Model Thermohaline Trends in the Mediterranean Sea during the Last Years: A Change with Respect to the Last Decades?

Temperature and salinity outputs from ECCO (years 93–09) and GLORYS (years 03–09) models have been used to compute the thermohaline and steric sea level trends in the surface (0–150 m), intermediate (150 m–600 m), and deep (600 m–bottom) layers of the Mediterranean Sea. Some changes with respect to the second half of the 20th century have been observed: the cooling of the upper waters of the entire eastern basin since 1950 seems to have vanished; the warming of WMDW historically reported for the second half of the last century could have reversed, although there is no agreement between both models at this point (trends of different sign are predicted); the salinification of WMDW reported for the previous decades is not observed in the south-westernmost area in the period 93–09, and a clear change from positive to negative in the steric sea level trend with respect to the period 93–05 is detected due to the sharp decreasing steric sea level of years 02–06

The Numerical Solution of the External Dirichlet Generalized Harmonic Problem for a Sphere by the Method of Probabilistic Solution

In the present paper, an algorithm for the numerical solution of the external Dirichlet generalized harmonic problem for a sphere by the method of probabilistic solution (MPS) is given, where “generalized” indicates that a boundary function has a finite number of first kind discontinuity curves. The algorithm consists of the following main stages: (1) the transition from an infinite domain to a finite domain by an inversion; (2) the consideration of a new Dirichlet generalized harmonic problem on the basis of Kelvin’s theorem for the obtained finite domain; (3) the numerical solution of the new problem for the finite domain by the MPS, which in turn is based on a computer simulation of the Weiner process; (4) finding the probabilistic solution of the posed generalized problem at any fixed points of the infinite domain by the solution of the new problem. For illustration, numerical examples are considered and results are presented.Partial funding for open access charge: Universidad de Málag

A Method to Extract Measurable Indicators of Coastal Cliff Erosion from Topographical Cliff and Beach Profiles: Application to North Norfolk and Suffolk, East England, UK

Recession of coastal cliffs (bluffs) is a significant problem globally, as around 80% of Earth’s coastlines are classified as sea cliffs. It has long been recognised that beaches control wave energy dissipation on the foreshore and, as a result, can provide protection from shoreline and cliff erosion. However, there have been few studies that have quantified the relationship between beach levels and cliff recession rates. One of the few quantitative studies has shown that there is a measurable relationship between the beach thickness (or beach wedge area (BWA) as a proxy for beach thickness) and the annual cliff top recession rate along the undefended coast of North Norfolk and Suffolk in eastern England, United Kingdom (UK). Additionally, previous studies also found that for profiles with low BWA, the annual cliff top recession rate frequency distribution follows a bimodal distribution. This observation suggests that as BWA increases, not only does cliff top recession rate become lower, but also more predictable, which has important implications for coastal stakeholders particularly for planning purposes at decadal and longer time scales. In this study, we have addressed some of the limitations of the previous analysis to make it more transferable to other study sites and applicable to longer time scales. In particular, we have automatised the extraction of cliff tops, toe locations, and BWA from elevation profiles. Most importantly, we have verified the basic assumption of space-for-time substitution in three different ways: (1) Extending the number or years analysed in a previous study from 11 to 24 years, (2) extending the number of locations at which cliff top recession rate and BWA are calculated, and (3) exploring the assumption of surface material remaining unchanged over time by using innovative 3D subsurface modelling. The present study contributes to our understanding of a poorly known aspect of cliff–beach interaction and outlines a quantitative approach that allows for simple analysis of widely available topographical elevation profiles, enabling the extraction of measurable indicators of coastal erosion

Integrated monitoring of mola mola behaviour in space and time

Over the last decade, ocean sunfish movements have been monitored worldwide using various satellite tracking methods. This study reports the near-real time monitoring of finescale (< 10 m) behaviour of sunfish. The study was conducted in southern Portugal in May 2014 and involved satellite tags and underwater and surface robotic vehicles to measure both the movements and the contextual environment of the fish. A total of four individuals were tracked using custom-made GPS satellite tags providing geolocation estimates of fine-scale resolution. These accurate positions further informed sunfish areas of restricted search (ARS), which were directly correlated to steep thermal frontal zones. Simultaneously, and for two different occasions, an Autonomous Underwater Vehicle (AUV) videorecorded the path of the tracked fish and detected buoyant particles in the water column. Importantly, the densities of these particles were also directly correlated to steep thermal gradients. Thus, both sunfish foraging behaviour (ARS) and possibly prey densities, were found to be influenced by analogous environmental conditions. In addition, the dynamic structure of the water transited by the tracked individuals was described by a Lagrangian modelling approach. The model informed the distribution of zooplankton in the region, both horizontally and in the water column, and the resultant simulated densities positively correlated with sunfish ARS behaviour estimator (r(s) = 0.184, p < 0.001). The model also revealed that tracked fish opportunistically displace with respect to subsurface current flow. Thus, we show how physical forcing and current structure provide a rationale for a predator's finescale behaviour observed over a two weeks in May 2014

Distribución y circulación de masas de agua en el Golfo de Cádiz. Variabilidad inducida por el forzamiento meteorológico

A partir de los datos recogidos en la campaña GOLFO 2001 (dividida en tres subcampañas: mesoescala 1, macroescala y mesoescala 2), se ha realizado un estudio de la circulación y distribución de masas de agua en el Golfo de Cádiz en la primavera de 2001, así como de la variabilidad inducida por el forzamiento meteorológico. El grueso de la información experimental para realizar el estudio lo forman los datos de CTD, con los que se ha realizado el análisis geostrófico en la región exterior del Golfo de Cádiz, y los datos de ADCP, que se han utilizado para el estudio de la circulación en la plataforma y talud continental. Las condiciones meteorológicas muestran que, en la mesoescala 1 y la mayor parte de la macroescala, el viento dominante fue de Poniente. En la mesoescala 2, tuvo lugar un episodio de Levante moderado. Esta variabilidad ha permitido estudiar la respuesta de las estructuras al forzamiento meteorológico. La circulación general superficial en el Golfo de Cádiz es anticiclónica con variaciones intercampañas. Con Ponientes, las corrientes se aproximan más a Cabo Santa María que son Levantes. Los cálculos geostróficos se refieren a 300m, al maximizarse así el flujo de entrada al Estrecho. El NACW es la masa de agua más representativa en los primeros 1000m de la columna de agua. En la isopicna ot=27 su temperatura y salinidad son prácticamente uniformes. La región inferior del NACW (ot=27,3) es arrastrada por el MW en la zona Norte hacia el océano abierto, en tanto que la parte superior (ot=26,6) forma el núcleo principal de la circulación anticiclónica superficial del Golfo. En la región exterior, reserva principal de NACW, el movimiento de esta masa de agua es muy reducido. El NACW aflora principalmente en las zonas de Cabo San Vicente y Cabo Santa María. El primero es un proceso de océano abierto y el segundo tiene una mayor influencia costera con tiempos de respuesta rápidos al cambio de vientos. Con Ponientes se intensifica y con Levantes se debilita o desaparece. Las aguas afloradas en Cabo San Vicente se desplazan de Oeste a Este siguiendo la corriente principal hasta 7,5W̆, donde parte son transportadas hacia el Sur o Sureste, constituyendo el filamento de Cabo Santa María, que alcanzan su máxima señal en torno a los 40-50 metros. El estudio de las mezclas superficiales permite concluir que un cambio en el régimen de vientos produce una gran variabilidad temporal de algunas estructuras espaciales (alforamiento de Cabo Santa María, señal superficial del Frente de Huelva, contracorriente costera superficial,..) en una capa relativamente somera (25 metros). La circulación superficial en la plataforma oriental en primavera-verano está formada por una celda ciclónica de mesoescala entre Cabo Santa María y la desembocadura del río Guadalquivir. La parte Norte de la celda es una contracorriente que transporta aguas cálidas hacia el Oeste, y llega a sobrepasar Cabo Santa María con Levantes según registros de ADCP. En la parte occidental se identifica un remolino ciclónico de gran coherencia en profundidad. El históricamente denominado Frente de Huelva sería la señal térmica superficial de un frente de densidad en la plataforma oriental, que se corresponde con la componente hacia el Este de la celda ciclónica oriental y que sigue circulando aún en condiciones de Levante

The Mediterranean Oscillation Teleconnection Index: Station-Based versus Principal Component Paradigms

Two different paradigms of the Mediterranean Oscillation (MO) teleconnection index have been compared in this work: station-based definitions obtained by the difference of some climate variable between two selected points in the eastern and western basins (i.e., Algiers and Cairo, Gibraltar and Israel, Marseille and Jerusalem, or south France and Levantine basin) and the principal component (PC) approach in which the index is obtained as the time series of the first mode of normalised sea level pressure anomalies across the extended Mediterranean region. Interannual to interdecadal precipitation (P), evaporation (E), E-P, and net heat flux have been correlated with the different MO indices to compare their relative importance in the long-term variability of heat and freshwater budgets over the Mediterranean Sea. On an annual basis, the PC paradigm is the most effective tool to assess the effect of the large-scale atmospheric forcing in the Mediterranean Sea because the station-based indices exhibit a very poor correlation with all climatic variables and only influence a reduced fraction of the basin. In winter, the station-based indices highly improve their ability to represent the atmospheric forcing and results are fairly independent of the paradigm used

The Numerical Solution of the External Dirichlet Generalized Harmonic Problem for a Sphere by the Method of Probabilistic Solution

In the present paper, an algorithm for the numerical solution of the external Dirichlet generalized harmonic problem for a sphere by the method of probabilistic solution (MPS) is given, where &ldquo;generalized&rdquo; indicates that a boundary function has a finite number of first kind discontinuity curves. The algorithm consists of the following main stages: (1) the transition from an infinite domain to a finite domain by an inversion; (2) the consideration of a new Dirichlet generalized harmonic problem on the basis of Kelvin&rsquo;s theorem for the obtained finite domain; (3) the numerical solution of the new problem for the finite domain by the MPS, which in turn is based on a computer simulation of the Weiner process; (4) finding the probabilistic solution of the posed generalized problem at any fixed points of the infinite domain by the solution of the new problem. For illustration, numerical examples are considered and results are presented

Curso de Física para Ingeniería de Telecomunicación

El estudio y conocimiento de los fundamentos de Física constituye un pilar importante en Ia formación de un ingeniero. El presente "Curso de Física para Ingeniería de Telecomunicación" ha sido concebido como texto base para el seguimiento de Ia asignatura de Física en Ia E.T.S. de Ingeniería de Telecomunicación de Ia Universidad de Málaga. Aunque este hecho pudiera conferir al libro una cierta especificidad, Ia intención de los autores ha sido redactar un texto que trascienda del ámbito de esta Escuela y que pueda servir de referencia en Ia enseñanza de esta materia en otros ámbitos docentes. El contenido se estructura en once capítulos, con cuatro bloques temáticos diferenciados: Ondas mecánicas, Termodinámica, Física Cuántica y Física del Estado Sólido. La explicación teórica, que ha tratado de adecuarse al nivel de conocimientos esperable en los alumnos de primer curso de Ingeniería, se acompaña con numerosos ejemplos resueltos e ilustraciones para facilitar una mejor comprensión de los conceptos fundamentales