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Les élèves officiers de marine à la fin du Premier Empire et leur destin / The students navy officers of the First Empire and their futureVencent, Hélène 06 September 2016 (has links)
Les écoles spéciales de marine (Brest et Toulon) sont créées par le décret du 27 septembre 1810 par Napoléon et son ministre de la marine Decrès. Après une période révolutionnaire qui fragilise le corps des officiers de marine, cette création s’inscrit dans la réforme du système éducatif de l’empire mais aussi dans la tradition de la formation de l’officier de marine en France. Seulement ces écoles spéciales sont fermées dès la Restauration : seule une génération d’officier a été formée, et seul un tiers de ces élèves est conservé dans la marine. L’étude de leur carrière nous montre que malgré l’épuration de la marine à la Restauration, l’ambition élitiste de Napoléon est conservée et poursuivie à travers les élèves qui parviennent à demeurer dans la marine. La deuxième partie porte alors sur les missions de la marine à travers les yeux et les actions de ces officiers. Ces derniers se démarquent par une véritable vitalité dans les projets et études scientifiques menés, mais aussi à travers les opérations militaires qui marquent l’époque. Cette étude nous montre aussi des hommes qui sont à la fois un lien entre la France métropolitaine et les territoires extra européens par leur métier, et savent s’adapter aux conjonctures politiques de leur époque : politique intérieure et politique extérieure. Une approche plus individuelle est particulièrement développée dans une troisième partie à travers leur vie de famille, l’aspect sanitaire de ce métier très exigeant pour la santé et les rapports que ces officiers entretiennent avec les autorités politiques et la hiérarchie militaire. / The Navy « Écoles spéciales » (in Brest and Toulon) were created by a bill on Septembre 27th 1810 by Napoleon and his minister of Navy, Decrès. The revolutionary era had weakened the Naval officers corps ; therefore, this decision fit into the larger education reforms by Napoleon but calls back as well to the traditional schooling of Naval officers. But those schools were shut down during the Restauration : Only one generation of officers benefited from these schools and one third of those officers remained in the Navy. Studying their career shows that, in spite of the Navy being purged during the Restauration, Napoleon’s ambition to create an elite was kept alive by those alumni who managed to stay in the Navy. The second part tackles the key objectives of the Navy as seen through the eyes and actions of these officers. These men stand out through the energy they deploy in scientific endeavours and studies, but also through their service in the military operations of the time. This study shines a light on men who, thanks to their chosen profession, are a bridge between France and oversea territories, and know how to navigate the changing politics of their time, both domestically and overseas. Thanks to their logs and reports, we can also take a closer look at the men under the uniform, studying in a third part their family life, the health aspects of their profession and the relationship those officers have with civilian authorities and their hierarchy.
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Large-scale Runoff Generation and Routing : Efficient Parameterisation using High-resolution Topography and Hydrography / Storskalig modellering av flödessvarstid ochavrinningsbildning : Effektiv parametrisering baserad på högupplöst topografi och hydrografiGong, Lebing January 2010 (has links)
Water has always had a controlling influence on the earth’s evolution. Understanding and modelling the large-scale hydrological cycle is important for climate prediction and water-resources studies. In recent years large-scale hydrological models, including the WASMOD-M evaluated in the thesis, have increasingly become a main assessment tool for global water resources. The monthly version of WASMOD-M, the starting point of the thesis, revealed restraints imposed by limited hydrological and climate data quality and the need to reduce model-structure uncertainties. The model simulated the global water balance with a small volume error but was less successful in capturing the dynamics. In the last years, global high-quality, high-resolution topographies and hydrographies have become available. The main thrust of the thesis was the development of a daily WASMOD-M making use of these data to better capture the global water dynamics and to parameterise local non-linear processes into the large-scale model. Scale independency, parsimonious model structure, and computational efficiency were main concerns throughout the model development. A new scale-independent routing algorithm, named NRF for network-response function, using two aggregated high-resolution hydrographies, HYDRO1k and HydroSHEDS, was developed and tested in three river basins with different climates in China and North America. The algorithm preserves the spatially distributed time-delay information in the form of simple network-response functions for any low-resolution grid cell in a large-scale hydrological model. A distributed runoff-generation algorithm, named TRG for topography-derived runoff generation, was developed to represent the highly non-linear process at large scales. The algorithm, when inserted into the daily WASMOD-M and tested in same three basins, led to the same or a slightly improved performance compared to a one-layer VIC model, with one parameter less to be calibrated. The TRG algorithm also offered a more realistic spatial pattern for runoff generation. The thesis identified significant improvements in model performance when 1) local instead of global climate data were used, and 2) when the scale-independent NRF routing algorithm was used instead of a traditional storage-based routing algorithm. In the same time, spatial resolution of climate input and choice of high-resolution hydrography have secondary effects on model performance. Two high-resolution topographies and hydrographies were used and compared, and new techniques were developed to aggregate their information for use at large scales. The advantages and numerical efficiency of feeding high-resolution information into low-resolution global models were highlighted. / Vatten har alltid varit en nyckelfaktor för jordens utveckling. Att förstå och kunna modellera det storskaliga vattenkretsloppet är betydelsefullt såväl för klimatförutsägelser som för studier av vattenresurser. På senare år har storskaliga hydrologiska modeller, däribland WASMOD-M som utvärderas i denna avhandling, i ökande utsträckning kommit att användas som huvudverktyg för utvärdering av globala vattenresurser. Den månatliga versionen av WASMOD-M, avhandlingens startpunkt, användes för att påvisa inskränkningar som låg i begränsande hydrologi- och klimatdata liksom behovet av att minska modellens strukturella osäkerheter. Modellen simulerade den globala vattenbalansen med ett mycket litet volymfel (avrinningens långtidsmedelvärde) men var mindre lyckosam att efterlikna dynamiken. Under senare tid har globala topografiska och hydrografiska data med hög rumslig upplösning och kvalitet blivit tillgängliga. Avhandlingens huvudsakliga drivkraft var att utveckla WASMOD-M med hjälp av dessa data i syfte att bättre fånga den globala vattendynamiken och för att parametrisera lokala ickelinjära processer i den storskaliga modellen. Under hela modellutvecklingen har skaloberoende, lågparametriserad modellstruktur och numerisk beräkningseffektivitet varit viktiga bivillkor. En ny skaloberoende svarstidsalgoritm, benämnd NRF (network-response function), som utnyttjar två aggregerade högupplösta hydrografier, HYDRO1k och HydroSHEDS, utvecklades och provades i tre avrinningsområden med olika klimat i Kina och Nordamerika. Algoritmen bevarar den rumsligt fördelade informationen om koncentrationstider i form av enkla responsfunktioner för vattendragsnätet för godtyckliga lågupplösta beräkningsrutor in en storskalig hydrologisk modell. En distribuerad algoritm för avrinningsbildning, benämnd TRG (topography-derived runoff generation), utvecklades för att representera den höggradigt ickelinjära processen i större skalor. Algoritmen användes i den dagliga WASMOD-M och provades i samma tre avrinningsområden som ovan. Modellprestanda blev lika bra eller bättre än en enlagers VIC-modell fast med en parameter mindre att kalibrera. TRG-algoritmen gav ett rimligare rumsligt mönster för avrinningsbildningen. Avhandlingen har identifierat påtagliga förbättringar i modellprestanda när 1) lokala i stället för globala klimatdata användes och 2) när NRF, den skaloberoende svarstidsalgoritmen användes i stället för en traditionell magasinsbaserad svarstidsalgoritm. Samtidigt har klimatdatas rumsliga upplösning och val av högupplöst hydrografi en andra ordningens inverkan på modellprestanda. Två högupplösta topografier och hydrografier användes och jämfördes, och nya tekniker utvecklades för att aggregera deras informationsinnehåll i stora skalor. Fördelarna och den numeriska beräkningseffektiviteten av högupplöst information i lågupplösta globala modeller har belysts.
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An Ocean General Circulation Model Study Of The Arabian Sea Mini Warm PoolKurian, Jaison 09 1900 (has links)
The most important component of the climate system over the Indian Ocean region is the southwest monsoon, which dictates the life and economy of billions of people in the tropics. Being a phenomena that involves interaction between atmosphere, ocean and land, the southwest monsoon is strongly influenced by upper ocean, primarily through warm sea surface temperature (SST). This is particularly true about the southeastern Arabian Sea (SEAS) and the onset of southwest monsoon over the peninsular India. A localized patch of warm water, known as the Arabian Sea mini warm pool (ASMWP), forms in the SEAS during February–March. It remain as the warmest spot in the northern Indian Ocean till early April. A large region, surrounding the SEAS, attains SST exceeding 30°C during April–May, with often the ASMWP as its core. The ASMWP is believed to have a critical impact on the air-sea interaction during the onset phase of southwest monsoon and on the formation of the onset vortex, during late May or early June. This thesis addresses the formation mechanisms of ASMWP, using a high-resolution Ocean General Circulation Model (OGCM) of the Indian Ocean.
In addition to the formation of ASMWP, the SEAS is characterized by several features in its hydrography and circulation, which have been invoked in the past to explain the preferential warming of this oceanic region. During November–January, the prevailing surface currents transport low-salinity water from the Bay of Bengal into the SEAS and leads to strong haline stratification in the upper layer and formation of barrier layer (layer between mixed layer and isothermal layer). The vertical distribution of temperature in the SEAS exhibit inversions (higher subsurface temperature than that at surface) during December–February. A high in sea level and anticyclonic eddies develop in the SEAS during December and they propagate westward. These eddies modify the hydrography through downwelling and play an important role in the redistribution of advected low-salinity water within the SEAS. The seasonally reversing coastal and equatorial currents present in and around SEAS also have a major contribution in setting up the hydrography, through the advection and redistribution of cooler low-salinity water. These features make the SEAS a unique oceanographic region.
The first hypothesis on the formation of ASMWP, which has been suggested by diagnostic studies, is based on the barrier layer mechanism. The barrier layer, caused by the influx of low-salinity water at surface, is argued to maintain a shallow mixed layer which can warm more efficiently. In addition, presence of barrier layer can prevent mixed layer cooling, by cutting off the interaction of mixed layer with cooler thermocline water below. However, a coupled model study have shown that there is no significant impact on the ASMWP formation from barrier layer, but only a weak warming effect during it mature phase during April. The second hypothesis, which is based on an OGCM study, has suggested that the temperature inversions present within the barrier layer can heat the mixed layer through turbulent entrainment and in turn lead to the formation of ASMWP during February–March. Both hypotheses rule out the possibility of air-sea heat fluxes being the primary reason in its formation.
The strong salinity stratification in the SEAS during December–March is central to the hypotheses about formation of the ASMWP. Observational studies have only limited success in assessing the contribution from barrier layer and temperature inversions, as the ASMWP always form in their presence. OGCMs offer a better alternative. However, modelling processes in the northern Indian Ocean, especially that in the SEAS, is a challenging problem. Previous Indian Ocean models have had serious difficulties in simulating the low-salinity water in the Bay of Bengal and its intrusion into the SEAS. The northward advection of low-salinity water in the SEAS, along the west coast of India, is used to be absent in model simulations. Moreover, the coarse resolution inhibited those models from simulating faster surface currents and vigorous eddies as seen in the observations.
In this thesis, we use an OGCM of the Indian Ocean, based on the recent version of Modular Ocean Model (MOM4p0), to study the ASMWP. The model has high resolutions in the horizontal (1/4o x 1/4o) and vertical (40 levels, with 5 m spacing in upper 60 m), and has been forced with daily values momentum, heat and freshwater fluxes. The turbulent (latent and sensible) and long wave heat fluxes have been calculated as a function of model SST. The freshwater forcing consists of precipitation, evaporation and river runoff, and there are no surface restoring or flux adjustments. The river runoff has been distributed over several grid points about the river mouth instead of discharging into a singe grid point, which has resulted in remarkable improvements in salinity simulation.
The model simulates the Indian Ocean temperature, salinity and circulation remarkably well. The pattern of model temperature distribution and evolution matches very well with that in the observations. Significant improvements have been made in the salinity simulation, including the Bay of Bengal freshwater plume and intrusion of low-salinity water from the bay into the SEAS. The salinity distribution within the SEAS is also well represented in the model. The use of appropriate horizontal friction parameters has resulted in the simulation of realistic currents. The observed features in the SEAS, including the life cycle of the ASMWP, low-salinity water, barrier layer, temperature inversions, eddies and currents are well represented in the model.
Present study has unraveled the processes involved in the life cycle of barrier layer and temperature inversions in the SEAS. Presence of low-salinity water is necessary for their formation. Barrier layer develops in the SEAS during November, after the intrusion of low-salinity water from the Bay of Bengal. The barrier layer is thickest during January–February, and it dissipates during March–April. The variations and peak of barrier layer thickness is controlled by variations in isothermal layer depth, which in turn is dominated by the downwelling effects of anticyclonic eddies. The intense solar heating during March–April leads to the formation of shallow isothermal layer and results in the dissipation of barrier layer. Temperature inversions starts developing in the SEAS during December, reaches its peak during January–February and dissipates in the following months. Advection of cooler low-salinity water over warmer salty water and penetrating shortwave radiation is found to cause temperature inversions within the SEAS, whereas winter cooling is also important to the north and south of the SEAS. There is significant variation in the magnitude, depth of occurrence and formation mechanisms of temperature inversions within the SEAS.
Analysis of model mixed layer heat budget has shown that the SEAS SST is mainly controlled by atmospheric forcing, including the life cycle of ASMWP. It has also shown that the heating from temperature inversions do not contribute to the formation of ASMWP. In an experiment in which a constant salinity of 35 psu was maintained over the entire model domain, the ASMWP evolved very similar to that in the standard run, suggesting that the salinity effects are not necessary for the formation of ASMWP. Examination of wind field show that the winds over the SEAS during November–February are low due to the blocking of northeasterly winds by Western Ghats. Several process experiments by modifying the wind and turbulent heat fluxforcing fields have shown that these low winds lead to the formation of ASMWP in the SEAS during February–March. The low winds reduce latent heat loss, resulting in net heat gain by the ocean. This helps the SEAS to keep warmer SST while the surrounding region experience intense cooling under the strong dry northeasterly winds. As the winds are weak over the SEAS, the mixed layer is not able to feel the stratification beneath and the mixed layer depth is determined by solar heating, with or without salinity effects. In addition, the weak winds are not able to entrain the temperature inversions present in the barrier layer. The winds are weak during March–April too, and the air-sea heat fluxes dictate the SST evolution during this period. Therefore, during November–April, the SEAS acts as a low wind heat-dominated regime, where the evolution of sea surface temperature is solely determined by atmospheric forcing. We show that, in such regions, the evolution of surface layer temperature is not dependent on the characteristics of subsurface ocean, including the presence of barrier layer and temperature inversions.
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Análise morfométrica e biodiversidade da vegetação na microbacia hidrográfica da Fazenda Experimental Edgárdia /Moreira, Lilian, 1976- January 2007 (has links)
Orientador: Valdemir Antonio Rodrigues / Banca: Antônio de Pádua Sousa / Banca: Luiza Helena Duenhas / Abstract: The preservation of the biodiversity of the vegetation in the micro watershed is of basic importance for the maintenance of the animal and vegetal wild life, ambient services and protection of the biosfera. The morphometry is a tool of great importance as diagnostic of susceptibility to the ambient degradation or conservation and guides the planning and handling of the micro watershed. The present study had as objective the morphometric characterization and analysis of biodiversity in the micro watershed of the Edgárdia Farm, Botucatu - SP. The micro watershed of the Edgárdia Farm belongs to the College of Agronomicas Ciencias/UNESP, city of Botucatu - SP. The program used for the attainment of the morphometrical variable was the ILWIS 3.2 version and the topographical letter of the IBGE with 1:50.000 scale. In the study of biodiversity four transects in the micro watershed had been installed, in the parts high (superior third), medium high and medium low (medium third) and low (inferior third) of the micro watershed, in which parcels of 10 x 5 meters had been installed. In the four transects, the forest species had been quantified and commanded in popular and classified families, species, names in its respective ecological successions (pioneer, secondary or climax). It was measured in each tree the height and the diameter in the height of the chest (DAP). The morphometrical variable and the results were: area of 7,205 kmø; perimeter of 11,59 km; length and width of micro watershed 3,578 the equal 3,016 km; length of the draining net and quotas of 15,68 km and 1100,00 km; factor of form 0,79, considered very high; density of draining of 2,18 km.kmø, classified as average; the high declivity of 76,98%, in accordance with the classes of declivities and types of relief of the micro watershed, was classified as scarped; frequency of rivers the 3,19 segments of rivers... (Complete abstract click electronic access below) / Mestre
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Approaches to Empire: Hydrographic Knowledge and British State Activity in Northeastern North America, 1711-1783Marsters, Roger Sidney 07 December 2012 (has links)
This dissertation studies the intersection of knowledge, culture, and power in contested coastal and estuarine space in eighteenth-century northeastern North America. It examines the interdependence of vernacular pilot knowledge and directed hydrographic survey, their integration into practices of warfare and governance, and roles in assimilating American space to metropolitan scientific and aesthetic discourses. It argues that the embodied skill and local knowledge of colonial and Aboriginal peoples served vital and underappreciated roles in Great Britain’s extension of overseas activity and interest, of maritime empire. It examines the maritimicity of empire: empire as adaptation to marine environments through which it conducted political influence and commercial endeavour. The materiality of maritime empire—its reliance on patterns of wind and current, on climate and weather, on local relations of sea to land, on proximity of spaces and resources to oceanic circuits—framed and delimited transnational flows of commerce and state power. This was especially so in coastal and riverine littoral spaces of northeastern North America. In this local Atlantic, pilot knowledge—and its systematization in marine cartography through hydrographic survey—adapted processes of empire to the materiality of the maritime, and especially to the littoral, environment. Eighteenth-century British state agents acting in northeastern North America—in Mi’kmaqi/Acadia/Nova Scotia, Newfoundland and Labrador, Quebec, and New England—developed new means of adapting this knowledge to the tasks of maritime empire, creating potent tools with which to extend Britain’s imperial power and influence amphibiously in the eighteenth and nineteenth centuries. If the open Atlantic became a maritime highway in this period, traversed with increasing frequency and ease, inshore waters remained dangerous bypaths, subject to geographical and meteorological hazards that checked overseas commercial exchange and the military and administrative processes that constituted maritime empire. While patterns of oceanic circulation permitted extension of these activities globally in the early modern period, the complex interrelation of marine and terrestrial geography and climate in coastal and estuarine waters long set limits on maritime imperial activity. This dissertation examines the nature of these limits, and the means that eighteenth-century British commercial and imperial actors developed to overcome them.
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Postglazialer Anstieg des Meeresspiegels, Paläoklima und Hydrographie, aufgezeichnet in Sedimenten der Bermuda inshore waters / Postglacial rise of sea level, palaeoclimate and hydrography, recorded in sediments of the Bermuda inshore watersVollbrecht, Rüdiger Dr. 13 January 1997 (has links)
No description available.
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Oceanographic Considerations for the Management and Protection of Surfing BreaksScarfe, Bradley Edward January 2008 (has links)
Although the physical characteristics of surfing breaks are well described in the literature, there is little specific research on surfing and coastal management. Such research is required because coastal engineering has had significant impacts to surfing breaks, both positive and negative. Strategic planning and environmental impact assessment methods, a central tenet of integrated coastal zone management (ICZM), are recommended by this thesis to maximise surfing amenities. The research reported here identifies key oceanographic considerations required for ICZM around surfing breaks including: surfing wave parameters; surfing break components; relationship between surfer skill, surfing manoeuvre type and wave parameters; wind effects on waves; currents; geomorphic surfing break categorisation; beach-state and morphology; and offshore wave transformations. Key coastal activities that can have impacts to surfing breaks are identified. Environmental data types to consider during coastal studies around surfing breaks are presented and geographic information systems (GIS) are used to manage and interpret such information. To monitor surfing breaks, a shallow water multibeam echo sounding system was utilised and a RTK GPS water level correction and hydrographic GIS methodology developed. Including surfing in coastal management requires coastal engineering solutions that incorporate surfing. As an example, the efficacy of the artificial surfing reef (ASR) at Mount Maunganui, New Zealand, was evaluated. GIS, multibeam echo soundings, oceanographic measurements, photography, and wave modelling were all applied to monitor sea floor morphology around the reef. Results showed that the beach-state has more cellular circulation since the reef was installed, and a groin effect on the offshore bar was caused by the structure within the monitoring period, trapping sediment updrift and eroding sediment downdrift. No identifiable shoreline salient was observed. Landward of the reef, a scour hole ~3 times the surface area of the reef has formed. The current literature on ASRs has primarily focused on reef shape and its role in creating surfing waves. However, this study suggests that impacts to the offshore bar, beach-state, scour hole and surf zone hydrodynamics should all be included in future surfing reef designs. More real world reef studies, including ongoing monitoring of existing surfing reefs are required to validate theoretical concepts in the published literature.
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