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The dynamics associated with the propagation of unstable waves along a density front and their interaction with submarine canyons are simulated and analyzed with a fine-resolution three-dimensional primitive equation coastal ocean model. Simulations consider flow in an alongshore density front over two bottom topographies: an idealized straight shelf and a shelf incised by a canyon. The stationary circulation over the idealized shelf exhibits a geostrophic balance that is perturbed when the canyon topography is introduced. Enhanced cross-shore and vertical motions are produced as a result of the front-canyon interaction. A second set of simulations consider the effect of a small perturbation superimposed on the frontal circulation which develops growing meanders. In this case, the perturbation over the shelf grows rapidly by baroclinic instability into a steepened backward breaking wave characterized by significant cross-shore and vertical motions. The canyon topography accelerates or slows the development of the perturbation depending on the relative position of the unstable waves and the canyon. Finally, we use model results to determine the shelf-slope exchanges based on two methodologies. The first method computes the water transported across the shelf break while the second accounts for cross-shore displacements of water. The application of both approaches reveals that not all water transported across the shelf break is effectively exchanged between the shelf and the open ocean. However, cross-shore and vertical motions are enhanced by the unstable front and the submarine canyon leading to a large exchange between shelf and open ocean waters. Copyright 2008 by the American Geophysical Union.

An approach for calculating turbulent flows in a wave-current boundary layer over a slowly varying bed is presented. Waves are periodic in time with several harmonics. In this paper, we adopt a time invariant eddy viscosity model, in which the eddy viscosity is linearly proportional to the distance from the bed. The boundary-layer flow field is solved analytically in terms of Fourier components. The approach allows fast computations and can be easily included in a phase resolving wave propagation model. As a part of the results, bottom shear stress and the spatial variation of the boundary layer thickness are also obtained. Present results compare well with experimental data and can explain the asymmetries in the bottom shear stress under sawtooth shaped waves. © 2008 ASCE., The first two writers would like to thank the financial support from CSIC 2006-3-01068 and Govern Balear AE13706/2005. The third writer would like to acknowledge financial support from NSF and ONR through grants to Cornell University

Extreme value wave climate analysis at a particular site requires predicting long-term wave height levels from short duration records. In the present work we used the Peak Over Threshold (POT) model, assuming the frequency as a Poisson process and the intensity to be Pareto distributed, to characterise the spatial variability of the long-term extreme value wave climate along the Balearic Sea. Wave data used is part of the HIPOCAS database, a 44-years high resolution, spatial and temporal, wave hindcast covering an area between 38°N-42°N and 1°W-6°E, of the western Mediterranean Sea. The use of data from a homogeneous grid, instead of a single location wave data record, allows describing the spatial variability of the long-term extreme wave height levels over the whole Balearic basin. Results show that extreme values for a 50-year return period level around 11 m are found in the north sector of the Balearic Islands while in the southern part much lower extreme values are found, due to the shadow effect of the islands under severe north-eastern storms., The authors thank to Puertos del Estado (Ministerio de Fomento) for the use of HIPOCAS data base. The authors would also like to thank financial support from Govern Balear Project (UGIZC). AO would like to thank financial aid from CSIC (2006-3-01-068). FJM and MM are indebted to the Spanish Ministry of Education and Science for the funding provided in the “Ramon y Cajal” Program and FPI program, respectively. FJM and MM acknowledge the support of the Spanish Dirección General de Investigación under grants ENE2004-08172 and CGL2005-05365/CLI

A new set of Boussinesq-type equations describing the free surface evolution and the corresponding depth-integrated horizontal velocity is derived with the bottom boundary layer effects included. Inside the boundary layer the eddy viscosity gradient model is employed to characterize Reynolds stresses and the eddy viscosity is further approximated as a linear function of the distance measured from the seafloor. Boundary-layer velocities are coupled with the irrotational velocity in the core region through boundary conditions. The leading order boundary layer effects on wave propagation appear in the depth-integrated continuity equation to account for the velocity deficit inside the boundary layer. This formulation is different from the conventional approach in which a bottom stress term is inserted in the momentum equation. An iterative scheme is developed to solve the new model equations for the free surface elevation, depth-integrated velocity, the bottom stress, the boundary layer thickness and the magnitude of the turbulent eddy viscosity. A numerical example for the evolution of periodic waves propagating in one-dimensional channel is discussed to illustrate the numerical procedure and physics involved. The differences between the conventional approach and the present formulation are discussed in terms of the bottom frictional stress and the free surface profiles. © 2007 Elsevier B.V. All rights reserved., AO would like to thank financial support from MEC trough the postdoctoral grant at Cornell University (EX2003-0430) and Govern Balear, UGI6ZC project. GS was supported by the visiting professor program from UCLM. PLFL would like to acknowledge the support from National Science Foundation through various grants to Cornell University

A renourishment strategy for width maintenance of a Mediterranean beach was evaluated using historical aerial photographs and topographic surveys. The 5.5 km Can Picafort beach (Balearic Islands, Spain) consists of urbanised areas with associated anthropogenic pressures, and a Natural Park extending for about 1.5 km where a backshore dune and a lagoon system have been preserved. With the exception of this protected area the beach has been recurrently nourished over the past 20 years using relatively small volumes of sand (< 40 000 m3). Historical shoreline analysis provides evidence of a reduction in shoreline variability since the beach fill program was started in 1987. The last replenishment, in May 2002, provided an opportunity for assessing this nourishment strategy. Longevity estimations based on beach fill performance indicate that partial regenerations have only a limited life span (few years). Moreover, it is suggested that decreased shoreline variability could be a side-effect related to the 'extra' amount of sediment supplied to the active beach. Both aspects should be considered in beach nourishment decision-making. © 2006 Elsevier B.V. All rights reserved.

Relatively long term time series of satellite data are nowadays available. These spatio-temporal time series of satellite observations can be employed to build empirical models, called satellite based ocean forecasting (SOFT) systems, to forecast certain aspects of future ocean states. The forecast skill of SOFT systems predicting the sea surface temperature (SST) at sub-basin spatial scale (from hundreds to thousand kilometres), has been extensively explored in previous works. Thus, these works were mostly focussed on predicting large scale patterns spatially stationary. At spatial scales smaller than sub-basin (from tens to hundred kilometres), spatio-temporal variability is more complex and propagating structures are frequently present. In this case, traditional SOFT systems based on Empirical Orthogonal Function (EOF) decompositions could not be optimal prediction systems. Instead, SOFT systems based on Complex Empirical Orthogonal Functions (CEOFs) are, a priori, better candidates to resolve these cases. In this work we study and compare the performance of an EOF and CEOF based SOFT systems forecasting the SST at weekly time scales of a propagating mesoscale structure. The SOFT system was implemented in an area of the Northern Balearic Sea (Western Mediterranean Sea) where a moving frontal structure is recurrently observed. Predictions from both SOFT systems are compared with observations and with the predictions obtained from persistence models. Results indicate that the implemented SOFT systems are superior in terms of predictability to persistence. No substantial differences have been found between the EOF and CEOF-SOFT systems. © 2006 Elsevier B.V. All rights reserved.

Morphodynamic classification of beaches has achieved widespread acceptance in both geological and geomorphological literature. In this sense, the present work classifies twelve Mediterranean low energetic beaches according to the dimensionless fall parameter (Ω) parameter in the Island of Mallorca. Propagation of 44 yr of wave data as well as a detailed sediment study allows to provide probabilities for morphodynamical beach state on an annual and seasonal basis. Consequently, beaches in Mallorca fall between three major categories which are (a) truly reflective, (b) reflective skewed to intermediate and (c) intermediate beaches. The Mallorcan beach position in the morphodynamical scheme is close related to the physiographical and geological framework. Comparison of observed values with those obtained in the analysis leads that for gross beach classification there is agreement between predicted and real state. However on a seasonal classification, mainly during summer, there is no agreement between the predicted state and the real one. As the model does not incorporate the role of summer sea breezes, beach reflective states are highlighted. Real beach configurations correspond to more energetic wave dynamic conditions and to intermediate state scenarios. © 2007 Elsevier B.V. All rights reserved., Financial support from the Balearic Island Government is greatly acknowledged (UGIZ project). Support in experimental sediment characterization from J. Guillén from CMIMA (CSIC) and J.J. Fornós from UIB is greatly appreciated. Field support from B. Casas and P. Balaguer is also acknowledged. Critical comments from Dr. E. Anthony and two anonymous referees have improved substantially the first manuscript. The authors thank Puertos del Estado (Ministerio de Fomento) and Mr. Enrique Álvarez for the use of HIPOCAS database. FJM is indebted to the Spanish Ministry of Education and Science for the funding provided in the “Ramon y Cajal” Program

Jordi, Antoni et al., The oil spill from Prestige tanker showed the importance of scientifically based protocols to minimize the impacts on the environment. In this work, we describe a new forecasting system to predict oil spill trajectories and their potential impacts on the coastal zone. The system is formed of three main interconnected modules that address different capabilities: (1) an operational circulation sub-system that includes nested models at different scales, data collection with near-real time assimilation, new tools for initialization or assimilation based on genetic algorithms and feature-oriented strategic sampling; (2) an oil spill coastal sub-system that allows simulation of the trajectories and fate of spilled oil together with evaluation of coastal zone vulnerability using environmental sensitivity indexes; (3) a risk management sub-system for decision support based on GIS technology. The system is applied to the Mediterranean Sea where surface currents are highly variable in space and time, and interactions between local, sub-basin and basin scale increase the non-linear interactions effects which need to be adequately resolved at each one of the intervening scales. Besides the Mediterranean Sea is a complex reduced scale ocean representing a real scientific and technological challenge for operational oceanography and particularly for oil spill response and search and rescue operations. © 2005 Elsevier Ltd. All rights reserved.

The existence and spatial distribution of possible teleconnections between the South Pacific and North Atlantic oceans and the Ligurian Sea (North-western Mediterranean) are investigated in the present paper. Teleconnections are searched by cross-correlating monthly spatio-temporal time series of 1.1 km resolution sea surface temperature (SST), and a 22.2 km resolution sea level anomaly (SLA), measured from satellite from March 1993 to August 1999, with two indices characterising the South Pacific and the North Atlantic variability: the Southern Oscillation (SO) and the North Atlantic Oscillation (NAO) indices, respectively. Concerning the variability induced by the North Atlantic Ocean, it is shown that it mostly influences the SLA field in the Ligurian Sea. Specifically, relevant anti-correlations between SLA and North Atlantic variability have been found in all the Ligurian sub-basin. As expected by geographical proximity, the effects of North Atlantic on the SLA field in the Ligurian Sea are instantaneous at monthly time scales. Instead, correlations between SST and NAO Index are found at time lag τ = 1 month in the southern part of the basin highlighting the memory of the ocean related to their heat capacity. Significant anti-correlations between SO Index and the SST field in the Ligurian Sea, were obtained at time lag τ = 4 months in the coastal areas of the sub-basin. Results also indicate that the impact of teleconnections in the area studied is not geographically uniform. © 2005 Elsevier Ltd. All rights reserved.

This paper presents a study of coastal trapped waves on the continental margin of the northwestern Mediterranean. Cyclonically propagating waves along the coast were determined by cross-correlating alongshore current and sea level time series measured at different locations. Significant correlations between alongshore current time series were obtained at different time lags corresponding to the first three coastal trapped waves (CTW) modes. However, correlations between sea level time series were just found for the first CTW mode. The wind-forced coastal trapped theory (with bottom friction and scattering) was applied to the region and model output was compared with data. This application used five coastal sections, a summer or winter stratification, and winds from five coastal sites. The model was able to successfully reproduce observed alongshore current fluctuations in the Catalan Sea. The impact of stratification on CTW was proposed as the mechanism which reduces the effect of the complex topography on low-frequency alongshore flow. © 2004 Elsevier Ltd. All rights reserved.

This work hsa been supported by the SOFT-EVK3-CT-2000-0028 European Project and the Spanish Project REN 2001-3982-E

Satellites are the only systems able to provide continuous information on the spatiotemporal variability of vast areas of the ocean. Relatively long-term time series of satellite data are nowadays available. These spatiotemporal time series of satellite observations can be employed to build empirical models, called satellite-based ocean forecasting (SOFT) systems, to forecast certain aspects of future ocean states. SOFT systems can predict satellite-observed fields at different timescales. The forecast skill of SOFT systems forecasting the sea surface temperature (SST) at monthly timescales has been extensively explored in previous works. In this work we study the performance of two SOFT systems forecasting, respectively, the SST and sea level anomaly (SLA) at weekly timescales, that is, providing forecasts of the weekly averaged SST and SLA fields with 1 week in advance. The SOFT systems were implemented in the Ligurian Sea (Western Mediterranean Sea). Predictions from the SOFT systems are compared with observations and with the predictions obtained from persistence models. Results indicate that the SOFT system forecasting the SST field is always superior in terms of predictability to persistence. Minimum prediction errors in the SST are obtained during winter and spring seasons. On the other hand, the biggest differences between the performance of SOFT and persistence models are found during summer and autumn. These changes in the predictability are explained on the basis of the particular variability of the SST field in the Ligurian Sea. Concerning the SLA field, no improvements with respect to persistence have been found for the SOFT system forecasting the SLA field. Copyright 2004 by the American Geophysical Union., This work hsa been supported by the SOFT-EVK3-CT-2000-0028 European Project and the Spanish Project REN 2001-3982-E

The system described employs a nonlinear forecasting technique based on a combination of genetic algorithms and empirical orthogonal function (EOF) analysis. The genetic algorithm identifies the equations that best describe the behaviour of the different temporal orthogonal functions in the EOF decomposition and therefore, enables global forecasting of future time variability. The method is applied to obtain a one-month ahead forecast of the monthly mean space-time variability of the sea surface temperature (SST) of the Tuscan Archipelago, northwest coast of Italy. The system performance has been validated comparing forecast fields with real satellite observations. Results indicate that the system provides better predictions than those based on climatology. Future research is oriented to make the system applicable to military operations, environmental control and fisheries activities., The work has been supported by the North Atlantic Treaty Organization and the EVK3-CT-2000-00028 European Project

The aim of the SOFT project is to develop a new ocean forecasting system by using a combination of satellite dat, evolutionary programming and numerical ocean models. To achieve this objective two steps are proved: (1) to obtain an accurate ocean forecasting system using genetic algorithms based on satellite data; and (2) to integrate the above new system into existing deterministic numerical models. Evolutionary programming will be employed to build 'intelligent' systems that, learning form the past ocean variability and considering the present ocean state, will be able to infer near future ocean conditions. Validation of the forecast skill will be carried out by comparing the forecasts fields with satellite and in situ observations. Validation with satellite observations will provide the expected errors in the forecasting system. Validation with in situ data will indicate the capabilities of the satellite based forecast information to improve the performance of the numerical ocean models. This later validation will be accomplished considering in situ measurements in a specific oceanographic area at two different periods of time. The first set of observations will be employed to feed the hybrid systems while the second set will be used to validate the hybrid and traditional numerical model results.© (2002) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

It has been recently postulated that the irregular dynamics of El Nino-Southern Oscillation (ENSO) may embed a low order chaotic process12. If true, some aspects of the ENSO variability are predictable. Here, from observations of the annual average Sea Surface Temperature (SST) of the tropical Pacific Ocean (1949-1981) and using an evolutionary genetic analysis, we characterise the chaotic nature of ENSO. The mathematical model of the ENSO dynamics obtained is cross-validated with the observations for the next fifteen years (1982-1997). The extracted ENSO dynamics show a chaotic behaviour characterised by a correlation dimension d=3.5, in agreement with numerical simulations{2}. An eight years forecast (1997-2005) of the ENSO shows a strong cooling (La Nina) during 1999 and a significant El Nino in 2001. Finally, a longer term forecast reveals a warming of about 0.2 Celsius per century that might be associated with very low frequency variability of ENSO.

Posidonia oceanica, the dominant seagrass species in the Mediterranean, appears to be experiencing widespread loss. Efforts to conserve Posidonia oceanica are increasing, as reflected in the increase in the number of marine protected areas in the Mediterranean. However, the effectiveness of these measures to conserve seagrass meadows is unknown. In this study, the present status of the Posidonia oceanica meadows in the Cabrera National Park (Mediterranean), the only marine national park in Spain, was assessed, and the effectiveness of the conservation measures adopted was tested. This was done by reconstruction of past and present growth, quantification of the demographic status of the established meadows, and quantification of patch formation and growth rates in areas where recolonization is occurring. The meadows extended from 1-43 m deep at Santa Maria bay and from 1-33 m at Es Port. Leaf production rate of the stands examined ranged between 6.5 and 7.8 leaves shoot-1 yr-1, with higher rates in Santa Maria than in Es Port. Vertical rhizomes elongated at rates ranging from 5.39-10.12mmyr-1, annual vertical growth in Santa Maria stands being larger than that in the stands developing at Es Port. Horizontal rhizomes elongated slowly (from 2.6-6.1 cm yr-1), and branching was sparse (

DARWIN is an efficient evolutionary algorithm programmed to approximate the functional relation, in symbolic form, that describes the behaviour of a time series. The search procedure is based on Darwinian theories of natural selection and survival. An initial population of potential solutions is subjected to an evolutionary process described by selection, reproduction and mutation processes which are repeated over generations until an optimum individual is finally found. DARWIN is particularly useful when the dynamical model that creates the time series is nonlinear. The code, based on a previously proposed evolutionary algorithm [Phys. Rev. E 55 (1997) 2557-2568], is programmed in Fortran 77. Darwin is actually employed as a predictor in a satellite based ocean forecasting system. © 2001 Elsevier Science B.V.

Proceedings of 33rd International Conference on Coastal Engineering (ICCE), 1-6 July 2012, Santander, Spain.-- 12 pages, 6 figures, We study the horizontal surface mixing and the transport induced by waves, using local Lyapunov exponents and high resolution data from numerical simulations of waves and currents. By choosing the proper spatial (temporal) parameters we compute the Finite Size and Finite Time Lyapunov exponents (FSLE and FTLE) focussing on the local stirring and diffusion inferred from the Lagrangian Coherent Structures (LCS). The methodology is tested by deploying a set of eight lagrangian drifters and studying the path followed against LCS derived under current field and waves and currents

A fully nonlinear Boussinessq-type model with 7 Nwogu’s α-like coefficients is considered. The model is one-layer and low-order to simplify the numerical solvability. The coefficients of the model are here considered functions of the local water depth so as to allow an improvement of the dispersive properties for narrow banded trains in very deep waters. The proposed model is fully nonlinear in weakly dispersive conditions, so that nonlinear wave decomposition in shallower waters is well reproduced.

The author emphasizes that the United States and Latin America have already achieved a significant degree of interdependence in security relationships. The future of a hemispheric relationship, he suggests, hinges in large part on the outcome of the special assembly of the Organization of American States. Private enterprise can and should play a major role in harnessing its productive resources to national development plans, and interdependence promises a rich variety of plans and options, which promises a better future for all citizens of this hemisphere.

Violence and instability, punctuated by terrorism and subversion, characterize political life in many nations today. Throughout most of the postwar period few countries, and this includes the liberal democracies, have been spared the many faces of violence and terrorism, whether from the Left, the Right, or both. With the continuing spread of terror and counterterror, with increasing violence and instability, personal insecurity and fear become widespread. Then hard-won gains in human rights come under heavy attack. In this situation violence and terror become self-justifying because through them society will be purged of its alleged evils. Or so it is argued. Yet the moral conscience of the Americas originates in, and is built upon, respect for human rights. Our Hemisphere differs in a privileged way from other regions of the globe in that this is the guiding principle under which our nations came into being.

Different remote sensing data were combined to characterise a winter anticyclonic eddy in the southeastern Bay of Biscay and to infer its effects on cross-shelf exchanges, in a period when typical along shelf-slope currents depict a cyclonic pattern. While the joint analysis of available satellite data (infrared, visible and altimetry) permitted the characterisation and tracking of the anticyclone properties and path, data from a coastal high-frequency radar system enabled a quantitative analysis of the surface cross-shelf transports associated with this anticyclone. The warm core anticyclone had a diameter of around 50 km, maximum azimuthal velocities near 50 cm s− 1 and a relative vorticity of up to −0.45f. The eddy generation occurred after the relaxation of a cyclonic wind-driven current regime over the shelf-slope; then, the eddy remained stationary for several weeks until it started to drift northwards along the shelf break. The surface signature of this eddy was observed by means of high-frequency radar data for 20 consecutive days, providing a unique opportunity to characterise and quantify, from a Lagrangian perspective, the associated transport and its effect on the Chl-a surface distribution. We observed the presence of mesoscale structures with similar characteristics in the area during different winters within the period 2011–2014. Our results suggest that the eddy-induced recurrent cross-shelf export is an effective mechanism for the expansion of coastal productive waters into the adjacent oligotrophic ocean basin.

12 pages, 11 figures, 2 tables, 3 appendices, Video monitoring systems have become a powerful and low-cost tool in coastal studies. Extrinsic calibration of the cameras is compulsory to get quantitative information from the images. This paper presents an Open Source Software for extrinsic calibration and for the generation of related products such as planviews and time stacks. The methodology employed for extrinsic calibration minimizes errors comprising ground control points, the camera position, and, whenever is available, the horizon line. The dip of the horizon due to Earth curvature is corrected for. Planview generation is performed in such a way that the user can decide the smoothing degree in the transition zone between cameras. Time stack generation has been designed to save the minimum number of pixels in order to obtain the desired transect in the real world. The reader will find a versatile software meant to manage large data sets in a simple way, This research has been partly funded by the Spanish Government projects CTM2012-35398, CTM2015-66225-C2-1-P, and CTM2015-66225-C2-2-P (MINECO/FEDER)

In the past, it has been postulated that the irregular dynamics of the solar cycle may embed a low order chaotic process (Weiss 1988, 1994; Spiegel 1994) which, if true, implies that the future behaviour of solar activity should be predictable. Here, starting from the historical record of Zurich sunspot numbers, we build a dynamical model of the solar cycle which allows us to make a long-term forecast of its behaviour. Firstly, the deterministic part of the time series has been reconstructed using the Singular Spectrum Analysis and then an evolutionary algorithm (Alvarez et al. 2001), based on Darwinian theories of natural selection and survival and ideally suited for non-linear time series, has been applied. Then, the predictive capability of the algorithm has been tested by comparing the behaviour of solar cycles 19{22 with forecasts made with the algorithm, obtaining results which show reasonable agreement with the known behaviour of those cycles. Next, the forecast of the future behaviour of solar cycle 23 has been performed and the results point out that the level of activity during this cycle will be somewhat smaller than in the two previous ones.

New monitoring technologies are being progressively implemented in open-ocean and coastal observatories. The Mediterranean Sea is a well-known, reduced-scale ocean, an ideal natural laboratory to study global ocean processes, in particular those associated with meso- and submesoscale variability, interactions with mean flows and associated ecosystem response. SOCIB, the Balearic Islands Coastal Ocean Observing and Forecasting System, is one of such observatories, a multiplatform distributed and integrated system, a facility of facilities that extends from the nearshore to the open sea. SOCIB profits from the strategic position of the Balearic Islands at the Atlantic/Mediterranean transition area, one of the “hot spots” of biodiversity in the world’s oceans, and also of societal needs in islands where preservation of the environment is essential to assure both residents’ welfare and the competitiveness of the tourist sector. SOCIB is unique in that, from peer-reviewed excellence, its mission and objectives are science-, technology-, and society-driven. These types of new marine infrastructures, because of their critical mass and sustained funding, are presently establishing new ways of international cooperation, leading to major science breakthroughs, innovations in oceanographic instrumentation, and new ways of more efficient and science-based coastal and ocean management. We describe the major elements and structure of SOCIB and present some recent scientific, technological, and society-related results that are of relevance at a global ocean scale.

In this work, we analyze the seasonal evolution of a Mediterranean pocket beach and its response to different storm episodes. Magalluf, an intermediate medium sand beach located in the Bay of Palma (Balearic Islands) was monitored by topographic levelling during 14 months. Near the beach, a Posidonia oceanica meadow covers most of the seabed and appears to influence the cross-shore beach adjustment. The low variability observed during the sampling period was perturbed by two storm events that caused significant beach evolution and sediment transport. The first storm gave rise to waves from the SE, significant height = 2.4 m, cross-shore sediment transport and along-shore net sediment exchange that resulted in decreased dry beach extension to a minimum. The second storm was characterized by strong northeasterly winds and generated a set-up of 0.5 m and a nearshore drift reversal that redistributed sediment from the berm crest to the beach face, thereby increasing beach extension. Results from numerical simulations of wave propagation show the circulation patterns during both events and their influence on the beach morphology. In general terms, the beach exhibited a homeostatic behaviour characteristic of an equilibrium system.