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Cette thèse correspond à une étude comparative détaillée de trois gisements aurifères birimiens (~ 2 Ga) du craton ouest africain (Syama, Tabakoroni et Tellem), situés sur la ceinture de Bagoé au Mali. La minéralisation se concentre dans les roches où les structures de déformation fragile sont les plus développées (basaltes et métasédiments bréchifiés, microgranite à Tellem) et se développe préférentiellement en bordure des veines. Les sulfures majeurs (pyrite à Syama et pyrite + arsénopyrite à Tabakoroni et Tellem) sont zonés avec : i) un cœur arsénifère riche en inclusions d'albite, d'ankérite et de rutile (accessoirement pyrrhotite); ii) une bordure limpide, globalement moins arsénifère que le coeur mais présentant une fine zonation avec des alternances de zones riches en As et de zones pauvres en As. L'or se présente sous forme d'or invisible inclus dans le réseau cristallin des sulfures, de petits grains individualisés en inclusion dans les sulfures, souvent accompagnés de sulfoantimoniures, notamment la tétraédrite et la chalcostibite, et d'or libre associé au quartz. Les pyrites arsénifères et les arsénopyrites des gisements de la ceinture de Bagoé sont parmi les plus riches en or invisible de tous les gisements d'or de l'Afrique de l'Ouest et tout à fait comparables à ceux de la ceinture d'Ashanti au Ghana. / This thesis presents a comparative study of the Syama, Tabakoroni and Tellem gold deposits, located in the N-S trending Bagoé greenstone belt of Mali. Mineralization is found preferentially along the edges of millimetre- to centimetre-sized quartz, quartz-albite, quartz-ankerite, dolomite-quartz veins developed in tension gaps that formed during brittle deformation. Gold mineralization is mostly associated with pyrite in the three deposits, and also with arsenopyrite at Tabakoroni and Tellem. These sulphides are zoned with (i) an arsenic-rich core containing several albite, ankerite and rutile inclusions (less commonly, pyrrhotite) and (ii) a clear border of finely alternating As-rich and As-poor bands. Gold occurs in the form of i) invisible gold included in their crystal lattices, ii) small individual grains bound to these sulphides, frequently accompanied by sulphoantimonides, mainly tetrahedrite and chalcostibite and iii) free gold associated with quartz. The arseniferous pyrites and arsenopyrites of the Bagoé belt deposits are among the richest in invisible gold in all gold deposits in West Africa and are quite comparable to those of the Ashanti Belt in Ghana.

Cette thèse s'intéresse à un segment de croûte d'âge Paléoprotérozoïque du craton ouest-africain. Les roches de la zone d'étude comprennent des roches volcaniques et volcanoclastiques mafiques à felsiques, des paragneiss de haut grade métamorphique et des ensembles volcano-sédimentaires faiblement métamorphisés. De nouvelles cartes lithologiques, métamorphiques et structurales sont construites à l'aide d'une approche intégrée, couplant cartographie de terrain et interprétation des données géophysiques aéroportées à l'échelle régionale. L'analyse des données géochimiques et géochronologiques des suites magmatiques de la ceinture de roches vertes de Sefwi révèle une affinité marquée avec le magmatisme calco- alcalin, produit des arcs volcaniques modernes et avec les TTGs d'âge Néoarchéen, impliquant une certaine diversité des sources et des processus pétrogénétiques. Des coeurs de zircons hérités, présents au sein de la suite magmatique livrent des âges autour de ca. 2250 à 2270 Ma. Leurs couronnes révèlent des âges de mise en place compris entre ca. 2189 et 2081 Ma. L'analyses Lu-Hf sur zircon livre des valeurs eHf positives et des âges modèles pour la croûtes situés entre 2650 et 2250 Ma. Ces valeurs indiquent l'existence d'une proto-croûte à tendance radiogènique et des temps de séjour limités pour ces magmas évoluant au sein de cette proto-croûte. L'évolution des magmas montre qu'ils ont été générés de façon concomitante, vers 2155 Ma, certains dérivants de la fusion d'une source mafique faiblement enrichit en potassium et formant des magmas sodiques, riches en silice, de type TTGs, d'autres de composition plus dioritiques, générés à partir de la fusion du manteau métasomatisé et enrichit en LILE. La mise en place plus tard vers ca. 2136 Ma de monzonites, présentant de teneurs élevées en potassium, soutient l'hypothèse d'une interaction avec des magmas de refusion de TTG existants au sein de la croûte. Le dernier stade du magmatisme est caractérisé par la mise en place de granites à deux micas et de leucogranites, le long de la marge nord-ouest de la ceinture de roches vertes vers ca. 2092 et 2081 Ma, marquant le stade de la collision au sein de l'orogène Eburnéenne. L'évènement tectono-métamorphique d'âge Eburnéen est caractérisé par un métamorphisme initialement de faciès amphibolite de haute pression, associé à un gradient géothermique assez froid (HP-MT, ~ 15-17 ° C / km). Le raccourcissement D1, orienté NNO-SSE, a généré une foliation pénétrative (S1), parallèle au litage des roches et des plans de chevauchement à tendance décrochant, orienté E-W. Cette tectonique précoce a provoquée l'enfouissement de roches supra-crustales (sédiments, roches volcaniques) et un épaississement de la croûte. Cet évènement métamorphique précoce évolue dans le temps et l'espace vers le facies amphibolite-granulite et l'anatexie. Les données SHRIMP U-Pb in-situ sur monazite livré des âges autour de ca. 2073 Ma. Ces monazites sont présentes au sein de paragénèses métamorphiques (D2) soulignant la foliation S2. Ces âges sont interprétés comme marquant le début de l'exhumation et du refroidissement de la croûte inférieure. Des détachements normaux, orientés NNE-SSO et des structures constrictives se sont formés conjointement au sein d'un régime de déformation D2 globalement transtensif, à jeux sénestre. Un régime compressif plus tardif (D3) a ensuite causé une réactivation en mouvement dextre de ces structures cisaillantes orientées NE-SO avec une rétrogression en schistes verts. Nous proposons que les segments de croute juvénile ont été générés en contexte d'arc intra-océanique, associé à un magmatisme intense et varié, issus des processus de subduction qui prendront fin lors des stades d'accrétion et de collision de ces segments d'autres terranes birimiens. La marge nord-ouest de la ceinture de roches vertes de Sefwi est interprétée comme une zone de suture entre des segments d'arc originellement séparés. / This thesis investigates the Palaeoproterozoic crust of the West African Craton in southwest Ghana, providing insight into its controversial geodynamic and tectonic evolution. Rocks of the study area comprise greenschist- to amphibolite facies, mafic to felsic volcanic and volcaniclastic rocks, high-grade paragneisses and low-grade volcano-sedimentary packages, all of which are extensively intruded by multiple generations of granitoids. New lithological, metamorphic and structural maps are constructed using integrated field mapping and interpretation of regional airborne geophysical datasets. This approach is used to constrain the deformation history of the sparsely exposed rocks of the NE- to NNE-striking Sefwi Greenstone Belt and the adjacent volcano-sedimentary domains deformed during the Eburnean Orogeny (2150-2070 Ma). Combined geochemical and geochronological analysis of the magmatic suites of the Sefwi Greenstone Belt reveal calc-alkaline, volcanic arc affinities, as well as a striking similarity to Neoarchean TTGs that require diverse magma sources and petrogenetic processes. Rare inherited zircon cores from the Palaeoproterozoic magmatic suite yield ages of ca. 2250 to 2270 Ma, with granitoid emplacement ages ranging between ca. 2189 and 2081 Ma. Zircon Lu-Hf analysis reveals consistently positive eHf(t) values and two-stage crustal model ages between 2650 and 2250 Ma, indicative of a radiogenic proto-crust and short crustal residence times. The magmatic evolution reveals the coeval generation of sodic, high-silica TTGs derived from partial melting of low-K mafic sources and dioritic magmas generated in a metasomatised, LILE-enriched mantle wedge at ca. 2155 Ma. Subsequent emplacement of high-K quartz monzonites at ca. 2136 Ma supports the interaction of mantle-derived magmas and remelting of existing TTGs. The final stage of magmatism is characterised by the emplacement of two-mica-granites and leucogranites along the NW margin of the Sefwi Greenstone Belt between ca. 2092 and 2081 Ma, interpreted as a terminal collisional event during the Eburnean Orogeny. Eburnean metamorphism and deformation is characterised in the study area by initial high-pressure amphibolite facies metamorphism corresponding with low apparent geothermal gradients (HP-MT, ~15-17°C/km). D1 NNW-SSE shortening generated a ubiquitous bedding-parallel foliation (S1) and ~E-W striking thrust faults, resulting in the burial of supracrustal rocks and crustal thickening. In the high-grade terrane, subsequent amphibolite-granulite facies metamorphism is associated with anatexis. In-situ SHRIMP U-Pb monazite ages at ca. 2073 Ma, hosted within, D2 mineral assemblages, are interpreted as the initial timing of cooling and exhumation, significantly later than paroxysmal metamorphism in NW Ghana and central Ivory Coast (2150-2130 Ma). NNE-striking normal detachments and constrictional deformation structures formed during sinistral ENW-WSW transtension (D2), during which segments of the middle- and lower crust were juxtaposed with low-grade domains. Subsequent E-W directed shortening (D3) caused the dextral re- activation of NE-SW striking shear zones, associated with a localised greenschist facies metamorphic overprint. We propose that the juvenile crust of southwest Ghana was generated in an intra-oceanic arc setting, associated with diverse and intense subduction-related magmatism until subsequent terrane accretion and collision. The north-western margin of the Sefwi Greenstone Belt in interpreted as a suture between the separate arc terranes, diachronously accreted during the Eburnean Orogeny. The Palaeoproterozoic crust of the southern portion of the West African Craton represents a juvenile crustal growth event, recording the unique geodynamic and orogenic processes associated with nascent subduction-related plate tectonics in the early Earth.

The present study was designed to investigate the social construction of racial and ethnic identities and categories among second-generation Canadian youth who identify as, or can be physically identified as Black. A culturally diverse sample of 34 participants aged 13 – 19 years was recruited from communities in the General Toronto Area to participate in six discussion groups. Discourse analysis was utilized to demonstrate the fluidity and negotiability of racial and ethnic identity, and the role of the immediate and wider social contexts in the constructions of these identities and the content of their associated social categories. Results are discussed with regards to the implications of the reliance on mainstream social-cognitive approaches that do not adequately address the social construction of these phenomena.

Water resources management in the Sahel region of West Africa is extremely difficult because of high inter-annual rainfall variability as well as a general reduction of water availability in the region. Observed changes in streamflow directly disturb key socioeconomic activities such as the agriculture sector, which constitutes one of the main survival pillars of the West African population. Seasonal rainfall forecasting is considered as one possible way to increase resilience to climate variability by providing information in advance about the amount of rainfall expected in each upcoming rainy season. Moreover, the availability of reliable information about streamflow magnitude a few months before a rainy season will immensely benefit water users who want to plan their activities. However, since the 90s, several studies have attempted to evaluate the predictability of Sahelian weather characteristics and develop seasonal rainfall and streamflow forecast models to help stakeholders take better decisions. Unfortunately, two decades later, forecasting is still difficult, and forecasts have a limited value for decision-making. It is believed that the low performance in seasonal forecasting is due to the limits of commonly used predictors and forecast approaches for this region. In this study, new seasonal forecasting approaches are developed and new predictors tested in an attempt to predict the seasonal rainfall over the Sirba watershed located in between Niger and Burkina Faso, in West Africa. Using combined statistical methods, a pool of 84 predictors with physical links with the West African monsoon and its dynamics were selected, with their optimal lag times. They were first reduced through screening using linear correlation with satellite rainfall over West Africa. Correlation analysis and principal component analysis were used to keep the most predictive principal components. Linear regression was used to get synthetic forecasts, and the model was assessed to rank the tested predictors. The three best predictors, air temperature (from Pacific Tropical North), sea level pressure (from Atlantic Tropical South) and relative humidity (from Mediterranean East) were retained and tested as inputs for seasonal rainfall forecasting models. In this thesis it has been chosen to depart from the stationarity and linearity assumptions used in most seasonal forecasting methods: 1. Two probabilistic non-stationary methods based on change point detection were developed and tested. Each method uses one of the three best predictors. Model M1 allows for changes in model parameters according to annual rainfall magnitude, while M2 allows for changes in model parameters with time. M1 and M2 were compared to the classical linear model with constant parameters (M3) and to the linear model with climatology (M4). The model allowing changes in the predictand-predictor relationship according to rainfall amplitude (M1) and using AirTemp as a predictor was the best model for seasonal rainfall forecasting in the study area. 2. Non-linear models including regression trees, feed-forward neural networks and non-linear principal component analysis were implemented and tested to forecast seasonal rainfall using the same predictors. Forecast performances were compared using coefficients of determination, Nash-Sutcliffe coefficients and hit rate scores. Non-linear principal component analysis was the best non-linear model (R2: 0.46; Nash: 0.45; HIT: 60.7), while the feed-forward neural networks and regression tree models performed poorly. All the developed rainfall forecasting methods were subsequently used to forecast seasonal annual mean streamflow and maximum monthly streamflow by introducing the rainfall forecasted in a SWAT model of the Sirba watershed, and the results are summarized as follows: 1. Non-stationary models: Models M1 and M2 were compared to models M3 and M4, and the results revealed that model M3 using RHUM as a predictor at a lag time of 8 months was the best method for seasonal annual mean streamflow forecasting, whereas model M1 using air temperature as a predictor at a lag time of 4 months was the best model to predict maximum monthly streamflow in the Sirba watershed. Moreover, the calibrated SWAT model achieved a NASH value of 0.83. 2. Non-linear models: The seasonal rainfall obtained from the non-linear principal component analysis model was disaggregated into daily rainfall using the method of fragment, and then fed into the SWAT hydrological model to produce streamflow. This forecast was fairly acceptable, with a Nash value of 0.58. The evaluation of the level of risk associated with each seasonal forecast was carried out using a simple risk measure: the probability of overtopping of the flood protection dykes in Niamey, Niger. A HEC-RAS hydrodynamic model of the Niger River around Niamey was developed for the 1980-2014 period, and a copula analysis was used to model the dependence structure of streamflows and predict the distribution of streamflow in Niamey given the predicted streamflow on the Sirba watershed. Finally, the probabilities of overtopping of the flood protection dykes were estimated for each year in the 1980-2014 period. The findings of this study can be used as a guideline to improve the performance of seasonal forecasting in the Sahel. This research clearly confirmed the possibility of rainfall and streamflow forecasting in the Sirba watershed at a seasonal time scale using potential predictors other than sea surface temperature.

La présente étude questionne les rapports complexes de la fiction et de l’histoire, les retentissements du contexte, le poids des enjeux historiques, idéologiques, axiologiques dans l’épopée orale. Dans l’Épopée du Foûta-Djalon, la fiction narrative relie les faits réels et les faits fictifs dans un élan de construction d’une histoire mémorable où la vérité épique élève au premier plan la figure héroïque (Abdoul Rahmâne) au détriment de la figure historique (Almâmy Oumar) et où certains faits, réaménagés et réactualisés font émerger les mythes fondateurs investis de nouveaux sens. Le conflit qui opposa en 1867 Peuls et Mandingues rejaillit dans le récit sous forme d’une opposition de valeurs, que la vision épique, ambivalente, accentue au moyen d’une dualité contrastée : Peuls vs Mandingues, Musulmans vs Animistes. Du fait de sa vocation d’exaltation des valeurs fondatrices, l’épopée se distingue de l’Histoire dont elle se nourrit mais qu’elle infléchit dans le sens d’un drame qui flatte et réveille la conscience collective sans cesse invitée à relever les défis du présent. Outre le ton idyllique ou encomiastique, l’épopée prend aussi des allures satiriques en faisant une critique sans complaisance des vicissitudes et des drames de l’Afrique contemporaine (L’enfant prodige). L’analyse de la composition, de la structure et de la performance narrative révèle une esthétique fondée sur le « style formulaire », la narration épisodique et une forte « épicisation » rhétorique, couronnée par les effets de l’accompagnement musical qui agrémente l’écoute et traduit en sons les thèmes essentiels. / : This work questions the complex relationships between fiction and history, the effects of contextual background, the weight of historical, ideological, and axiological issues in oral epic. In Épopée du Foûta-Djalon, the narrative fiction links real and fictional facts in a dynamic momentum to construct a memorable story, one in which epic truth enhances the heroic figure – Abdul Rahmane – at the expense of the historical figure – Almâmy Oumar -, and one in which some facts have been rearranged and updated, and thus bring forth the founding myths which are endowed with whole new meanings in the process. The conflict which opposed Fulah and the Mandinka people in 1867 is represented in the story in the form of adversary values which the bivalent, epic vision reinforces in a set of contrasting dualities: Fulah versus the Mandinka people, Muslims versus Animists. Because it aims to exalt founding values, the epic story differs from, though is inspired by, History, the essence of which is shifted to fit a drama meant to flatter and awaken the collective conscience endlessly urged to meet today’s challenges. Apart from its idyllic and eulogistical tone, the epic also takes on satirical airs through a thorough criticism of the vicissitudes and dramas of contemporary Africa (L’enfant prodige). The analysis of the narrative composition, structure and performance reveals an aesthetics based on what is called “the formulaic style”, the episodic narrative structure and a strong rhetorics of “epicisation”. This aesthetics culminates in the effects of the musical accompaniment which embellishes the listening of this oral epic and translates the main themes into sounds.

"After their independence, African countries undertook to establish sub-regional organisations in order to join their efforts towards improving the living standard of their populations. Primarily vested with economic objectives, these sub-regional organisations, aware that economic development cannot be attained withouth peace, security and political stability, are more and more involved with political issues, especially since the 'democratic wind' of the early 1990s. It is therefore interesting to study how sub-regional integration as an external factor affects democracy domestically, that is to contemplate to what extent this sub-regional integration is contributing to the strengthening of democracy in Africa, and to research ways of enhancing this contribution. ... The study is structured into four main chapters. The introductory chapter contains the research design. The second chapter is devoted to an overview of sub-regional integration. It examines the Economic Community of West African States (ECOWAS), but without losing sight of other groupings. The third chapter analyses the way the ECOWAS is dealing with the issue of democratic consolidation. It is interested in the question of whether the ECOWAS has an express policy and whether it has set standards as regards democratic consolidation in West Africa and, if so, how effective this policy and these standards have been so far. The fourth chapter is devoted to summary, conclusion and recommendations." -- Introduction. / Thesis (LLM (Human Rights and Democratisation in Africa)) -- University of Pretoria, 2005. / http://www.chr.up.ac.za/academic_pro/llm1/dissertations.html / Centre for Human Rights / LLM

Paper title: Transition towards entrepreneurship Purpose: This paper explores and creates understanding regarding the identity transition of West Africa immigrants towards entrepreneurship. Methodology: This study applied a qualitative research method that was exploratory and descriptive in nature. Primary and secondary data were collected and used as sources of information. Primary data were obtained through multiple in-depth interviews strategy; the interviews were designed in a semi-structured format. In total, seven African immigrant entrepreneurs were respondents in this study. Secondary data utilized in this study comprised of information obtained via scientific materials and organizational websites. A convenience sampling method was determined as the appropriate method for selection of entrepreneurs’ sample that was utilized in this study. Key findings: This study found immigrant entrepreneurs to have a tendency to expose themselves to new practices and knowledge within their new environments. West Africa immigrants’ entrepreneurs are tenacious about valuable information in their new environment, they have a tendency to integrate new information to align with their previous work experiences. In the quest for channels to test business ideas acquired or perceived, immigrant entrepreneurs often try out their new ideas on a smaller scale. This study uncovered that a successful trial process tends to persuade immigrants towards entrepreneurship once an opportunity is well established. Immigrant entrepreneurs construct latent attitudes regarding potential new business prospects in order to solidify an entrepreneurial identity. Implication for practice: This study challenges the assertion made in past literatures which expressly concluded that people considered entrepreneurship as a highly professionalized occupation and stated that only few percentage of persons devotedly take the necessary steps to start a business. This study rejects the above argument by offering guidelines to anyone who may have entrepreneurial ideas or objectives but hesitates to make the identity change that is substantial to help create a transition.  Furthermore, revelations in this research showed that setting up a new business venture from scratch is conceivable, this study highlighted some extensive development processes that are essential in generating entrepreneurial identity.  Future research direction: Adequate attention and recognition have not been awarded to West African entrepreneurs in western society, and as well as in previous academic research. In western societies, people still view West African entrepreneurs as second-hand business minded traders. Hence, this study encourages upcoming academia to explore and create emphasis regarding the impact businesses owned by West Africa immigrants’ entrepreneurs produce in our today’s society. In conjunction to the above suggestion, it should be important to highlight useful channels through which our society (especially non-migrants) can support in encouraging and empowering various immigrant entrepreneurs towards growing their businesses in their various communities.

This study focuses on the role of women in African cinema – in terms of female directors working in the African film industries as well as the representation of women in African film. My research specifically focuses on francophone West African and lusophone and anglophone Southern African cinemas (in particular post-apartheid South African cinema). This research is necessary and significant because African women are underrepresented in theoretical work as well as in the practice of African cinema. The small corpus of existing theoretical and critical studies on the work of female African filmmakers clearly shows that African women succeed in producing films against tremendous odds. The emergence of female directors in Africa is an important but neglected trend which requires more dedicated research. The pioneering research of African-American film scholar Beti Ellerson is exemplary in this regard, as she has, since the early 2000s, initiated a new field of academic study entitled African Women Cinema Studies. My own research is situated within this emerging field and aims to make a contribution to it. The absence of women in public societal spheres is often regarded as an indicator of areas where societies need to change. In the same sense the socio-political and cultural advancements of women are indicators of how societies have progressed towards improved living conditions for all. Because the African woman can be viewed as doubly oppressed, firstly by Black patriarchal culture and secondly by Western colonising forces, it is essential that the liberation of African women includes an opportunity for women to verbalise and demonstrate their own vision of women’s roles for the future. The study analyses a large corpus of films through exploring notions of nationalism and post/neo-colonialism in African societies; issues related to the female body such as health, beauty and sexuality; female identity, emancipation and African feminism in the past and present; the significance of traditional cultural practices versus the consequences and effects of modernity; and the interplay between the individual and the community in urban as well as rural African societies. Female filmmakers in Africa are increasingly claiming the right to represent these issues in their own ways and to tell their own stories. The methods they choose to do this and the products of their labours are the focus of this study. Ultimately, the study attempts to formulate more complex models for the analysis of African women’s filmmaking practices, in tracing the plurality of a female aesthetics and the multiplicity of thematic approaches in African women’s filmmaking.

La variabilité intrasaisonnière de la mousson d'Afrique de l'Ouest se caractérise par une alternance de phases sèches et humides, dont les impacts pe uvent être dramatiques sur les populations locales. Cette variabilité met en jeu un grand nombre d'échelles spatiales et temporelles, rendant difficile sa compréhension, sa modélisation et sa prévision. Cette thèse propose quelques éclairages sur ces différentes thématiques. La dépression thermique saharienne est un acteur majeur de la mousson africaine. La caractérisation de sa variabilité intrasaisonnière a permis de mettre en évidence, à l'échelle de 15 jours, l'existence d'interactions entre les latitudes moyennes et l'Afrique de l'Ouest. Lors de son passage au-dessus de l'Atlantique et la Méditerranée, un train d'ondes de Rossby module les ventilations de la dépression thermique, et donc sa structure. Les anomalies de circulation, de température et d'humidité, ainsi induites sur le Sahel, pourraient alors expliquer une partie des fluctuations intrasaisonnières de la convection, notamment celles qui naissent sur l'est du Sahel, et qui se propagent ensuite vers l'ouest. L'état moyen et la variabilité intrasaisonnière de la mousson africaine restent un défi pour les modèles de climat, même pour la dernière génération, qui a participé à l'exercice d'intercomparaison CMIP3. La variabilité à haute fréquence de la convection est un élément particulièrement difficile à modéliser. Toutefois, la meilleure prise en compte de facteurs inhibant le développement de la convection pourrait être une étape importante pour améliorer la modélisation de la mousson et la prévision de ses fluctuations intrasaisonnières / The intraseasonal variability of the West African Monsoon is associated with persistent dry and wet periods over the Sahel, whose consequences can be dramatic for local populations. Its understanding, modelling and forecast still pose a challenge to the scientific community, notably because it involves a large number of space and timescales. The present study elaborates a few answers to these issues. The Saharan heat low is one of the major actors of the African monsoon. The characterization of its intraseasonal variability revealed the existence of interaction between the tropics and the extratropics, at the 15-day timescale. As it propagates eastward above the Atlantic and the Mediterranean, a Rossby wave train modulates the heat low ventilations, and thus its structure. Anomalous circulation, as well as temperature and humidity anomalies, can be induced over the Sahel, and lead to intraseasonal modulations of convection, especially to those, which originate from the Eastern Sahel, and which, then, propagate westward. Current state-of-the-art (CMIP3) climate models still have significant problems and display a wide range of skill in simulating the West African monsoon mean state and intraseasonal variability. The high frequency variability is particularly difficult to capture. However, the account for processes, which inhibit convection development, may be expected to be an important step in the improvement of the monsoon modelling and the forecast of its intraseasonal fluctuations