PHYSICAL OCEANOGRAPHY

Author: GIL COTO MIGUEL.
Year: 2003.
University: VIGO [www.uvigo.es].
Place of defense: FACULTAD DE CIENCIAS DEL MAR.
Place of preparation: FACULTAD DE CIENCIAS DEL MAR.

Summary: Models boxes have been used on many occasions to study the movement of the residual Rias Bajas, using the field termohalino (temperature and salinity) as a tracer through equations conservación.En this theory models are used as a tool boxes to study calculates the Estuary Vigo.Tras an introduction to water bodies that are distributed on the west coast of Galicia and the coastal upwelling, the process oceanographic more important than efacta to the Rias Bajas, described the secrets of the model boxes: his geotría, balances owned applying to them, parametrizations for heavy and sinks of the equations balance property, etc.Posteriormente discusses the relationship between models boxes and inverse methods and presents the model OERFIM (Optimun Estuarine Residual Fluxes with a multiparameter Inverse Metrhod), a model that combines balance sheets termohalinos with biogeochemical balances for a solution óptima.Como practical example the OERFIM applies to Estuary Vigo.A then, and for the first time, it is designed and implements a model of boxes to study the movement of the residual Ria de Vigo from a three-dimensional non-stationary and low and the requirement to obtain the mixing coefficients not negativos.Los results of the three-dimensional model is correlaacionan with different forcings of the Residual movement, to study the dynamics governing the movement residual.Finalmente also have developed the algorithms necessary to move from geographic coordinates to UTM coordinates (and vice versa) algorithms useful inthe calculating the geometric boxes and the interpolation three-dimensional used in data processing termohalinos.

Author: CRIADO ALDEANUEVA FRANCISCO.
Year: 2004.
University: MÁLAGA [www.uma.es].
Place of defense: E.T.S.I. INFORMÁTICA.
Place of preparation: UNIVERSIDAD DE MÁLAGA.

Summary: Based on data collected in the campaign GULF 2001 (divided into three subcampañas: mesoscale 1, macro and mesoscale 2), has made a study of the circulation and distribution of water bodies in the Gulf of Cadiz in the spring of 2001 , as well as the variability induced forcing weather. The bulk of the information to conduct the pilot study what form of CTD data, which are made by the geostrophic analysis in the region outside of the Gulf of Cadiz, and data ADCP, which have been used to study the movement on the shelf and continental slope. Weather conditions show that in the mesoscale 1 and most of the macro, the prevailing wind was Poniente. The mesoscale 2, was an episode of moderate lift. This variability has led to study the response of structures to forcing weather. The general circulation surface in the Gulf of Cadiz is anticyclonic with variations intercampañas. With Ponientes, flows are approaching closer to Cape Santa Maria are Levantes. Calculations geostrophic concern 300m, to maximize the flow of entrance to the Strait. The NACW is the most representative body of water in the first 1000m of the water column. In isopicna ot = 27 temperature and salinity are virtually uniform. The region lower NACW (t = 27.3) is dragged along the MW in the northern area towards the open ocean, while the top (t = 26.6) form the core of the anticyclonic circulation surface Gulf . In the region foreign reserves main NACW, the movement of this body of water is very low. The NACW emerges primarily in the areas of Cape St. Vincent and the Cape Santa Maria. The first is a process of open ocean and the second has a greater influence coastal quick response times to changing winds. With Ponientes intensifies and Levantes weakens or disappears. The waters afloradas in Cape Saint Vincent moving from west to east along the mainstream to 7.5 Â º W, where some are transported to the South or Southeast, to be the filament of Cape St. Mary, which reached its maximum signal around the 40 -50 meters. The study of mixtures surface leads to the conclusion that a change in regime wind produces a wide temporal variability of some space structures (alforamiento Cape Santa Maria, sign surface of the Front de Huelva, against coastal superficial ..) in a relatively layer somera (25 meters). The surface movement in the eastern spring platform consists of a cell of cyclonic mesoscale between Cape Santa Maria and the mouth of the Guadalquivir river. The northern part of the cell is a counterpoint that carries warm waters to the west, and reaches beyond Cape Santa Maria Levantes according to records ADCP. In the western part identifies a cyclonic swirl of great consistency in depth. The historically called Frente de Huelva would signal of a front surface thermal density in the eastern platform, which corresponds to the eastward component of the cell cyclonic East and still circulating yet in a position to lift.

Author: BOLAÑOS SANCHEZ RODOLFO.
Year: 2004.
University: POLITÉCNICA DE CATALUÑA [www.upc.edu].
Place of defense: UPC-BARCELONA.
Place of preparation: EDIFICI D1 Campus NORD.

Author: JORDA SANCHEZ GABRIEL.
Year: 2004.
University: POLITÉCNICA DE CATALUÑA [www.upc.edu].
Place of defense: SALA LECTURA PROJECTES. MÒDUL C1 CAMPUS NORD.
Place of preparation: EDIFICI D1 Campus NORD.

Summary: The goal of this thesis is to implement a data assimilation scheme into a hydrodynamic model of the catalan continental shelf. This system would allow us to combine the information provided by measured data with the information coming from the numerical models in order to find the best approach, from a statistical point of view, of reality. To reach this objective it is needed, in a first moment, to have a good knowledge of the region and of the physical processes therein. The next step is to have a numerical model able to reproduce in a realistic way the dynamics of the area. Afterwards, the error sources of the system and the error dynamics should be characterized to, finally, implement a data assimilation system well suited for the problem. Following this way we can take profit of the data available and the tools developed to deepen in the the knowledge of the dynamics in the catalan continental shelf from different approaches. -The analysis of the measures obtained in the frame of the research projects FANS and YOYO have allowed us to characterize the region dynmics, to study the origin of the slope current variability in the high and low frequencies, to study the processes over the shelf and to see the water mass evolution. -The implementation of the hydrodynamical model SYMPHONIE has been done carefully applying a new initialization technique (the modal potential vorticity method) and has been validated agains real data to obtain a complet and realistic model. Once we had this part done, we have used it to study the evolution of a topographic Rossby wave over the continental shelf, the wind effects over the 3D dynamics and the exchanges shelf-slope induced by the wind and the slope current. -The stochastic modelling has been used to describe the dynamics of the errors associated to the slope current characterization and the wind field. We have determined that the former are stationary but non linear while the last are non stationary but highly linear. From these results we have also defined the EOFs base which defines the reduced order space where the data assimilation will be carried on. -Taking profit of the above mentioned elements, we have implemented the SEQUOIA data assimilation system with an analysis kernel based in the reduced order optimal interpolation. After evaluationg its behaviour we have used a twin experiments protocol to compare the performance of different observational networks to correct different model errors. Altough all the work have been done in the frame of the catalan continental shelf, most of the obtained results and the techniques used could be applied to other shelf-slope regions with similar characteristics.

Author: LÁIZ ALONSO IRENE MARÍA.
Year: 2005.
University: LAS PALMAS DE GRAN CANARIA [www.ulpgc.es].
Place of defense: FACULTAD DE CIENCIAS DEL MAR.
Place of preparation: FACULTAD DE CIENCIAS DEL MAR.

Summary: This thesis work has been carried out along the lines of Physical Oceanography Research Group, Department of Physics at the University of Las Palmas de Gran Canaria. One of the hotbeds of interest of this group has been, traditionally, the study of the eastern branch of the recirculation flow Canary and its relationship to coastal upwelling of northwest Africa. Thus, this study arose from the need to prove the hypothesis physically link between the two systems. Analysis of movement in the coastal ocean and its influence on the circulation of the ocean interior has been undertaken by developing a simple model of ocean circulation and changing its boundary conditions on the eastern edge. Using the theory cuasigeostrófica to define equations of the model has meant the advantage of being able to translate vorticity in terms of the physical processes that give rise to new boundary conditions. In a second step, an analysis of the vorticity at the eastern edge has been extended to study the effects of the outflow of water into the Mediterranean Sea. The model has been subjected to a sensitivity analysis to the boundary conditions, which have used various combinations thereof. This has enabled the solutions more realistic, not only in terms of their adjustment to income derived from real data, but in terms of the physical sense. During this process, the model has been forced with a wind field theory. Finally, we have implemented an actual wind field to study seasonal pattern of movement associated with the wide variability basin wind field. The results have led not only corroborate the hypothesis coupling between the Canary Current and coastal upwelling, but find a reasonable justification for the aforementioned physical link.

Author: MAITANE OLABARRIETA LIZASO.
Year: 2005.
University: CANTABRIA [www.unican.es].
Place of defense: E.T.S.DE INGENIEROS DE CAMINOS, C.Y P..
Place of preparation: E.T.S. DE INGENIEROS DE CAMINOS.

Summary: The thesis entitled 'numerical modeling of the interaction ola-corriente in estuaries' has been devoted to the analysis of the effects of interaction ola- correinte place in the flow of the tide, with the ultimate goal to establish the way in which this effect should being included in the numerical models which simulate the hydrodynamic behavior of etuarios. In these coastal areas, the coexistence of waves with the current tide is a very common, yet rarely is seen as the combined effect of wave, tide and the nonlinear interaction between the two. Since the effect of the interaction ola- flow is evident from the point of view of the current, in a variation of the apparent roughness of the bed, in an amendment to the tangential surface tension and viscosity variations in horizontal swirl The thesis focuses on the analysis of how these effects must be completed in numerical models that solve the Navier Stokes equations and vertically integrated in a perido wave. To this end there is a numerical model two-dimensional 2DV, which solves the vertical structure of the flow in streams combined. The model was validated using data from laboratory desmostrándose that the results are satisfactory. To parameterize the effects of interaction ola-corriente in the vertical profile of the stream, has developed a neural network that feeds on the model results 2DV, so that the network serves to include this effect in models hidrodinámmicos . Finally, using a two-dimensional model analyzes the major implications that the interaction ola- flow causing the spread of the tidal wave over a simplified one-dimensional estuary.

Author: RUBIO COMPAÑY ANNA.
Year: 2005.
University: POLITÉCNICA DE CATALUÑA [www.upc.edu].
Place of defense: AULA C-1. 002.
Place of preparation: EDIFICI D1 Campus NORD.

Summary: Mesoscale variability in the Catalan Sea is related to the presence of anticyclonic eddies. These eddies, which are characterized by diameters of 40-50 Km, are responsible for local flow inversions over the shelf, variations in the shelf/slope exchanges and modifications in the biological activity. Historically, their origin has been related to local processes linked to the density front variability, the spatial variability of the wind field or to bathymetric effects. However, recent studies have suggested that these eddies could also be generated upstream, in the Gulf of Lions. The main objective of this thesis is to study the characteristics of these eddies as well as their origins and paths. In a first stage, the study of these eddies is carried out by means of an experimental approximation involving an oceanographic cruise in the Catalan Sea. During this oceanographic cruise, SST images are used to conduct the survey in order to characterize an isolated eddy. The joint analysis of in-situ data and the SST images gives us a 3D description of one of these anticyclonic eddies and allows us to follow its temporal evolution during the survey. Furthermore, based on previous work, the analysis of SST images suggests, as a first approximation, three hypotheses concerning the eddieâs origin and path. In a second part a numerical model is used in the NW Mediterranean in order to study of the origin of theses eddies. The validation of the model results shows that the model is able to reproduce realistically the main characteristics of the circulation as well as the generation of coherent eddies in two areas of the Gulf of Lions: Marseilles and Roussillon coasts. The model suggests that in both cases the eddy generation is linked to a flow separation mechanism. On the one hand, off the Marseilles coast, this mechanism is related to the variations in slope direction and is triggered by the Northern Current intensifications. As a result of flow separation anticyclonic eddies are generated over the slope. During their development these eddies are advected south-westwards by the Northern Current. On the other hand, off the Roussillon coast the flow separation mechanism takes place over the shelf linked to the coastal current perturbation by the Creus Cape. Flow separation is triggered by the coastal current intensifications induced by NW winds and it takes place in combination with downwelling processes over the shelf. The result of this process is the generation over the shelf of mesoscale anticyclonic eddies which are advected by the coastal current towards the slope and then by the Northern Current towards the Catalan Sea. The investigation of the generation mechanisms, characteristics and evolution of the modelled eddies allows us to check the different hypotheses proposed during the experimental work and, finally, to find out the origin and path of the anticyclone observed in the Catalan Sea.