instabilidade político-securitária regional. / The Community for the Southern African Development Community (SADC) is one of the main regional integration processes in Africa. The creation of the Community has its origins in the process of decolonization in Southern Africa and in the Front Line States the mobilization to contain the destabilization policies by South Africa during the apartheid period. The concept of developmental regionalism, in which the processes of regional integration have broader objectives than purely commercial, folows the reality of Southern Africa. The concept of security community is also useful for understanding regional relations involving the creation and development of SADC over the decades, concerning your activity also in security issues. The aim of this study is to analyze the evolution of SADC since its creation until the 2000’s, emphasizing the historical and political aspects of this process. It adopts the assumption that there is a strong relationship between security, development, integration and peace and there is no way to deepen economic integration in a context of regional political and security instability. / La Communauté de Développement de l'Afrique Australe est l'un des principaux processus d'intégration régionale en Afrique . La création de la Communauté est fondée dans le processus de décolonisation en Afrique australe et dans la mobilisation de les État du Linge de Front pour contenir les politiques de déstabilisation de l'Afrique du Sud au cours de la période de l'apartheid. Le concept de régionalisme développementiste, dans lequel les processus d'intégration régionale ont des objectifs plus larges que purement commerciale, répond à la réalité de l'Afrique Australe . Le concept de communauté de sécurité est également utile pour comprendre les relations régionales sur la création et le développement de la SADC au cours des décennies , en vue de ses performances aussi dans les questions sécuritaire . L’objectif de cette étude est d'analyser l'évolution de la SADC depuis sa création jusqu'aux années 2000 , mettant l'accent sur les aspects historiques et politiques de ce processus . Séjours à l'hypothèse selon laquelle il existe une relation forte entre la sécurité, le développement, l'intégration et la paix et il n'ya aucun moyen d'approfondir l'intégration économique dans un contexte d’instabilité politique et securitaire régionale.

L’Océan austral est l’un des pivot des écosystèmes et du climat de notre planète, qui concentre plus de 20% de la productivité primaire marine mondiale. La complexité de ses réseaux trophiques et son inaccessibilité rendent plus encore qu’ailleurs nécessaire l’utilisation d’espèces bio-indicatrices. Plusieurs espèces de manchots (comme le Manchot Royal et le Manchot Empereur) sont ainsi l’objet de programmes de suivi à long terme. Dans cette étude, nous utilisons les données offertes par la génomique des populations (« RAD-sequencing » couvrant le génome de centaines d'individus issus couvrant la distribution de ces deux espèces) et les représentations numériques du climat de l’IPCC-CMIP5 pour calibrer dans le temps long les analyses démographique plus précises réalisées à l'échelle de quelques générations dans le cadre de suivis démographiques, et mieux comprendre la réponse des manchots au changement climatique. Au-delà de ses conséquences immédiates pour l’étude des Manchots en tant que sentinelles de l’Océan Austral, cette étude montre l’intérêt d’une plus forte intégration de la génomique des populations dans les études démographiques et comportementales. / The Southern Ocean plays a central role in the regulation of the Earth’s climate and ecosystems, and accounts for more than 20% of the world’s marine productivity. The complexity of its trohpic networks and its sheer inaccessibility make the use of bioindicator species more necessary there than anywhere else. Several penguin species (such as the King and the Emperor penguin) are therefore the focus of long-term monitoring programs.In this study, we use the information from population genomics (« RAD-sequencing » data covering the genome of hundreds of individuals from the two species’ full distribution) and from IPCC-CMIP5 numerical climate models to calibrate in the long time the more precise demographic analyses realised in the framework of field surveys, and understand penguin responses to cliamte change. Beyond its implications for the study of penguins as sentinels of the Southern Ocean, our work demonstrates the interest of a stronger integration of population genomics in demographic and behavioural investigation.

Afin d'étudier les processus biogéochimiques de l'Océan Austral, des balises posées sur des éléphants de mer ont permis de récolter en 2009-2010 des profils de variables océanographiques (Chlorophylle a (Chl a), température, salinité, lumière) dans une zone s'étalant du sud des îles Kerguelen jusqu'au continent Antarctique. Cette thèse se penche en particulier sur les données de Chl a, car celle-ci est contenue dans les organismes photosynthétiques qui jouent un rôle essentiel de pompe à carbone. Mais les profils verticaux de Chl a, récoltés peu fréquemment, ne permettent pas d'obtenir une cartographie de cette variable dans cette zone de l'océan. Cependant, nous disposons de profils de lumière, échantillonnés plus souvent. L'objectif était alors de développer une méthodologie permettant de reconstruire de manière indirecte les profils de Chl a à partir des profils de lumière, et qui prenne en compte les caractéristiques de ce type de données qui se présentent naturellement comme des données fonctionnelles. Pour cela, nous avons abordé la décomposition des profils à reconstruire ou explicatifs sur une base de splines, ainsi que les questions d'ajustement associées. Un modèle linéaire fonctionnel a été utilisé, permettant de prédire des profils de Chl a à partir des dérivées des profils de lumière. Il est montré que l'utilisation d'un tel modèle permet d'obtenir une bonne qualité de reconstruction pour accéder aux variations hautes fréquences des profils de Chl a à fine échelle. Enfin, une interpolation par krigeage fonctionnel permet de prédire la concentration en Chl a de nuit, car les mesures de lumière acquises à ce moment-là ne peuvent pas être exploitées. / To study biogeochemical processes in the Southern Ocean, tags placed on elephant seals allowed to collect during 2009-2010 oceanographic variables profiles (Chlorophyll a (Chl a), temperature, salinity, light) in an area ranging from southern Kerguelen until the Antarctic continent. This thesis focuses on Chl a data as it is contained in photosynthetic organisms and these ones play an essential role in the oceanic carbon cycle. The infrequently collected vertical Chl a profiles don't provide a mapping of this variable in this area of the ocean. However, we have light profiles sampled more often. The aim of this thesis was then to develop a methodology for reconstructing indirectly Chl a profiles from light profiles, and that takes into account characteristics of this kind of data that naturally occur as functional data. For this, we adressed the profiles decomposition to rebuild or explanations on splines basis, as well as issues related adjustment. A functional linear model was used to predict Chl a profiles from light profiles derivatives. It was shown that the use of such a model provides a good quality of reconstruction to access high frequency variations of Chl a profiles at fine scale. Finally, a functional kriging interpolation predicted the Chl a concentration during night, as light measurements acquired at that time can't be exploited. In the future, the methodology aims to be applied to any type of functional data.

A complexa interação que ocorre entre os processos oceânicos e atmosféricos no Oceano Austral afeta a circulação oceânica global em diferentes camadas. O Mar de Weddell e o Mar de Ross possuem reconhecida importância na formação da Água de Fundo Antártica (AABW). O objetivo principal deste trabalho é caracterizar as massas de água dos Mares de Weddell e Ross, através dos dados mais recentes de reanálise oceânica SODA (Simple Ocean Data Assimilation). Através da técnica de separação de massas de água Análise Multiparamétrica Ótima (AMO) foi possível a identificação de 3 principais massas de água no Mar de Ross: Água Profunda Circumpolar Superior (UCDW), Água Profunda Circumpolar Inferior (LCDW) e Água de Plataforma de Baixa Salinidade (LSSW). A UCDW foi a que apresentou a maior variabilidade, não atingindo a Plataforma de gelo do MR durante os anos de 1950-1974. No Mar de Weddell foi possível a identificação das seguintes massas de água: Água Profunda Cálida (WDW), Água Profunda do Mar de Weddell (WSDW) e Água de Fundo do Mar de Weddell (WSBW). A WDW atingiu valores >70% à 800m. A WSDW possui em seu núcleo valores > 90% entre 2000 e 3500m. A WSBW, apresenta ~100% em profundidades > 4000m. / The complex interaction that occurs between the oceanic and atmospheric processes in the Southern Ocean affects global ocean circulation in different layers. The Weddell and Ross Seas have recognized importance in the formation of Antarctic Bottom Water (AABW). This work aims to characterize the water masses of the Weddell and Ross Seas, using the latest ocean data reanalysis SODA (Simple Ocean Data Assimilation). Through the water masses separation technique, Optimum Multiparameter Analysis (OMP), it was possible to identify three main water masses in Ross Sea: Upper Circumpolar Deep Water (UCDW), Lower Circumpolar Deep Water (LCDW) and Low Salinity Shelf Water (LSSW). UCDW showed the greatest variability, not reaching the Ross Sea Ice Shelf during the years 1950-1974. It was possible to identify the following water masses in Weddell Sea: Warm Deep Water (WDW), Weddell Sea Deep Water (WSDW) and Weddell Sea Bottom Water (WSBW). WDW reached values up to 70% in 800m. WSDW has in its core values > 90% between 2000 and 3500m. WSBW presents a contribution up to 100% at depths > 4000m.

O oceano desempenha papel fundamental na configuração e manutenção do clima da Terra, sendo considerado um dos componentes principais do sistema climático.Diversos estudo foram conduzidos para avaliar as mudanças nos processos climáticos e como o clima, em contrapartida, é afetado por tais mudanças. O presente trabalho visa investigar o impacto das mudanças climáticas na formação de massas de água do oceano austral. Foram analisados resultados de simulação numérica para os séculos XX e XXI pelo modelo CCSM3 para os cenários 20c3m e SRESA1B do IPCC. Através da técnica de separação de mássas de água Análise Otimizada de Parâmetros Múltiplos (OMP) foram identificadas 3 massas de água no Mar de Ross: Água Profunda Circumpolar (CDW); Água da Plataforma de Gelo (ISW); Água de Plataforma de Baixa Salinidade (LSSW). A ISW, precursora da Água de Fundo Antártica (AABW), apresenta maior variação espacial tornando-se mais rasa no século XX e assumindo camadas mais profundas no século XXI. A variação da ISW está relacionada à variação do Modo Anular Sul (SAM) e à variação do gelo marinho. / It has been known for a long time that the ocean plays the most important role on Earth\'s heat budget, what turns it into a major component of the global climate system. Therefore, many studies have been made to assess whether features of climate processes are changing and how may climate itself be affected by these changes. This work aims to look at the impact of climate changes on water masses formation in the Southern Ocean. Results from the 20th century and SRESA1b CCSM3/NCAR simulation (1870 to 2100) were analyzed using the Optimum Multiparameter Analysis (OMP) to separate water masses. Three water masses were identified in the Ross Sea: Circumpolar Deep Water (CDW); Ice Shelf Water (ISW); Low Salinity Shelf Water (LSSW). Simulation results have shown that the ISW gets shallower during the 20th century and then, during the 21stcentury, it gets deeper and occupies the deepest layer by 2100 while it flows towards higher latitudes as AABW. Much closely to what has been shown by observational studies, water masses formation in the Southern Ocean is intrinsically linked to atmospheric vaiability modes, such as the southern annular mode--SAM, and to sea ice variation.

Les modifications environnementales qui affectent aujourd'hui les milieux marins recouvrent des problématiques scientifiques et sociétales majeures, d'autant que ces changements devraient s'accélérer au cours du 21ème siècle. Comprendre et anticiper la réponse de la biodiversité marine à ces changements représente un enjeu scientifique d'actualité. Les approches biogéographiques et macroécologiques constituent un cadre scientifique dans lequel il est possible d'étudier, de décrire, et de comprendre les motifs de distribution des espèces à large échelle et d'estimer leur évolution possible face aux changements environnementaux. C'est notamment le cas dans l'océan Austral où les effets du changement climatique se font déjà sentir et où les modifications environnementales associées pourraient avoir des effets profonds sur la structure et le fonctionnement des écosystèmes. Malgré de récents efforts d'échantillonnage, nos connaissances sur la distribution des espèces dans l’océan Austral comptent encore de nombreuses lacunes attribuables au caractère récent des découvertes, à l'isolement et à l'éloignement de cet océan d'accès difficiles. Dans ce contexte, les objectifs de cette thèse consistaient à mieux comprendre les motifs de distribution d'espèces à l’échelle de l’océan Austral, à mettre en évidence les facteurs qui en sont à l’origine et enfin, à évaluer l’impact du changement climatique sur leur distribution. Pour cela, différents types de modèles de niche écologique (MNE) ont été employés. Les échinides (oursins), organismes communs des communautés benthiques de l’océan Austral ont servi de modèle d'étude pour ce travail. / Current environmental changes, which impact marine environments, cover major scientific and societal issues, especially as these environmental changes are expected to accelerate along the 21st century. Understanding and forecasting the response of marine biodiversity to these changes is a pregnant scientific issue. Biogeographic and macroecological approaches provide a scientific framework for that purpose. They allow describing and understanding species distribution patterns at large spatial scale as well as estimating their potential shift with regards to environmental change. This is particularly true in the Southern Ocean, where the effects of climate change are already occurring and where environmental changes could have a deep and manifold impact on the structure and functioning of marine ecosystems. Despite recent sampling efforts, our knowledge of the Southern Ocean species distributions still faces many shortcomings due to the rather recent discovery of this ocean, its isolation and remoteness along with difficult access conditions. In this context, the aims of this thesis are to better understand the factors that drive species distribution patterns at the Southern Ocean scale, and to assess the impact of climate change on their distribution. For this purpose, different types of Species Distribution Models (SDM) have been used. Echinoids (sea urchins), which are common organisms of benthic communities in the Southern Ocean, have been used as a biological model for this work.

O oceano desempenha papel fundamental na configuração e manutenção do clima da Terra, sendo considerado um dos componentes principais do sistema climático.Diversos estudo foram conduzidos para avaliar as mudanças nos processos climáticos e como o clima, em contrapartida, é afetado por tais mudanças. O presente trabalho visa investigar o impacto das mudanças climáticas na formação de massas de água do oceano austral. Foram analisados resultados de simulação numérica para os séculos XX e XXI pelo modelo CCSM3 para os cenários 20c3m e SRESA1B do IPCC. Através da técnica de separação de mássas de água Análise Otimizada de Parâmetros Múltiplos (OMP) foram identificadas 3 massas de água no Mar de Ross: Água Profunda Circumpolar (CDW); Água da Plataforma de Gelo (ISW); Água de Plataforma de Baixa Salinidade (LSSW). A ISW, precursora da Água de Fundo Antártica (AABW), apresenta maior variação espacial tornando-se mais rasa no século XX e assumindo camadas mais profundas no século XXI. A variação da ISW está relacionada à variação do Modo Anular Sul (SAM) e à variação do gelo marinho. / It has been known for a long time that the ocean plays the most important role on Earth\'s heat budget, what turns it into a major component of the global climate system. Therefore, many studies have been made to assess whether features of climate processes are changing and how may climate itself be affected by these changes. This work aims to look at the impact of climate changes on water masses formation in the Southern Ocean. Results from the 20th century and SRESA1b CCSM3/NCAR simulation (1870 to 2100) were analyzed using the Optimum Multiparameter Analysis (OMP) to separate water masses. Three water masses were identified in the Ross Sea: Circumpolar Deep Water (CDW); Ice Shelf Water (ISW); Low Salinity Shelf Water (LSSW). Simulation results have shown that the ISW gets shallower during the 20th century and then, during the 21stcentury, it gets deeper and occupies the deepest layer by 2100 while it flows towards higher latitudes as AABW. Much closely to what has been shown by observational studies, water masses formation in the Southern Ocean is intrinsically linked to atmospheric vaiability modes, such as the southern annular mode--SAM, and to sea ice variation.

L'océan Austral est une région clé pour la compréhension de la circulation océanique globale et du climat. C'est dans cette région qu'une large majorité des eaux de la planète est ventilée dans la couche de surface avant d'être réexpédiée dans l'océan profond. Ainsi la couche de surface de l'océan Austral est un élément central pour la compréhension de la circulation océanique planétaire. Malgré leur rôle fondamental dans la circulation océanique globale et dans le climat, la structure et les caractéristiques de la couche de mélange sont encore mal comprises dans la région Antarctique en raison d'un manque important d'observations in-situ. Cependant, le programme international MEOP (2004) a conduit au déploiement de milliers de capteurs hydrologiques sur des éléphants de mer, et offre une couverture spatiale de données inédites couvrant l’ensemble du cycle saisonnier. Dans cette thèse, nous exploitons ce jeu de données ainsi que d'autres plus conventionnels, afin de décrire les propriétés climatologiques et la dynamique de la couche de mélange sous la glace de mer en Antarctique. Les transferts verticaux entre la couche de mélange et l’océan plus profond, associés à la circulation de retournement y sont décrits aux échelles de temps saisonnières et inter-annuelles. Les résultats soulignent et quantifient le rôle primordial des flux d’eau douce, issus de la glace de mer et des précipitations, sur la transformation de masses d’eau sous la banquise. Nos conclusions suggèrent que des changements dans l’intensité de ces flux d’eau douce pourraient directement affecter les budgets de densité de la couche de mélange et impacter la circulation de retournement globale. / The Southern Ocean is a key region for the understanding of the global ocean circulation and for the climate as a whole. In this region, a large majority of the ocean’s water masses are ventilated in the surface layer, before being sent back to the deep ocean. The surface layer of the Southern Ocean is therefore a central element for understanding the global ocean circulation. Despite their fundamental role in the global ocean circulation and climate, the structure and characteristics of the mixed-layer are still poorly understood in the Antarctic Polar Region due to a significant lack of in-situ observations.However, the international MEOP program (2004) has led to the deployment of thousands of hydrological sensors on Elephant Seals and offers a unique spatial coverage of new data that cover the entire seasonal cycle. In this thesis, we exploit this dataset and other more conventional data, to bring a new perspective on this unknown region. Based on these observations, we describe the climatological properties and dynamics of the mixed-layer under Antarctic sea-ice. The vertical transfers between the mixed-layer and the deep ocean, associated with the meridional overturning circulation, and the hydrographic variations of the water masses in the mixed-layer, are described at seasonal and inter-annual time scales. The results highlight the critical role of freshwater fluxes, induced by sea-ice and precipitations, on the transformation of water masses under the sea-ice. Our findings suggest that changes in the intensity of these freshwater fluxes would directly affect the buoyancy budgets of the mixed-layer and impact the large-scale overturning circulation.