The goal of this record of study is to examine the major facets involved in managing several petroleum service projects located in three different countries in the Gulf of Guinea simultaneously, while effectively engaging in business development activities for the Oil and Industrial Services Group (OIS). This work also furnishes adequate background on related subject matters to enable understanding of the projects presented. The petroleum services sector is the back bone of the oil and gas industry. Services companies are vital to the success of all petroleum and energy producers in the USA, the Gulf of Guinea and the world. There is a need and demand for these service companies because they play various roles such as logistics, drilling, construction, dredging, pipe laying, procurement, food supply, human resource supply, etc. The Gulf of Guinea comprises of countries from west and central Africa. This project was limited to Nigeria, Equatorial Guinea and Cameroon. This area holds the largest petroleum reserves in Africa and plays a vital role in the global supply of petroleum. The Oil and Industrial Services Group (OIS), plans to establish herself as one of the leading petroleum service companies in this gulf. To manage this expansion, I have taken the role of Gulf of Guinea manager to apply my background as a petroleum engineer as well as my business skills to build a successful division of the company. This work provides a record of study of the management of services, projects and contracts carried out by the OIS group in the gulf of Guinea. The following are the specific projects in the Gulf of Guinea that I participated in: Managing delivering, maintenance and marketing of offshore vessels, Offshore pipe laying project, Integrated pipeline maintenance project, Development a petroleum technical training facilities, Agbami pipe insulation project, Engineering lift project and Capital budgeting analysis for potential investments. The details of the specific tasks of the job, including objectives, description, managerial role, nontechnical aspects, approaches, information sources, discussions and contributions are projected in the body of this literature.

Tendo em vista a ascensão da costa ocidental africana como uma fonte alternativa de fornecimento de petróleo ao mercado mundial no período contemporâneo, este trabalho busca responder ao seguinte questionamento: quais as implicações políticas e securitárias da exploração do petróleo na região do Golfo da Guiné, a partir dos anos 2000? Como objetivos do estudo, propõe-se a investigação da influência desse recurso energético nas características dos Estados da região, compreender sua relação com a formação de instituições como as companhias nacionais de petróleo, avaliar sua influência no interesse estrangeiro e na ocorrência de conflitos da região. Para responder o problema de pesquisa, foi realizada ampla revisão bibliográfica em fontes especializadas, relatórios e organismos internacionais. Na primeira seção, examina-se o petróleo no Golfo da Guiné, a competição pelos recursos africanos, a indústria do petróleo na Nigéria e em Angola, e o debate sobre a maldição dos recursos naturais. Na segunda parte são investigadas as implicações políticas e securitárias do petróleo, avaliando suas consequências para as instituições e características do Estado. Em seguida, são avaliados os interesses dos EUA e China na zona, a evolução da Comissão do Golfo da Guiné e os conflitos associados ao petróleo. Por fim, aprofunda-se o estudo da Nigéria, o maior produtor da região, analisando a história do petróleo no país, o conflito no Delta do Níger, e as associações entre exploração de petróleo e política externa. / Considering the rise of the West African coast as an alternative source of oil supply to the world market in the contemporary period, this paper seeks to answer the following question: what are the political and security implications of oil exploration in the Gulf of Guinea, from the 2000's? This study aims to investigate the influence of this energy resource on the characteristics of the states of the region, to understand its relationship with the formation of institutions such as national oil companies, to evaluate their influence on foreign interest and on the occurrence of conflicts in the region. In order to answer the research problem, a bibliographical review was carried out, using specialized sources, reports and documents of international organizations. The first section examines oil in the Gulf of Guinea, the scramble for African resources, the oil industry in Nigeria and Angola, and the debate over the curse of natural resources. The second part investigates the political and security implications of petroleum, evaluating its consequences for the institutions and characteristics of the state. Next, the US and Chinese interests in the zone are evaluated, the Gulf of Guinea Commission's evolution and the conflicts associated with oil in the GG. Finally, the study of Nigeria, the largest producer in the region, examining the history of oil in the country, the conflict in the Niger Delta, and the associations between oil exploration and foreign policy is explored.

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Tendo em vista a ascensão da costa ocidental africana como uma fonte alternativa de fornecimento de petróleo ao mercado mundial no período contemporâneo, este trabalho busca responder ao seguinte questionamento: quais as implicações políticas e securitárias da exploração do petróleo na região do Golfo da Guiné, a partir dos anos 2000? Como objetivos do estudo, propõe-se a investigação da influência desse recurso energético nas características dos Estados da região, compreender sua relação com a formação de instituições como as companhias nacionais de petróleo, avaliar sua influência no interesse estrangeiro e na ocorrência de conflitos da região. Para responder o problema de pesquisa, foi realizada ampla revisão bibliográfica em fontes especializadas, relatórios e organismos internacionais. Na primeira seção, examina-se o petróleo no Golfo da Guiné, a competição pelos recursos africanos, a indústria do petróleo na Nigéria e em Angola, e o debate sobre a maldição dos recursos naturais. Na segunda parte são investigadas as implicações políticas e securitárias do petróleo, avaliando suas consequências para as instituições e características do Estado. Em seguida, são avaliados os interesses dos EUA e China na zona, a evolução da Comissão do Golfo da Guiné e os conflitos associados ao petróleo. Por fim, aprofunda-se o estudo da Nigéria, o maior produtor da região, analisando a história do petróleo no país, o conflito no Delta do Níger, e as associações entre exploração de petróleo e política externa. / Considering the rise of the West African coast as an alternative source of oil supply to the world market in the contemporary period, this paper seeks to answer the following question: what are the political and security implications of oil exploration in the Gulf of Guinea, from the 2000's? This study aims to investigate the influence of this energy resource on the characteristics of the states of the region, to understand its relationship with the formation of institutions such as national oil companies, to evaluate their influence on foreign interest and on the occurrence of conflicts in the region. In order to answer the research problem, a bibliographical review was carried out, using specialized sources, reports and documents of international organizations. The first section examines oil in the Gulf of Guinea, the scramble for African resources, the oil industry in Nigeria and Angola, and the debate over the curse of natural resources. The second part investigates the political and security implications of petroleum, evaluating its consequences for the institutions and characteristics of the state. Next, the US and Chinese interests in the zone are evaluated, the Gulf of Guinea Commission's evolution and the conflicts associated with oil in the GG. Finally, the study of Nigeria, the largest producer in the region, examining the history of oil in the country, the conflict in the Niger Delta, and the associations between oil exploration and foreign policy is explored.

Tendo em vista a ascensão da costa ocidental africana como uma fonte alternativa de fornecimento de petróleo ao mercado mundial no período contemporâneo, este trabalho busca responder ao seguinte questionamento: quais as implicações políticas e securitárias da exploração do petróleo na região do Golfo da Guiné, a partir dos anos 2000? Como objetivos do estudo, propõe-se a investigação da influência desse recurso energético nas características dos Estados da região, compreender sua relação com a formação de instituições como as companhias nacionais de petróleo, avaliar sua influência no interesse estrangeiro e na ocorrência de conflitos da região. Para responder o problema de pesquisa, foi realizada ampla revisão bibliográfica em fontes especializadas, relatórios e organismos internacionais. Na primeira seção, examina-se o petróleo no Golfo da Guiné, a competição pelos recursos africanos, a indústria do petróleo na Nigéria e em Angola, e o debate sobre a maldição dos recursos naturais. Na segunda parte são investigadas as implicações políticas e securitárias do petróleo, avaliando suas consequências para as instituições e características do Estado. Em seguida, são avaliados os interesses dos EUA e China na zona, a evolução da Comissão do Golfo da Guiné e os conflitos associados ao petróleo. Por fim, aprofunda-se o estudo da Nigéria, o maior produtor da região, analisando a história do petróleo no país, o conflito no Delta do Níger, e as associações entre exploração de petróleo e política externa. / Considering the rise of the West African coast as an alternative source of oil supply to the world market in the contemporary period, this paper seeks to answer the following question: what are the political and security implications of oil exploration in the Gulf of Guinea, from the 2000's? This study aims to investigate the influence of this energy resource on the characteristics of the states of the region, to understand its relationship with the formation of institutions such as national oil companies, to evaluate their influence on foreign interest and on the occurrence of conflicts in the region. In order to answer the research problem, a bibliographical review was carried out, using specialized sources, reports and documents of international organizations. The first section examines oil in the Gulf of Guinea, the scramble for African resources, the oil industry in Nigeria and Angola, and the debate over the curse of natural resources. The second part investigates the political and security implications of petroleum, evaluating its consequences for the institutions and characteristics of the state. Next, the US and Chinese interests in the zone are evaluated, the Gulf of Guinea Commission's evolution and the conflicts associated with oil in the GG. Finally, the study of Nigeria, the largest producer in the region, examining the history of oil in the country, the conflict in the Niger Delta, and the associations between oil exploration and foreign policy is explored.

Les ondes internes sont observées partout dans le monde. Elles ont un rôle important dans la mise en place de la chaine trophique, et elles peuvent avoir un impact sur les activités humaines. Ainsi, dans le Golfe de Guinée, des ondes internes solitaires (OIS) ont provoqué des incidents sur des plateformes pétrolières. L’objectif de la thèse est d’identifier leurs zones de génération, leurs directions de propagation, ainsi que les conditions d’environnement susceptibles de les déclencher. La thèse a comporté deux aspects : d’une part des mesures de courant étaient disponibles et d’autre part la mise en place de modèles numériques. Ces mesures ont montré le passage d’OIS. En outre, les zones de génération potentielles sont identifiées en haut du talus continental. Leur répartition mensuelle a montré une variabilité saisonnière, due à la Mousson Ouest Africaine qui modifie les conditions de stratification au cours de l’année.La modélisation a été réalisée avec HYCOM. Une maquette hydrostatique régionale du Golfe de Guinée a été mise en place. Elle a d’abord été validée en configuration barotrope (océan homogène). Une configuration bicouche a ensuite été testée, et la théorie linéaire des ondes internes a été vérifiée sur ses résultats. Des termes non hydrostatiques ont ensuite été ajoutés dans les équations horizontales du courant de HYCOM, pour modéliser des OIS. L’impact des paramètres physiques, en particulier la force de Coriolis et le forçage barotrope, ainsi que l’effet d’un courant moyen, a été étudié sur des configurations bicouches radiales. Enfin, un canyon a été ajouté au milieu du talus pour évaluer qualitativement les effets d’une bathymétrie 2D sur les OIS. / Internal waves are observed in different locations. They have a key role in the set up of the trophic chain, and they can impact human activities.For instance, in the Gulf of Guinea, internal solitary waves (ISWs) have caused hazards on offshore oil platforms. The aim of the thesis is to identify the generation zones and the directions of propagation of these ISWs, and the environmental conditions (tides, stratification) that can generate them. One the one hand measurements of currents were available, and on the other hand numerical models were used.Measurements of currents were analyzed. Packets of ISWs were identified. Moreover, the potential generation zones of the ISWs, particularly the top of the shelf break, were inferred from their direction of propagation. The monthly repartition of the packets of ISWs revealed a seasonal variability, due to the West African Monsoon, which modified the conditions of the stratification throughout the year.Concerning the modelling, the numerical model HYCOM was used. One regional hydrostatic model of the Gulf of Guinea was built. This regional model was validated for a barotropic configuration (homogeneous ocean) first. Then, a two-layered configuration was set up, and the linear theory of the internal waves was confirmed on the results.Non hydrostatic terms were added to the horizontal velocity equations in HYCOM, to model ISWs. The influence of different physical parameters, such as the Coriolis force, the barotropic forcing, and a mean current was studied on two-layered radial configurations. Finally, a canyon in the middle of the shelf break was set up to assess qualitatively the effect of a 2D bathymetry on the ISWs.

O objetivo deste estudo é apresentar uma reconstrução da fonologia e do léxico do protocrioulo do Golfo da Guiné (PGG). O cenário de surgimento do PGG remonta ao período de colonização portuguesa na ilha de São Tomé, no fim do século XV e no começo do XVI, quando o contato entre populações africanas transplantadas à ilha e colonizadores lusos -- provocado pelo povoamento da região -- resultou na formação de uma língua crioula de base lexical portuguesa, o PGG. Após a formação do protocrioulo, deu-se início à separação geográfica de seus falantes que, outrora alojados em São Tomé, por um lado, são transplantados da ilha, e, por outro, fogem dos engenhos, formando quilombos. Assim, na ilha do Princípe, com a leva de transplantados recém-chegados, o PGG se ramifica em lung\'ie, de modo semelhante, na ilha de Ano Bom, o PGG se desenvolve, transformando-se em fa d\'ambô. Em São Tomé, por sua vez, os falantes de protocrioulo se dividem entre aqueles que ficaram nos núcleos de colonização, onde surge o santome, ao passo que a comunidade quilombola se torna o cenário da especiação do PGG no angolar (FERRAZ, 1974, 1979; SEIBERT, 2004; HAGEMEIJER, 2009). Seguindo os princípios do método histórico-comparativo da Linguística Histórica (THOMASON & KAUFMAN, 1988; KAUFMAN, 1990; HOCK, 1991; FOX, 1995; CROWLEY, 1997[1992]; CAMPBELL, 2004[1998]), foi elaborado um corpus a partir de um conjunto de itens pertencentes ao léxico comum do santome, lung\'ie, fa d\'ambô e angolar, as línguas-filhas do PGG. Contudo, devido a lacunas nas descrições dessas línguas, foi necessário investigar seus sistemas fonológicos de tal modo que este trabalho, devido à sua abrangência e escopo, constitui também uma contribuição ao estudo de suas fonologias. À vista disso, a reconstrução fonológica e lexical do protocrioulo tem como base itens de suas línguas-filhas contemporâneas. Por conseguinte, o estudo se baseia nas fonologias das línguas-filhas e na análise de 536 conjuntos de cognatos, obtidos da literatura e da coleta e reunião de cerca de 2000 itens lexicais. Adicionalmente, apresentamos uma descrição e análise dos processos fonológicos observados no cotejo dos conjuntos de cognatos, tendo em vista que o esquadrinhamento de tais processos pode lançar luzes sobre as características estruturais da fonologia do protocrioulo a partir dos reflexos nas línguas-filhas. Assim, o sistema consonantal do PGG é composto por dezoito consoantes (*p, *b, *t, *d, *k, *g, *f, *v, *s, *z, *m, *n, *ɲ, *r, *l, *ʎ, *w, *j) e o sistema vocálico, por seu turno, constituído por sete vogais orais (*i, *e, *ɛ, a, *ɔ, *o, *u). O sistema acentual do PGG era prevísivel e sensível ao peso silábico. Portanto, o acento se fixava na penúltima sílaba em palavras nominais (ex.: *\'blasu \'braço\'), todavia, deslocava-se para a última quando a sílaba era pesada (ex.: *bɔ\'tɔN \'botão\'). Verbos apresentavam acento na sílaba final (ex.: *be\'be \'beber\'). Com efeito, os processos fonológicos descritos nas línguas-filhas oferecem evidências para a reconstrução lexical das protoformas. Dessa maneira, a reconstrução do PGG demonstra que a configuração atual das línguas-filhas provém da interação entre o quadro linguístico inicial do protocrioulo em conjunto com uma série de fenômenos fonológicos que atuaram no cenário de especiação. / Abstract: The aim of this study is to present a phonological and lexical reconstruction of the Proto-Creole of Gulf of Guinea (PGG). The emergence scenario of the PGG goes back to the Portuguese colonization period on the island of São Tomé at the end of the fifteenth century and at the beginning of the sixteenth century, when contact between African populations brought to that island as slaves and the Portuguese settlers resulted in the formation of a Portuguese-based Creole. After the formation of the Proto-Creole, the geographical separation of its speakers began: some settlers and their slaves were taken away from São Tomé to the islands of Príncipe and Ano Bom. Thus, within a new environment and with other speakers, the PGG branched into Lung\'ie on the island of Príncipe. Similarly, the PGG developed on the island of Ano Bom, becoming Fa d\'ambô. In São Tomé, in turn, Proto-Creole speakers are divided between those who remained in colonization centers, where Santome arose, and those who formed maroon communities, which became setting for the speciation of PGG into Angolar (FERRAZ, 1974, 1979; SEIBERT, 2004; HAGEMEIJER, 2009). Following the principles of the comparative method of Historical Linguistics (THOMASON & KAUFMAN, 1988; KAUFMAN, 1990, HOCK, 1991, FOX, 1995; CROWLEY, 1997 [1992], CAMPBELL, 2004 [1998]), a corpus was selected from a set of items belonging to the common lexicon of Santome, Lung\'ie, Fa d\'ambô and Angolar, languages derived from the PGG. However, due to gaps in the descriptions of these languages, it was necessary to investigate their phonological systems. Thus, because of its range and scope, this study also offers a contribution to the study of their phonology. Therefore, this study is based on the phonology of the derived languages and on the analysis of 536 sets of cognates. In addition, we present a description and an analysis of the phonological processes observed in the comparison of the sets of cognates. The study of such processes is vital as they shed light on the structural characteristics of the Proto-Creole phonology and also in the modifications on its daughter languages. The PGG consonant system consists of eighteen consonants (*p, *b, *t, *d, *k, *g, *f, *v, *s, *z, *m, *n, *ɲ, *r, *l, *ʎ, *w, *j) . The vocalic system consists of seven vowels (*i, *e, *ɛ, a, *ɔ, *o, *u). The PGG accentual system was predictable, in general, and related to syllabic weight. Therefore, the stress was on the penultimate syllable in nominal words (e.g.: *\'blasu \'arm\'), but moved to the last syllable when it was heavy (e.g.: *bɔ\'tɔN \'button\'). Verbs were stressed on the final syllable (e.g.: *be\'be \'drink\'). Indeed, the phonological processes described for the derived languages provide evidence for the lexical reconstruction of proto-forms. Thus, the reconstruction of PGG shows that the current configuration of derived languages comes from the interaction between the early Proto-Creole linguistic frame and a series of phonological phenomena that acted in the speciation scenario.

O objetivo deste estudo é apresentar uma reconstrução da fonologia e do léxico do protocrioulo do Golfo da Guiné (PGG). O cenário de surgimento do PGG remonta ao período de colonização portuguesa na ilha de São Tomé, no fim do século XV e no começo do XVI, quando o contato entre populações africanas transplantadas à ilha e colonizadores lusos -- provocado pelo povoamento da região -- resultou na formação de uma língua crioula de base lexical portuguesa, o PGG. Após a formação do protocrioulo, deu-se início à separação geográfica de seus falantes que, outrora alojados em São Tomé, por um lado, são transplantados da ilha, e, por outro, fogem dos engenhos, formando quilombos. Assim, na ilha do Princípe, com a leva de transplantados recém-chegados, o PGG se ramifica em lung\'ie, de modo semelhante, na ilha de Ano Bom, o PGG se desenvolve, transformando-se em fa d\'ambô. Em São Tomé, por sua vez, os falantes de protocrioulo se dividem entre aqueles que ficaram nos núcleos de colonização, onde surge o santome, ao passo que a comunidade quilombola se torna o cenário da especiação do PGG no angolar (FERRAZ, 1974, 1979; SEIBERT, 2004; HAGEMEIJER, 2009). Seguindo os princípios do método histórico-comparativo da Linguística Histórica (THOMASON & KAUFMAN, 1988; KAUFMAN, 1990; HOCK, 1991; FOX, 1995; CROWLEY, 1997[1992]; CAMPBELL, 2004[1998]), foi elaborado um corpus a partir de um conjunto de itens pertencentes ao léxico comum do santome, lung\'ie, fa d\'ambô e angolar, as línguas-filhas do PGG. Contudo, devido a lacunas nas descrições dessas línguas, foi necessário investigar seus sistemas fonológicos de tal modo que este trabalho, devido à sua abrangência e escopo, constitui também uma contribuição ao estudo de suas fonologias. À vista disso, a reconstrução fonológica e lexical do protocrioulo tem como base itens de suas línguas-filhas contemporâneas. Por conseguinte, o estudo se baseia nas fonologias das línguas-filhas e na análise de 536 conjuntos de cognatos, obtidos da literatura e da coleta e reunião de cerca de 2000 itens lexicais. Adicionalmente, apresentamos uma descrição e análise dos processos fonológicos observados no cotejo dos conjuntos de cognatos, tendo em vista que o esquadrinhamento de tais processos pode lançar luzes sobre as características estruturais da fonologia do protocrioulo a partir dos reflexos nas línguas-filhas. Assim, o sistema consonantal do PGG é composto por dezoito consoantes (*p, *b, *t, *d, *k, *g, *f, *v, *s, *z, *m, *n, *ɲ, *r, *l, *ʎ, *w, *j) e o sistema vocálico, por seu turno, constituído por sete vogais orais (*i, *e, *ɛ, a, *ɔ, *o, *u). O sistema acentual do PGG era prevísivel e sensível ao peso silábico. Portanto, o acento se fixava na penúltima sílaba em palavras nominais (ex.: *\'blasu \'braço\'), todavia, deslocava-se para a última quando a sílaba era pesada (ex.: *bɔ\'tɔN \'botão\'). Verbos apresentavam acento na sílaba final (ex.: *be\'be \'beber\'). Com efeito, os processos fonológicos descritos nas línguas-filhas oferecem evidências para a reconstrução lexical das protoformas. Dessa maneira, a reconstrução do PGG demonstra que a configuração atual das línguas-filhas provém da interação entre o quadro linguístico inicial do protocrioulo em conjunto com uma série de fenômenos fonológicos que atuaram no cenário de especiação. / Abstract: The aim of this study is to present a phonological and lexical reconstruction of the Proto-Creole of Gulf of Guinea (PGG). The emergence scenario of the PGG goes back to the Portuguese colonization period on the island of São Tomé at the end of the fifteenth century and at the beginning of the sixteenth century, when contact between African populations brought to that island as slaves and the Portuguese settlers resulted in the formation of a Portuguese-based Creole. After the formation of the Proto-Creole, the geographical separation of its speakers began: some settlers and their slaves were taken away from São Tomé to the islands of Príncipe and Ano Bom. Thus, within a new environment and with other speakers, the PGG branched into Lung\'ie on the island of Príncipe. Similarly, the PGG developed on the island of Ano Bom, becoming Fa d\'ambô. In São Tomé, in turn, Proto-Creole speakers are divided between those who remained in colonization centers, where Santome arose, and those who formed maroon communities, which became setting for the speciation of PGG into Angolar (FERRAZ, 1974, 1979; SEIBERT, 2004; HAGEMEIJER, 2009). Following the principles of the comparative method of Historical Linguistics (THOMASON & KAUFMAN, 1988; KAUFMAN, 1990, HOCK, 1991, FOX, 1995; CROWLEY, 1997 [1992], CAMPBELL, 2004 [1998]), a corpus was selected from a set of items belonging to the common lexicon of Santome, Lung\'ie, Fa d\'ambô and Angolar, languages derived from the PGG. However, due to gaps in the descriptions of these languages, it was necessary to investigate their phonological systems. Thus, because of its range and scope, this study also offers a contribution to the study of their phonology. Therefore, this study is based on the phonology of the derived languages and on the analysis of 536 sets of cognates. In addition, we present a description and an analysis of the phonological processes observed in the comparison of the sets of cognates. The study of such processes is vital as they shed light on the structural characteristics of the Proto-Creole phonology and also in the modifications on its daughter languages. The PGG consonant system consists of eighteen consonants (*p, *b, *t, *d, *k, *g, *f, *v, *s, *z, *m, *n, *ɲ, *r, *l, *ʎ, *w, *j) . The vocalic system consists of seven vowels (*i, *e, *ɛ, a, *ɔ, *o, *u). The PGG accentual system was predictable, in general, and related to syllabic weight. Therefore, the stress was on the penultimate syllable in nominal words (e.g.: *\'blasu \'arm\'), but moved to the last syllable when it was heavy (e.g.: *bɔ\'tɔN \'button\'). Verbs were stressed on the final syllable (e.g.: *be\'be \'drink\'). Indeed, the phonological processes described for the derived languages provide evidence for the lexical reconstruction of proto-forms. Thus, the reconstruction of PGG shows that the current configuration of derived languages comes from the interaction between the early Proto-Creole linguistic frame and a series of phonological phenomena that acted in the speciation scenario.

The Gulf of Guinea Highlands is a unique mountane range of volcanic origin, situated on the African mainland in the borther of Nigeria and Cameroon, and the Gulf of Guinea islands of Bioko, S?o Tomé and Príncipe. This area is highly unique as the only large mountains in central and western Africa. The high degree of isolation of these mountains generated high degree of endemism of many groups of organisms; the whole region is thus one of the world biodiversity hotspots (known as the West African Forests). Despite its tremnedous conservation importance, this mountain range is under strong anthropogenic influence, as one of the most densely populated areas in tropical Africa. Despite all these factors, the conservation efforts in West Africa focused mainly on lowland areas of rain forests, whilst only few conservation effort is focused to the mountain habitats. As the other result, the lack of comprehensive biogeographic and phytogeographical studies of mountain flora and fauna is obvious. In this work, I have summarized the results of all crucial studies of the biogeography of the Gulf of Guinea Highlands. I also obtained sequences of three mitochondrial genes (COI, COII, and ND1) of an endemic montane butterfly Bicyclus anisops. Variability in the studied genes was relatively low. Phylogenetic analyses separated haplotypes into 7 well-established groups (1st Mt. Cameroon, 2nd Nkogam I, 3rd Nkogam II, 4th Bakossi-Kupe-Manengouba-Bani, 5th Mbam, 7th Hosséré Enla Fabo 6th all others localities (tj. Bamenda-Banso Mts., Acha Tugi, Mbam, Ngel Nyaki, Gotel Mts.)) but did not significantly resolved relationships among them. Based on the hyplotype diversity of B. anisops as an umbrella species, Mt. Cameroon, Nkogam, Mbam Massif, Mbiame, Hosséré Enla Fabo, Mt. Manengouba, Mt. Kupe and Mt. Oku are considered as localities of the highest conservation importance.

Cette étude s'inscrit dans le cadre de la documentation de la variabilité intrasaisonnière atmosphérique et l'analyse de la prévisibilité sur les régions Afrique Centrale et Golfe de Guinée. Elle porte sur les saisons de l'année pour lesquelles la ZCIT est au dessus de l'équateur. Des travaux menés distinctement sur les mois de Mars à Juin et de Septembre à Novembre, il ressort que les activités convective et pluvieuse au cours de ces saisons sont régies par trois modes principaux de variabilité assez proches. Au cours de ces deux saisons, les systèmes individuels générateurs de pluie se déplacent d'est en ouest, et leur activité est régulée par des enveloppes convectives se déplaçant vers l'est. Des analyses spécifiques ont mis en lumière la forte empreinte de signaux équatoriaux de type onde de Kelvin se propageant vers l'est et dont les phases régulent l'organisation des systèmes convectifs. L'impact relatif d'ondes équatoriales se propageant vers l'ouest (Rossby en particulier) et celui d'advections de masses d'air méditerranéennes n'est pas à négliger, d'autant plus qu'elles sont susceptibles d'interagir avec les ondes de Kelvin, et donc de moduler les phases de l'activité convective. Les forçages externes ainsi identités constituent des sources potentielles de prévisibilité pour les modes intrasaisonniers mis en évidence. Utilisant les données de la base multi-modèle TIGGE, l'analyse de la prévisibilité de chacun des modes principaux de variabilité est réalisée. Se focalisant sur les phases spécifiques de ces modes, les scores obtenus augurent une prévisibilité au delà de 10 jours surtout pour des prévisions initialisées lorsque les principales sources sont actives. / In this study we document the intraseasonal variability of the tropical convection and its predictability during the rainy season over the Central Africa and the Gulf of Guinea. Here, our study mainly focuses on seasons of the year for which the ITCZ is north of the equator. Based separate studies carried out on March to June and September to November seasons, we are able to identify three main modes of variability that modulate tropical convection and rainfall in West and Central Africa. During these two seasons, while individual rain-producing systems move westward, their activity is highly modulated by eastward propagating subregional and regional scale systems. Results of detailed analysis indicate the coupling between tropical convection and equatorial Kelvin wave in the region. The phases of these eastward propagating signals play an important role by regulating the organization of convective systems. Moreover, the role played by westward propagating signals (Rossby wave in particular) and Mediterranean air intrusion needs to be taken into account. These systems by interacting with Kelvin wave, may modulate the phases of convective activity in the region. Therefore, external forcing associated with these systems can be useful to the predictability of the intraseasonal modes the region. A multi model diagnostic study is performed using data available from the TIGGE project in order to evaluate the predictability of each of the main modes of variability. For a typical phase of these modes, there seems to be a statistically significant skill associated with predictability of beyond 10 days, especially for predictions initiated from active main sources.