Modelo tridimensional de camino aleatorio para un derrame de petróleo : aplicación al derrame producido por el North Cape

Doctorado en Ciencias Físicas. Programa de Oceanografía y Física aplicada.

Generation of the Cape Ghir upwelling filament: a numerical study

[EN] Filaments are narrow, shallow structures of cool water originating from the coast. They are typical features of the four main eastern boundary upwelling systems (EBUS). In spite of their significant biological and chemical roles, through the offshore exportation of nutrient-rich waters, the physical processes that generate them are still not completely understood. This paper is a process-oriented study of filament generation mechanisms. Our goal is twofold: firstly, to obtain a numerical solution able to well represent the characteristics of the filament off Cape Ghir (30°38'N, northwestern Africa) in the Canary EBUS and secondly, to explain its formation by a simple mechanism based on the balance of potential vorticity. The first goal is achieved by the use of the ROMS model (Regional Ocean Modeling System) in embedded domains around Cape Ghir, with a horizontal resolution going up to 1.5 km for the finest domain. The latter gets its initial and boundary conditions from a parent solution and is forced by climatological, high-resolution atmospheric fields. The modeled filaments display spatial, temporal and physical characteristics in agreement with the available in situ and satellite observations. This model solution is used as a reference to compare the results with a set of process-oriented experiments. These experiments allow us to reach the second objective. Their respective solution serves to highlight the contribution of various processes in the filament generation. Since the study is focused on general processes present under climatological forcing conditions, inter-annual forcing is not necessary. The underlying idea for the filament generation is the balance of potential vorticity in the Canary EBUS: the upwelling jet is characterized by negative relative vorticity and flows southward along a narrow band of uniform potential vorticity. In the vicinity of the cape, an injection of relative vorticity induced by the wind breaks the existing vorticity balance. The upwelling jet is prevented from continuing its way southward and has to turn offshore to follow lines of equal potential vorticity. The model results highlight the essential role of wind, associated with the particular topography (coastline and bottom) around the cape. The mechanism presented here is general and thus can be applied to other EBUS.

Procesado Digital de la señal para graduados en Telecomunicaciones

Manual docente de la asignatura Procesado de la Señal del Grado en Ingeniería de las Tecnologías en Telecomunicación en la Universidad de Las Palmas de Gran Canaria. Asignatura obligatoria de tercer curso en la mención de Sistemas de Telecomunicación.

Procesado Digital de la Señal para graduados en Telecomunicación, 3ª edición

[ES] Manual docente de la asignatura Procesado de la Señal que se imparte en el segundo semestre del tercer curso (3B) del título del Grado en Ingeniería en tecnologías de la Telecomunicación. Forma parte del módulo de Tecnología Específica mención Sistemas de Telecomunicación y constituye, como asignatura única, la materia de Tratamiento de la señal. La segunda edición recoge las modificaciones fruto de la experiencia del primer año de impartición de la asignatura. Concisamente se ha agrupado todo el procesado de imagen y clasificación en un capítulo final y se han añadido al final de cada capítulo algunos problemas.

The structure of planktonic communities under variable coastal upwelling conditions off Cape Ghir (31ºN), in the Canary Current System (NW Africa)

Universidad de Las Palmas de Gran Canaria. Facultad de Ciencias del Mar. Programa de doctorado en Oceanografía. Diploma de Estudios Avanzados

Introducción a Matlab para Procesado de la Señal

[ES] Introducción a Matlab para alumnos de Procesado de la Señal

Distribution of water masses and diapycnal mixing in the Cape Verde Frontal Zone

[EN]The Cape Verde Frontal Zone separates North and South Atlantic Central Waters in the eastern North Atlantic Subtropical Gyre. CTD-O2 and shipboard ADCP data from three hydrographic sections carried out in September 2003 are used to study the structure of the front. Results show the relation between spatial variations of water masses and currents, demonstrating the importance of advection in the distribution of water masses. Diapycnal diffusivities due to double diffusion and vertical shear instabilities are also estimated. Existence of competition between the two processes through the water column is shown. Depth-averaged diffusivities suggest that salt fingering dominates diapycnal mixing, except areas of purest South Atlantic Central Water. Here, double diffusion processes are weak and, consequently, shear of the flow is the main process. Results also show that strong mixing induced by vertical shear is associated with a large intrusion found near the front.