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24 pages, 10 figures, 3 tables, Sea surface currents probably are the most relevant essential ocean variable affecting diverse societal challenges concerning the marine environmental (as, for example, safe and efficient navigation, marine pollution and ecological connectivity). This work introduces a climatological Atlas (monthly resolution) of currents in the Mediterranean and Canary–Iberian–Biscay basins, based on today's state of the art reanalyses of the ocean circulation. The focus is on surface and subsurface reanalyses (here understood as z∼0.5 and z∼15 m, respectively) provided by the Copernicus Marine Environment Monitoring Service (CMEMS). The climatological values are computed from the median of the empirical probability density functions and the Atlas also includes the variance matrix and a bimodality index to have quantitative information on their variability. For both domains, the subsurface climatological fields are reasonably consistent with circulation schemes proposed in the previous literature but clearly improving the time and space resolution of the emerging patterns. For the Canary–Iberian–Biscay domain, the monthly climatological surface currents capture accurately the characteristic seasonal signal and its transition between a favourable and non-favourable upwelling regime. In the Mediterranean basin, differences between the near-surface and the 15 m velocity fields suggest a non-negligible role of winds over the variability of the uppermost ocean layer, specially in the Eastern Mediterranean basin. This is, up to our knowledge, the first time that such near-surface climatological patterns are computed. It has been found that, in general, the resulting patterns agree with surface drifter trajectories. In several regions, interannual variability foster bimodal and multimodal probability distributions. The Atlas has been conceived with the purpose of providing a first quantitative assessment on the surface circulation, thus being a complementary tool of real-time ocean forecasting systems. The Atlas is distributed following the FAIR principles and is accompanied with a digital version, with enhanced visualization capabilities for both research and assessment, This is a contribution made with support of COSMO project funded by the Spanish Ministry of Economy, Industry and Competitiveness (Code: CTM2016-79474-R) and MEDOSMOSIS (Code: 6MED20_4.1_SP_005) funded by the INTERREG-MED program. S. González-Motos was under contract of COSMO project. The support of MEDOSMOSIS has been crucial to extend the work to the whole Mediterranean basin., The authors would like to thank the institutional support of the ‘Severo Ochoa Centre of Excellence’ accreditation (CEX2019-000928-S)

13 pages, 7 figures, 4 tables, 3 appendixes, supplementary data https://doi.org/10.1016/j.rser.2020.110105, This paper reviews different approaches to modelling the energy transition towards a zero carbon economy. It identifies a number of limitations in current approaches such as a lack of consideration of out-of-equilibrium situations (like an energy transition) and non-linear feedbacks. To tackle those issues, the new open source integrated assessment model pymedeas is introduced, which allows the exploration of the design and planning of appropriate strategies and policies for decarbonizing the energy sector at World and EU level. The main novelty of the new open-source model is that it addresses the energy transition by considering biophysical limits, availability of raw materials, and climate change impacts. This paper showcases the model capabilities through several simulation experiments to explore alternative pathways for the renewable transition. In the selected scenarios of this work, future shortage of fossil fuels is found to be the most influential factor of the simulations system evolution. Changes in efficiency and climate change damages are also important determinants influencing model outcomes, This work was supported by the European Union through the funding of the MEDEAS project under the Horizon 2020 research and innovation programme [grant agreement No 69128], With the funding support of the ‘Severo Ochoa Centre of Excellence’ accreditation (CEX2019-000928-S), of the Spanish Research Agency (AEI)

Special volume: Planet Ocean. Scientia Marina 80(Suppl.1) 2016.-- 9 pages, 2 figures, 4 tables, [EN] Phytoplankton blooms are events of production and accumulation of phytoplankton biomass that influence ecosystem dynamics and may also have effects on socio-economic activities. Among the biological factors that affect bloom dynamics, prey selection by zooplankton may play an important role. Here we consider the initial state of development of an algal bloom and analyse how a reduced grazing pressure can allow an algal species with a lower intrinsic growth rate than a competitor to become dominant. We use a simple model with two microalgal species and one zooplankton grazer to derive general relationships between phytoplankton growth and zooplankton grazing. These relationships are applied to two common grazing response functions in order to deduce the mathematical constraints that the parameters of these functions must obey to allow the dominance of the lower growth rate competitor. To assess the usefulness of the deduced relationships in a more general framework, the results are applied in the context of a multispecies ecosystem model (ERSEM), [ES] Las proliferaciones de fitoplancton son eventos de producción y acumulación de biomasa de fitoplancton que tienen una fuerte influencia tanto en la dinámica del ecosistema como en actividades socioeconómicas. Entre los factores biológicos que afectan la dinámica de las proliferaciones fitoplanctónicas, la selección de presas por el zooplancton puede jugar un papel importante. En este trabajo consideramos el estado inicial de desarrollo de una proliferación algal considerando que la presión de la predación puede permitir a una especie de algas con una menor tasa de crecimiento intrínseco que un competidor, ser dominante. Utilizamos un modelo sencillo con dos especies de microalgas y un herbívoro (zooplancton) para deducir relaciones generales entre el crecimiento del fitoplancton y la predación. Estas relaciones se aplican a dos funciones de respuesta de predación para deducir las limitaciones matemáticas que los parámetros de estas funciones deben obedecer. Para evaluar la utilidad de las relaciones deducidas en un marco más general, los resultados se aplican a un modelo de múltiples especies del ecosistema marino (ERSEM), We acknowledge the support from the BIOHAB (Biological Control of Harmful Algal Blooms in European Coastal waters) project funded by the European Commission Programme on Environment and Sustainable Development of Marine Ecosystems (ESD, FP-V, Key Action 3) under contract EVK3-CT-1999-00015. JS acknowledges a CSIC JAE-Doc contract co-funded by the FSE

The circulation in the Algerian Basin is characterized by the presence of fresh-core eddies that propagate along the coast or at distances between 100 and 200 km from the coast. Enhancements in the processing of the Soil Moisture and Ocean Salinity (SMOS) data have allowed to produce, for the first time, satellite sea surface salinity (SSS) maps in the Mediterranean Sea that capture the signature of Algerian eddies. SMOS data can be used to track them for long periods of time, especially during winter. SMOS SSS maps are well correlated with in situ measurements although the former has a smaller dynamical range. Despite this limitation, SMOS SSS maps capture the key dynamics of Algerian eddies allowing to retrieve velocities from SSS with the correct sign of vorticity.

Ocean currents play a key role in Earth’s climate, they are of major importance for navigation and human activities at sea, and impact almost all processes that take place in the ocean. Nevertheless, their observation and forecasting are still difficult. First, direct measurements of ocean currents are difficult to obtain synoptically at global scale. Consequently, it has been necessary to use Sea Surface Height and Sea Surface Temperature measurements and refer to dynamical frameworks to derive the velocity field. Second, the assimilation of the velocity field into numerical models of ocean circulation is difficult mainly due to lack of data. Recent experiments assimilating coastal-based radar data have shown that ocean currents will contribute to increase the forecast skill of surface currents, but require to be applied in multi-data assimilation approaches to allow better identification of the thermohaline structure of the ocean. In this paper we review the current knowledge on these fields and provide global and systematic view on the technologies to retrieve ocean velocities in the upper ocean and the available approaches to assimilate this information into ocean model.

Special issue Physical, chemical and biological observations and modelling of oil spills in the Mediterranean Sea.-- 18 pages, 15 figures, 3 tables, An exhaustive validation of some of the operational ocean forecast products available in the Gibraltar Strait and the Alboran Sea is here presented. The skill of two ocean model solutions (derived from the Eulerian ocean forecast systems, such as the regional CMEMS IBI and the high resolution PdE SAMPA) in reproducing the complex surface dynamics in the above areas is evaluated. To this aim, in-situ measurements from the MEDESS-GIB drifter buoy database (comprising the Lagrangian positions, derived velocities and SST values) are used as the observational reference and the temporal coverage for the validation is 3 months (September to December 2014). Two metrics, a Lagrangian separation distance and a skill score, have been applied to evaluate the performance of the modelling systems in reproducing the observed trajectories. Furthermore, the SST validation with in-situ data is carried out by means of validating the model solutions with L3 satellite SST products. The Copernicus regional IBI products are evaluated in an extended domain, beyond the Alboran Sea, and covering western Mediterranean waters. This analysis reveals some strengths of the presented regional solution (i.e. realistic values of the Atlantic Jet in the Strait of Gibraltar area, realistic simulation of the Algerian Current). However, some shortcomings are also identified, with the major one being related to the simulated geographical position and intensity of the Alboran Gyres, particularly the western one. This performance limitation affects the IBI-modelled surface circulation in the entire Alboran Sea. On the other hand, the SAMPA system shows a more accurate model performance and it realistically reproduces the observed surface circulation in the area. The results reflect the effectiveness of the dynamical downscaling performed through the SAMPA system with respect to the regional IBI solution (in which SAMPA is nested), providing an objective measure of the potential added values introduced by the SAMPA downscaling solution in the Alboran Sea, As the MEDESS-GIB experiment the model validation exercise presented here was performed as part of the MEDESS4MS Project activities (Project ref. 2S-MED11-01), supported by the European Regional Development Fund in the framework of the MED Programme. [...] D. Conti is currently receiving a PhD fellowship (FPI/1543/2013) granted by the Conselleria d׳Educació, Cultura i Universitats from the Government of the Balearic Islands co-financed by the European Social Fund (Grant no. FPI/1543/2013)

7 pages, 1 figure, The main circulation patterns in the western Mediterranean are revisited and updated. The schemes are based on the previous literature, adapted and reviewed. The update concerns in particular the circulation at intermediate depths, exemplified by the Levantine Intermediate Water circulation, and includes deep water cascading and recent observations from drifting floats and mooring recordings, This is a contribution of FORMED projec (CGL2012-33989) funded by the Spanish Ministry of Economy and Competitiveness (MINECO)

Special volume: Planet Ocean. Scientia Marina 80(Suppl.1) 2016.-- 18 pages, 22 figures, 1 table, [EN] Since the mid-1980s, physical oceanographers at the Institute of Marine Sciences have been involved in the use of Lagrangian drifters as a complementary technology for their oceanographic research. As Lagrangian observations became more feasible, these researchers continued developing their own drifters in what was to be the seed of current technological activities at the Physical and Technological Oceanography Department. In this paper we overview the work done during the last 30 years with special focus on Lagrangian developments from the initial activities to the latest developments. In addition to basic oceanography research applications, Lagrangian technological developments include prototypes for measuring surface and subsurface ocean properties, for tracking purposes in search and rescue operations and pollution events, and for monitoring ice motion and thickness in the Arctic. The paper emphasizes original and unpublished technical aspects related to the latest development, [ES] Desde mediados de la década de los 80, los oceanógrafos físicos en el Instituto de Ciencias del Mar se involucraron en el uso de boyas Lagrangianas como una tecnología complementaria para su investigación oceanográfica. A medida que las observaciones Lagrangianas se volvieron más factibles, los investigadores continuaron desarrollando sus propios flotadores en lo que se convirtió en la semilla de las actuales actividades tecnológicas llevadas a cabo en el Departamento de Oceanografía Física y Tecnológica. En este artículo se presenta una visión general del trabajo realizado durante los últimos 30 años, con especial énfasis en el uso de flotadores a la deriva y desarrollos propios desde su inicio hasta las aplicaciones más recientes. Además de estudios básicos de investigación oceanográfica, los desarrollos tecnológicos llevados a cabo incluyen prototipos para medir las propiedades superficiales y sub-superficiales, para tareas de seguimiento en operaciones de búsqueda y rescate y eventos de contaminación marina o para monitorizar el grosor de la capa de hielo y su movimiento en el Ártico. En este trabajo se hace hincapié en aspectos técnicos originales e inéditos relacionados con los últimos desarrollos, These include MIDAS-4 (ESP2005-06823-C05-1), MIDAS-5 (ESP2007-65667-C04-1), MIDAS-6 (AYA2010-22062-C05-01), CANOA (CTM2005-00444/MAR), MOC-2 (CTM2008-06438-C02-01), TIC-MOC (CTM2011- 28867), the Malaspina project (CSD2008-00077) and project ACI2009-0977 of the Spanish National Programme of Internationalization of R+D. E. García-Ladona, J. Salvador, P. Fernández and J.A. Jiménez wish to thank the TOSCA (G-MED09-425) and MEDESS-4MS (MED 2S-MED11-01) projects (INTERREG-IV MED programme) for funding many activities related to the ICM-PK1 drifter development; J. A. Jiménez was under contract by both projects. Financial support from the Fundación General CSIC (Programa ComFuturo) is acknowledged

García Sotillo, Marcos ... et al.-- 9 pages, 5 figures, 2 tables, On 9 September 2014, an intensive drifter deployment was carried out in the Strait of Gibraltar. In the frame of the MEDESS-4MS Project (EU MED Program), the MEDESS-GIB experiment consisted of the deployment of 35 satellite tracked drifters, mostly of CODE-type, equipped with temperature sensor sampling at a rate of 30 min. Drifters were distributed along and on both sides of the Strait of Gibraltar. The MEDESS-GIB deployment plan was designed as to ensure quasi-synoptic spatial coverage. To this end, four boats covering an area of about 680NM2 in 6 h were coordinated. As far as these authors know, this experiment is the most important exercise in the area in terms of number of drifters released. Collected satellite-tracked data along drifter trajectories have been quality controlled and processed to build the presented MEDESS-GIB database. This paper reports the MEDESS-GIB data set that comprises drifter trajectories, derived surface currents and in situ SST measurements collected along the buoys tracks. This series of data is available through the PANGAEA (Data Publisher for Earth and Environmental Science) repository, with the following doi:10.1594/PANGAEA.853701. Likewise, the MEDESS-GIB data will be incorporated as part of the Copernicus Marine historical products. The MEDESS-GIB data set provides a complete Lagrangian view of the surface inflow of Atlantic waters through the Strait of Gibraltar and thus, very useful data for further studies on the surface circulation patterns in the Alboran Sea, and their links with one of the most energetic Mediterranean Sea flows: the Algerian Current, The MEDESS-GIB experiment was performed as part of the MEDESS-4MS Project activities (Project ref. 2S-MED11-01), supported by the European Regional Development Fund in the framework of the MED Programme. D. Conti is currently a PhD fellowship (FPI/1543/2013) granted by the Conselleria d’Educació, Cultura i Universitats from the Government of the Balearic Islands co-financed by the European Social Fund. J. M. Sayol is thankful for the financial support of CSIC and FSE with the JAE-pre PhD scholarship program

In this work we report short-term measurements of the thermohaline structure and velocity field inside a narrow submarine canyon by means of a yo-yo–like profiler. An Aqualog profiler was deployed inside the Besòs Canyon in the northwestern Mediterranean continental margin, providing a unique data set on the vertical evolution of water column characteristics with unprecedented fine-scale spatial and temporal resolution. The observations reported here show a very dynamic transient short-term response with a complex vertical structure not observed previously in any submarine canyon of this region. The vertical distribution of water masses was characteristic of the western Mediterranean basin with Atlantic waters (AW) at the surface, Western Intermediate waters (WIW) in the middle and Levantine Intermediate (LIW) waters below. Turner angle and empirical orthogonal functions show that double-diffusive and isopycnal mixing are the main dominant processes at small scales. The interfaces of the three layers exhibit highly vertical excursions in relatively short times. At the surface, deepening of AW was observed, associated with flow intensification events. Deeper in the water column, within the submarine canyon confinement, the WIW-LIW interface uplifts about 100-150 m. These motions are associated with relatively up- and down-canyon–enhanced current events (up to 15-20 cm s-1 at 500 and 800 m depths) along the canyon axis. The time scales of the vertical variability were concentrated in a broad band around the semi-diurnal and local inertial frequencies within the WIW and LIW layers. En este trabajo se muestran medidas a corto plazo de la estructura termohalina y del campo de velocidad dentro de un estrecho cañón submarino a través de un perfilador tipo yo-yo. Este perfilador Aqualog se desplegó dentro del cañón del Besòs en el noroeste del margen continental del Mediterráneo, proporcionando un conjunto de datos único sobre la evolución vertical de las características de la columna de agua, con una resolución espacial y temporal a escala fina sin precedentes. Las observaciones aportadas aquí muestran una respuesta de un periodo transitorio muy dinámico con una estructura vertical compleja no observada anteriormente en ningún cañón submarino de esta región. La distribución vertical de las masas de agua es característica de la cuenca mediterránea occidental con aguas del Atlántico (AW) en la superficie, aguas occidentales Intermedias (WIW) debajo de estas y aguas de Levante Intermedio (LIW) por debajo. Los ángulos de Turner calculados y sus EOFs muestran que la estabilidad a la difusión y mezcla isopicna son los principales procesos dominantes a escalas pequeñas. Las interfaces de las tres capas exhiben excursiones notablemente verticales en tiempos relativamente cortos. En la superficie, la profundización de AW se observó asociada a eventos de intensificación del flujo. A más profundidad en la columna de agua, dentro del régimen de cañón submarino, la interfase WIW-LIW se eleva unos 100-150 m. Tales movimientos se asocian al flujo de agua hacia arriba y hacia abajo del cañón (hasta 15-20 cm s-1 a 500 y 800 m de profundidad) a lo largo del eje del cañón. Las escalas de tiempo de variabilidad vertical aparecen concentradas en una amplia banda de frecuencias alrededor de los periodos inerciales semidiurnos y locales dentro de las capas WIW y LIW.

10 pages, 13 figures, Linear and non-linear empirical models for salinity (S) are estimated from the Argo temperature (T) and salinity (delayed) data. This study focuses on the reconstruction of salinity in the upper 1200m of the eastern North Atlantic Ocean, a region characterized bythe presence of many different water masses. While previous studies have found it necessary to split this region by boxes to fit different polynomial models in each box, a unique model valid for the entire region is fitted here. Argo profiles are randomly distributed on two sets: one for fitting the models and one for testing them. Non-linear regressions are built using neural networks with a single hidden layer and the fitting data set is further divided into two subsets: one for adjusting the coefficients (training data) and one for early stopping of the fitting (validation data). Our results indicate that linear regressions perform better than the climatologic T–S relationship, but that non-linear regressions perform better than the linear ones. Non-linear training using a three-data subsets strategy successfully prevents overfitting even when networks with 90 neurons in the hidden layer are being trained. While the presence of local minima may complicate the generalization of non-linear models to new data, network committees (created by training the same network from different random initial weights) are shown to better reproduce the test data. Several predictors are tested, and the results show that geographical, or surface, information does provide significant information. These results highlight the potential applications of future satellite missions measuring sea-surface salinity to reconstruct, when combined with temperature profiles, vertical salinity profiles, This work is a contribution to the SMOS Barcelona Expert Centre on Radiometric Calibration and Ocean Salinity (SMOS-BEC), and was supported by the Spanish National Space Program, under contracts ESP2005-06823-C05 and ESP2007-65667-C04. Emilio García-Ladona wants to thank the ESEOO Spanish project (VEM2003-20577-C14-10) for their support. The data used here were collected and made freely available by the International Argo Project and the national programs that contribute to it (http://www.argo.ucsd.edu, http://argo.jcommops.org). Argo is a pilot program of the Global Ocean Observing System

14 pages, 9 figures, Nowadays Earth observation satellites provide information about many relevant variables of the ocean-climate system, such as temperature, moisture, aerosols, etc. However, to retrieve the velocity field, which is the most relevant dynamical variable, is still a technological challenge, specially in the case of oceans. New processing techniques, emerged from the theory of turbulent flows, have come to assist us in this task. In this paper, we show that multifractal techniques applied to new Sea Surface Temperature satellite products opens the way to build maps of ocean currents with unprecedented accuracy. With the application of singularity analysis, we show that global ocean circulation patterns can be retrieved in a daily basis. We compare these results with high-quality altimetry-derived geostrophic velocities, finding a quite good correspondence of the observed patterns both qualitatively and quantitatively; and this is done for the first time on a global basis, even for less active areas. The implications of this findings from the perspective both of theory and of operational applications are discussed, This is a contribution to the EU MERSEA project (AIP3-CT-2003-502885) and to the Spanish projects OCEANTECH (PIF 2006 project) and MIDAS-4 (ESP2005-06823-C05-1)

15 pages, 9 figures, 1 table.-- Issue title: "Earth Observations for Terrestrial Biodiversity and Ecosystems", In the recent years, the power of employing singularity analysis of scalar variables to perform pattern recognition in complex images has been evidenced. This approach is particularly useful when the image under study corresponds to a scalar variable submitted to a turbulent flow because, in that case, the arrangement of singularity manifolds corresponds to the multifractal hierarchy from the underlying turbulent flow. In this paper we will show how this intimate connection between Image Processing and Physics, when applied to Microwave Sea Surface Temperature images, allows to uncover global circulation patterns in the ocean at a daily basis with the resolution of 1/4 of degree. Using this technique, details not evidenced in the non-processed image are revealed. The emerging patterns provide a description of the global oceanic currents much richer than the usual global circulation scheme; in particular, instabilities, eddy generation and filamentation are distinctly identified. A pattern extraction of this kind is useful in order to measure and track mesoscale oceanic phenomena, opening the way to many operational and reanalysis applications, A. Turiel and J. Ballabrera-Poy are supported by Ramón y Cajal contracts from the Spanish Ministry of Education and Science. J. Solé is supported by a post-doc grant funded by EU Streps Project SEEDS. This is a contribution to CSIC OCEANTECH project (PIF2006), to the Spanish projects ESEOO (VEM2003-20577-C14-10) and MIDAS-4 (ESP2005-06823-C05-1), and to the European MERSEA project (EU AIP3-CT-2003-502885)

16 pages, 9 figures, A realistic 4-year dataset of the surface velocity field of the western Mediterranean Sea obtained with the Mediterranean Forecasting System and the GFDL-MOM model was used to obtain the finite-scale Lyapunov exponents (FSLE) and finite-size diffusion coefficients. Dispersive properties and Lagrangian parameters in four sub-basins are discussed, and a comparison is made between the FSLE and the Eulerian Okubo–Weiss parameter obtained for the same area with the same dataset. An additional comparison is made with the FSLE calculated from independent datasets obtained from 15 drifters launched in the Algerian basin during October of 1996, This work is a contribution to the IMAGEN project (REN-2001-0802-C02-02). Numerical simulations were done within the MFSTEP project (EVK3-CT-2002-00075)

12 pages, 9 figures, Velocity probability density functions (PDFs) are a key tool to study complex flows and are of great importance to model particle dispersion. The PDFs of geostrophic velocities derived from sea level anomalies maps for the Mediterranean Sea have been computed and analyzed, guided by recent results found in studies of two-dimensional and geostrophic turbulence. At the basin scale results show that the geostrophic velocity PDF derived from SLA maps is non-Gaussian. To understand the origin of this non-Gaussianity, a topological partition of the flow based on the Okubo–Weiss parameter is applied to separate the contribution of coherent vortices from the background field. After such separation the non-Gaussian part of the PDF appears mostly associated with the presence of such structures. Only about 20% of the vortices identified in the dataset are mainly responsible for this deviation. These vortices, called intense vortices in previous works, are those vortices with values of the amplitude larger than or equal to two standard deviations of the Okubo–Weiss parameter and correspond to vortices with a radius on the order of 40 km, This is a contribution to the IMAGEN project funded by the Spanish R D Plan (REN2001-0802-C02-02) and MERSEA project funded by the European Union (AIP3-CT-2003-502885). Altimetric maps for the period analyzed were elaborated upon and provided by CLS (Toulouse, France) under contract to the MATER project funded by the European Commission (MAS3-CT96-0051)

Special issue Workshop on Future Directions in Modelling Physical-Biological Interactions (WKFDPBI).-- 15 pages, 14 figures, A multispecies dynamic simulation model (ERSEM) was used to examine the influence of allelopathic and trophic interactions causing feeding avoidance by predators, on the formation of harmful algal blooms, under environmental scenarios typical of a Mediterranean harbour (Barcelona). The biological state variables of the model included four functional groups of phytoplankton (diatoms, toxic and non-toxic flagellates and picophytoplankton), heterotrophic flagellates, micro- and mesozooplankton and bacteria. The physical–chemical forcing (irradiance, temperature and major nutrient concentrations) was based on an actual series of measurements taken along a year cycle in the Barcelona harbour. In order to evaluate potential effects of advection, some runs were repeated after introducing a biomass loss term. Numerical simulations showed that allelopathic effects of a toxic alga on a non-toxic but otherwise similar competitor did not have appreciable influence on the dynamics of the system. However, induction of avoidance of the toxic alga by predators, which resulted on increased predation pressure on other algal groups had a significant effect on the development of algal and predator populations. The presence of advection overrided the effect of these interactions and only allowed organisms with sufficiently high potential growth rates to thrive, We acknowledge the support from the European Commissions Environment and Sustainable Development (ESD, FP-V, Research into the Development of Sustainable Marine Ecosystems, Key Action 3) under contract EVK3-CT-1999- 00015 for BIOHAB (Biological control of Harmful Algal Blooms in European coastal waters). We are specially grateful to P. Ruardij for providing the ERSEM code and for his valuable help about the use of ERSEM model

17 pages, 12 figures, 2 tables, The presence of coherent vortices makes observed mesoscale fields of the ocean resemble two-dimensional turbulence. Using this analogy, a common definition of a coherent structure has been used to study the statistical properties of Mediterranean Sea vortices observed by satellite altimeters over a 7-yr period. A vortex has been defined as the simply connected region with values of the Okubo–Weiss parameter W < −0.2σW, where σW is the spatial standard deviation of W, and the same sign of vorticity. This definition is shown to be appropriate to detect and characterize, statistically, properties such as size, mean kinetic energy, and amplitude of vortices in the Mediterranean basin from sea level anomaly maps corresponding to the period from October 1992 to October 1999. The distribution of such properties for the Mediterranean vortices suggests a heuristic criterion to extract and select very coherent and long-lived vortices from the whole set of structures identified in altimetric maps. Such coherent vortices appear to be selected for amplitudes greater than 2σW, where the amplitude has been defined in terms of the Okubo–Weiss parameter rather than vorticity, and strongly correspond to those reported from observations with independent data. Systematic locating and tracking of such vortices provide, for the first time, a general picture of their preferential paths in the Mediterranean basin, which are characterized by complex but rather well defined patterns, This is a contribution to the IMAGEN project funded by the Spanish R+D Plan (REN2001-0802-C02-02) and MERSEA project funded by the European Union 6th Framework Program (AIP3-CT-2003-502885). Jordi Isern-Fontanet has been partially supported by contracts from IMAGEN and MERSEA projects. Altimetric maps for the period analyzed were elaborated and provided by CLS (Toulouse, France) under contract of the MATER project funded by the European Union MAST Program (MAS3-CT96-0051)

Currents, particle fluxes and ecology were studied in the Palamós submarine canyon (also known as the Fonera canyon), located in the northwestern Mediterranean. Seven mooring arrays equipped with current meters and sediment traps were deployed along the main canyon axis, on the canyon walls and on the adjacent slope. Additionally, local and regional hydrographic cruises were carried out. Current data showed that mean near surface and mid-depth currents were oriented along the mean flow direction (NE-SW), although at 400 and 1200 m depth within the canyon current reversals were significant, indicating a more closed circulation inside the canyon. Mean near-bottom currents were constrained by the local bathymetry, especially at the canyon head. The most significant frequency at all levels was the inertial frequency. A second frequency of about three days, attributed to a topographic wave, was observed at all depths, suggesting that this wave was probably not trapped near the bottom. The current field observed during the most complete survey revealed a meandering pattern with cyclonic vorticity just upstream from and within the canyon. The associated vertical velocity ranged between 10 and 20 m/day and was constrained to the upper 300 m. This latter feature, together with other computations, suggests that during this survey the meander was not induced by the canyon but by some kind of instability of the mean flow. In the canyon, suspended sediment concentration, downward particle fluxes, chlorophyll and particulate C and N were significantly higher up-canyon from about 1200 m depth than offshore, defining, along with the different hydrodynamics, two canyon domains: one from the canyon head to about 1200 m depth more affected by the canyon confinement and the other deeper than 1200 m depth more controlled by the mean flow and the shelf-slope front. The higher near-bottom downward total mass fluxes were recorded in the canyon axis at 1200 m depth along with sharp turbidity increases and are related to sediment gravity flows. During the deployment period, the increase in downward particle fluxes occurred by mid-November, when a severe storm took place. On the canyon walls at 1200 m depth, suspended sediment concentrations, downward particle fluxes, chlorophyll and particulate C and N were higher on the southern wall than on the northern wall inversely to the current's energy. This could be caused by an upward water supply on the southern canyon wall and/or the mean flow interacting with the canyon bathymetry. In the swimmers collected by the sediment traps, the dominant species was an elasipod holothurian, which has not been recorded in other canyons or elsewhere in the Mediterranean, indicating particular speciation. © 2005 Elsevier Ltd. All rights reserved.

Allelopathy among microalgae has been modelled in order to fit the dynamics of mixed cultures of Chrysocromulina polylepis and Heterocapsa triquetra, carried out with three different initial concentrations of the allelopathic species C. polylepis. The experimental data have been analysed with a simple Lotka-Volterra type model including an allelopathic term. Based on the population dynamics of the two species in unialgal and mixed cultures, the model has been simplified and solved analytically. The best fit of the allelopathy parameter (γ≈10-5 to 10-6) provides a good agreement between the theoretical curve and the experimental data for the two highest initial concentrations of C. polylepis but, interestingly, shows a less accurate fit for low initial concentrations of the toxic alga. Following the same procedures, a modified model, in which the allelopathic effect is dependent on the square of the concentration of the toxic alga, has been adjusted to the experimental data. This modified model presents a good fit for all the range of initial concentrations of the toxic alga. These results allow a quantification of the strength of the allelopathic interaction between two marine phytoplankton species. The growth curve of the non-toxic alga is significantly affected by the allelopathy term only after the toxic alga has reached relatively high concentrations. This supports field observations suggesting that, at least in the case of C. polylepis, allelopathy may be important once a bloom is well developed, but is not likely to be a key factor in initial phases of the proliferation. © 2004 Published by Elsevier B.V., We acknowledge the support from the European Commissions Environment and Sustainable Development (ESD) (FP-V, research into the development of Sustainable Marine Ecosystems forms, Key action 3 under contract EVK3-CT-1999-00015) BIOHAB (Biological control of Harmful Algal Blooms in European coastal waters)

A procedure is presented to detect eddy cores from sea level anomaly (SLA) maps obtained from altimetric measurements. The method is based on finding the sign of Q, which is an invariant of the velocity gradient tensor (=u). This parameter, commonly used in studies of two-dimensional turbulence, measures the relative contribution of deformation and vorticity. Vortex cores are associated with regions with large and positive values of Q. It is shown that this parameter is adequate to detect marine eddies in altimetric maps and, when the geometry of streamline contours in SLA maps is unclear, the Q . 0 criterion appears to work more consistently. The performance of the methodology is applied, as an example, to altimetric maps of the Algerian Basin in the Western Mediterranean Sea, where two long-lived eddies are tracked. The observed trajectories are in good agreement with Advanced Very High Resolution Radiometer (AVHRR) images.

During the autumn–winter of 1996–1997, drifting buoy trajectories and infrared satellite images provided new information on the characteristics of several mesoscale phenomena generated by the Algerian Current (AC) in the western Mediterranean Sea. A mesoscale event, as defined by previous studies, consists of a meander of the current associated with a surface anticyclonic eddy inside its crest, a transitory surface cyclonic eddy (E c ) upstream from the crest, and a deep anticyclonic eddy just below the meander. Most events propagate eastward along the coast at a few km per day until they are forced, mainly by the topography at the entrance to the channel of Sardinia, to detach from the coast and propagate seaward. They thus become open-sea anticyclonic eddies and generally complete an anticlockwise circuit in the Algerian basin. Surface buoys were launched upstream from an event and across it near 1°E. They made it possible to characterise the anticyclonic and cyclonic surface eddy features, and for the first time clearly showed the meander, which is in general not well depicted with images. It has thus been definitely demonstrated that most of the AC (speeds of several tens of cm/s) crosses the relatively slowly propagating events. As usual, the event we sampled reached a mature stage characterised by a vanishing of the E c , and increased up to ∼100 km. Its arrest and decrease before it reached the channel of Sardinia, which is not so usual, was contemporaneous to the reappearance of the E c and could be related to the growing of another coastal eddy upstream. At the entrance to the channel of Sardinia (near 7–8°E), the trajectories and images also documented another event which was larger (up to ∼120 km) and in the phase of detachment. Since the buoys drifted alternately to the west and to the east between this event and the coast, it is clear that an event can detach only temporarily and allow part of the AC to flow eastward directly. As indicated by infrared images, the definitive detachment occurred after all the buoys escaped from the event. The whole in situ and satellite data set is fully consistent with all the previous observations of the AC mesoscale variability, and quantitatively supports the proposed hypotheses for the event structure. It is consistent with laboratory experiments and some results of numerical models of coastal instability processes.

The Algerian Current (AC) is one of the most energetic flows in the Mediterranean basin. A characteristic picture of this current is formed by a series of mesoscale eddies at different scales. Here, statistical analysis of 15 surface Argos buoy tracks in 1996–1997 provides a complete Lagrangian view of the AC. The buoys, released upstream and across a coastal meander between 0°E and 1°E longitude, were followed for 3 months. They travelled eastward at an average speed of 14 cm/s and showed high energetic fluctuations related to several mesoscale eddies. The characteristic integral time and space scales are highly anisotropic. For the zonal component, these are about 4 days and 66 km, and for the meridional component, about 2 days and 26 km. Representative values of effective diffusivities from single dispersion statistics are within 0.7–1.3×10 8 and 1.5–6.0×10 7 cm 2 /s for the zonal and meridional directions, respectively. A local analysis shows that mesoscale motions are particularly relevant in the region 1–3°E and 7–8°E, provided the considerably high values of eddy kinetic energy in comparison with the mean kinetic energy. Eddy–mean current interactions are evidenced by the significant changes of sign of horizontal covariance from west to east. Finally, an Eulerian picture of the AC is built, exhibiting similar trends than previous and recent field observations.

Nonlinear phenomena are essential ingredients in many oceanic and atmospheric processes, and successful understanding of them benefits from multidisciplinary collaboration between oceanographers, meteorologists, physicists and mathematicians. The present Special Issue on "Nonlinear Processes in Oceanic and Atmospheric Flows" contains selected contributions from attendants to the workshop which, in the above spirit, was held in Castro Urdiales, Spain, in July 2008. Here we summarize the Special Issue contributions, which include papers on the characterization of ocean transport in the Lagrangian and in the Eulerian frameworks, generation and variability of jets and waves, interactions of fluid flow with plankton dynamics or heavy drops, scaling in meteorological fields, and statistical properties of El Niño Southern Oscillation.

Deep slope currents and particulate matter concentrations were studied on the Barcelona continental margin in and around the Foix submarine canyon from May 1993 to April 1994. This year-long moored experiment revealed that near-bottom slope currents are strongly influenced by the bottom topography, being oriented along isobaths and along the canyon axis. The deep slope current fluctuations are controlled by the local inertial motion (18.3 h) and also by low-frequency oscillations at periods of 6–10 days, related to the passage of atmospheric pressure cells. Particulate matter concentrations recorded during the experiment do not show a clear seasonal variability, except outside the canyon, where significant peaks of particulate matter concentrations were recorded only during the winter-fall deployment. In addition, the temporal evolution of suspended particulate matter concentration is not linked to changes in the cross-slope or along-slope current components and did not show a clear relationship with river avenues or wave storm events. This suggests that suspended particulate matter exported from the shelf is dispersed on the slope by advective processes, which attenuate the signal of the shelf-slope sediment transfer. Mean particulate matter concentrations differed among sampling sites, but the magnitude of the mean horizontal suspended particle flux reflects a quite similar value in the whole study area, ranging from 2.53 to 4.05 mg m −2 s −1 . These horizontal suspended particle fluxes are 27 (canyon head) to 360 (open slope) times higher than the settling particle fluxes measured at the same sampling sites, indicating that the suspended particulate transport on the Barcelona continental slope dominates over the settling particle fluxes, even inside the Foix submarine canyon.

Special section Modeling Transport (Energy) Demand and Policies.-- 14 pages, 2 figures, 2 tables, 6 appendix, A global alternative mix to fossil fuels is proposed, based on proven renewable energy technologies that do not use scarce materials. The mix consists of a combination of onshore and offshore wind turbines, concentrating solar power stations, hydroelectricity and wave power devices attached to the offshore turbines. Solar photovoltaic power could contribute to the mix if its dependence on scarce materials is solved. The most adequate deployment areas for the power stations are studied, as well as the required space. Material requirements are studied for the generation, power transport and for some future transport systems. The order of magnitude of copper, aluminium, neodymium, lithium, nickel, zinc and platinum that may be required for the proposed solution is obtained and compared with available reserves. Overall, the proposed global alternative to fossil fuels seems technically feasible. However, lithium, nickel and platinum could become limiting materials for future vehicles fleet if no global recycling systems were implemented and rechargeable zinc-air batteries would not be developed; 60% of the current copper reserves would have to be employed in the implementation of the proposed solution. Altogether, they may become a long-term physical constraint, preventing the continuation of the usual exponential growth of energy consumption. © 2011 Elsevier Ltd

8 pages, 1 figure, 4 tables, Automated Taxon Identification (ATI) systems that use a database to identify species or anatomical structures of species from different taxonomical groups have recently been developed. However, few of these works have been applied to marine organisms. In this paper we develop an ATI system for identifying Actynopterigian species from their otolith contour; this is important information for the palaeontological, ictiological and ecological sciences, especially in food web studies. The AFORO website comprises the first web-based automated species identification system based exclusively on otolith shape outline. Species are identified iteratively based on a multiscale representation of the otolith contour. The ATI system is very easy to use as it only requires uploading a suitably oriented otolith image on a black background. Two tests were carried out with a database of 1480 images of left sacullar otoliths (sagittae) from 420 species. The first test analysed 50 different otoliths, 10 per species, from 5 different species. The second test identified 50 otoliths, each from a different species. The two tests obtained similar results (percentage of correct identifications): 72% of specimens were correctly identified at species level, and the percentage increased to 90% at genus level and reached 94% at family level. The best results are obtained for species which have an otolith contour with a very specific morphology, such as the mackerel Scomber colias, and the less efficient results for species with common shaped otoliths with unclear specific characteristics, such as the Mediterranean horse-mackerel Trachurus mediterraneus, or species with large morphological variability between individuals, such as Lophius budegassa or Synodus saurus, This work has been supported by the MICYT TIC2000-0376-p4-04, MEC PTR1995-0810-OP and MEC CGL2007-29846-E/BOS projects

Transport and mixing properties of surface currents can be detected from altimetric data by both Eulerian and Lagrangian diagnostics. In contrast with Eulerian diagnostics, Lagrangian tools like the local Lyapunov exponents have the advantage of exploiting both spatial and temporal variability of the velocity field and are in principle able to unveil subgrid filaments generated by chaotic stirring. However, one may wonder whether this theoretical advantage is of practical interest in real-data, mesoscale and sub-mesoscale analysis, because of the uncertainties and resolution of altimetric products, and the non-passive nature of biogeochemical tracers. Here we compare the ability of standard Eulerian diagnostics and the finite-size Lyapunov exponent in detecting instantaneous and climatological transport and mixing properties in the south-western Mediterranean. By comparing with sea-surface temperature patterns, we find that the two approaches provide similar results for slowly evolving eddies like the first Alboran gyre. However, the Lyapunov exponent is also able to predict the (sub-)mesoscale filamentary processes occurring along the Algerian current and above the Balearic Abyssal Plain. Such filaments are also observed, with some mismatch, in sea-surface temperature patterns. Climatologies of Lyapunov exponents do not show any compact relation with other Eulerian diagnostics, unveiling a different structure even at the basin scale. We conclude that filamentation dynamics can be detected by reprocessing available altimetric data with Lagrangian tools, giving insight into (sub-)mesoscale stirring processes relevant to tracer observations and complementing traditional Eulerian diagnostics. (C) 2008 Elsevier Ltd. All rights reserved.

A methodology for recovering salinity from expendable bathythermograph (XBT) data is presented. The procedure exploits climatological relationships between temperature, salinity and depth to build regional characteristic curves by fitting a polynomial function that minimises both the variance of residuals and unknowns. Hence, salinity is computed and recovered as a function of temperature and depth. Empirical formula are provided to recover the salinity field from temperature-depth measurements for the Cantabrian Sea and Galician Area. The method is validated and applied in the context of two marine rescue exercises carried out in the Bay of Biscay close to the north coast of Spain and in the Finisterre region, where a series of XBT and conductivity-temperature-depth (CTD) profiles were acquired during fast samplings. The results agree reasonably well with independent data in terms of the spatial structure, with the largest errors in the upper 100 m of the ocean and at intermediate levels. The first diagnoses of the surface geostrophic velocity fields obtained through the salinity reconstruction are coherent and may help in rescue and safety operations during marine emergencies. Hence, we recommend that a technical unit should consider this kind of expandable sampling strategy with both XBT and XCTD data during marine emergencies, since it provides useful and comprehensive information rapidly with minimal interference by means of formal operations on board search and rescue ships., Presentamos una metodología para el cálculo de la salinidad a partir de datos de XBT. El procedimiento hace uso de la relación climatológica S-T-d para construir curvas características de la región ajustando una función polinomial que minimiza tanto la varianza del residuo como de las incógnitas. De esta manera, la salinidad es calculada en función de la temperatura y la profundidad. Estas expresiones empíricas se han empleado para estimar el campo de salinidad a partir de medidas de temperatura y profundidad realizadas en el Mar Cantábrico y en el área de Galicia. El método se ha validado y aplicado en el contexto de dos ejercicios de salvamento marítimo, llevados a cabo en el Golfo de Vizcaya y en la región de Finisterre, donde se lanzaron XBT’s en muestreos rápidos y se obtuvieron perfiles de CTD. Los resultados muestran una coherencia razonable al compararlos con datos independientes en términos de la estructura espacial, con errores más importantes en los 100 m superiores de la columna de agua y en capas intermedias. Los primeros diagnósticos de la velocidad geostrófia en superficie son igualmente coherentes y pueden ser de gran ayuda en operaciones de salvamento y rescate durante emergencias en el mar. Por tanto, recomendamos a la Unidad Técnica que en situaciones de emergencia considere la posibilidad de realizar campañas con sondas desechables (XBT’s y XCTD’s), en tanto que este proceso es rápido, no interfiere con otras operaciones de salvamento y ofrece información de gran utilidad.

Within the tasks devoted to operational oceanography, a tool has been developed to access, visualize and distribute satellite data from an HPRT receiving station located in the Institut de Ciencies del Mar (CMIMA-CSIC). The tool generically called SAIDIN (SAtellite Image Database INterface) has been developed with the purpose to access and provide data to a wide spectrum of users. New improvements have been made in order to provide facilities that could be of great potential interest within monitoring tasks in accidental marine pollution discharges. SAIDIN has been integrated as a viewer of THREDDS (Thematic Realtime Environmental Distributed Data Services) catalog of UNIDATA.

12 pages, 13 figures, 1 table, The surface salinity response to changes of various external forcings and model parameters is investigated in a regional 1/3° configuration of the NEMO-OPA model implemented over the eastern North-Atlantic subtropical Ocean. Fourteen realistic climatological simulations are run. By default, neither relaxation to climatological surface salinity nor temperature is included. Forcing fields and parameters expected to impact the surface salinity are modified. These include: the wind stress, the surface temperature, wind speed and relative humidity entering the bulk calculation for sensible and latent heat fluxes, the precipitation, the data specified at open boundaries, the lateral viscosity operator, the salt lateral diffusivity, the vertical mixing scheme, the on/off switch of the double diffusion parameterization, the river runoffs and the SSS/SST restoring terms. The SSS standard deviation over this ensemble of model simulations is of the order of 0.1 psu, which is also the order of the annual cycle of the surface salinity field in this area., In this experimental framework, the wind stress is found to have the largest impact on the model SSS, both in terms of mean field and annual variability. The sensitivity to the precipitation, atmospheric temperature, open boundary external data, and to the relaxation to climatological SSS and SST, is also significant. Of all the model parameterizations, the lateral salt diffusivity is the one associated to the strongest surface salinity model response. This work allows the identification of the main sources of error for model surface salinity. It paves the way for a more comprehensive investigation of SSS model error statistics, which is needed for future data assimilation experiments motivated by the close launch of the new SSS-observing SMOS and Aquarius satellite missions, This work was supported by the Spanish National Program on Space, under contracts ESP2004-00671 and ESP2005-06823-C05

18 pages, 15 figures, 2 tables The ESEOO Project, launched after the Prestige crisis, has boosted operational oceanography capacities in Spain, creating new operational oceanographic services and increasing synergies between these new operational tools and already existing systems. In consequence, the present preparedness to face an oil-spill crisis is enhanced, significantly improving the operational response regarding ocean, meteorological and oil-spill monitoring and forecasting. A key aspect of this progress has been the agreement between the scientific community and the Spanish Search and Rescue Institution (SASEMAR), significantly favoured within the ESEOO framework. Important achievements of this collaboration are: (1) the design of protocols that at the crisis time provide operational state-of-the-art information, derived from both forecasting and observing systems; (2) the establishment, in case of oil-spill crisis, of a new specialized unit, named USyP, to monitor and forecast the marine oceanographic situation, providing the required met-ocean and oil-spill information for the crisis managers. The oil-spill crisis scenario simulated during the international search and rescue Exercise “Gijón-2006”, organized by SASEMAR, represented an excellent opportunity to test the capabilities and the effectiveness of this USyP unit, as well as the protocols established to analyze and transfer information. The results presented in this work illustrate the effectiveness of the operational approach, and constitute an encouraging and improved base to face oil-spill crisis This work has been supported by the ESEOO Project (VEM2003-20577-C14-08), funded by the Spanish Ministry of Science and Technology. S. Castanedo would like to thank the Spanish Ministry of Science and Technology for the support under Ramon y Cajal Program. Crews from the ships that participated in the Exercise Gijón-2006 are also gratefully acknowledged

2 pages, 2 figures.-- PAMM Special issue: "Sixth International Congress on Industrial Applied Mathematics (ICIAM07) and GAMM Annual Meeting, Zürich 2007", We summarize recent work on the location of Lagrangian structures in velocity fields obtained from realistic simulations and from satellite altimetry of the surface layers of the Mediterranean sea. Finite-size Lyapunov exponents are found to be useful quantities to characterize stretching and compressing structures, and their implications for mixing. Direct calculation of hyperbolic points and their stable and unstable manifolds identifies ocean structures, and allows the use of the tools of lobe dynamics to characterize fluid transport, Parts of this work have been supported by CSIC (grants PI-200650I224 and OCEANTECH), Royal Society-CSIC cooperation agreement (B2003GB03), MEC and FEDER (projects IMAGEN, CONOCE2 and FISICOS), ONR (Grant No. N00014-01-1-0769), and European Commission (projects MERSEA and 024717-DEMETRA)

[1] Oceans and 2D turbulence present similar characteristics, as for instance the dominant role played by eddies in energy and matter transport. However, providing a complete justification of this analogy is difficult, as it requires knowledge of the ocean's dynamic state at different instants and over large scales. Recently, new techniques coming from the Microcanonical Multifractal Formalism have made it possible to infer the streamlines from the analysis of satellite images of some scalar variables. In this paper, we will show that this information is enough to characterize the scaling properties of the energy cascade, which is manifested as a multifractal signature; further, the multifractal signature is obtained at each location in a local basis. Different scalars obtained from satellite measurements such as Sea Surface Temperature or Surface Chlorophyll Concentration present essentially the same multifractal structure, which is interpreted as a consequence of the pervading character of the turbulent advection at the scales of observation.

17 pages, 7 figures, 2 tables, Because of the optimal features of wavelet processing, the use of wavelets for describing and analyzing signals in 2D turbulence has been generalized since a decade ago. In spite of the close analogy between 2D turbulence and geophysical fluid dynamics, few works have tried to generalize the rich framework of wavelet techniques to the study of experimental signals in oceanography. In this paper, the authors extend a prominent wavelet technique designed for the study of direct numerical simulations (DNSs) on 2D turbulence, the coherent vortex simulation, and analyze with it ocean velocity fields obtained from sea surface height maps derived from satellite altimetry. The authors demonstrate the pertinence of this technique to describe altimetry data, resulting in a description of oceanic flows with a reduced number of degrees of freedom. In particular, it is shown that the western Mediterranean circulation is well approximated by a field of extracted coherent vortices when an appropriate wavelet basis is employed as a filter; however, about one-third of the energy is lost in this description, evidencing important differences between results obtained on the frame of 2D turbulence and oceanic data, This is a contribution to the IMAGEN (Spanish R+D Plan: Grant REN2001-0802-C02-02) and MERSEA projects (Grant EU AIP3-CT- 2003-502885). A. Turiel is funded by a Ramón y Cajal fellowship from the Spanish Ministry of Education. The altimeter products were produced by Ssalto/Duacs and distributed by AVISO with support from CNES

10 pages, 4 figures We demonstrate the potential of monitoring coherent wave fronts on the tropical ocean surface using an advanced detection algorithm applied to visible sunglint-affected imagery from geostationary satellites. Data from MeteoSat are processed with the advanced analysis technique to reveal transient wave activity near and to the west of the Mascarene Ridge of the western Indian Ocean. The technique is based on a wavelet-based singularity analysis which enhances the subtle but highly coherent wave patterns in the meteorological satellite data. It is likely that the patterns represent internal ocean waves, a pathway to ocean mixing and climate. The prospect for using this detection algorithm in greatly expanded satellite global surveys of wave activity is outlined This is a contribution to the IMAGEN (Spanish R+D Plan: REN2001-0802-C02-02) and MERSEA projects (EU AIP3-CT-2003-502885). A. Turiel is funded by a Ramón y Cajal contract from the Spanish Ministry of Education. J. Isern-Fontanet is funded by a post-doctoral grant by the Spanish Ministry of Education. J. Young’s visit to ICM was provided by a sabbatical and Graduate School WARF funding from the University of Wisconsin-Madison. We thank EUMETSAT for leaving us their data

18 pages, 11 figures, supporting information http://onlinelibrary.wiley.com/doi/10.1029/2006JC003878/suppinfo, In this paper we investigate the validity of the multifractal formalism to study sea surface temperature (SST). It is shown that SST patterns observed in moderate resolution SST images have anomalous scaling properties characteristic of a multifractal structure. The most probable origin of the observed structures is the turbulent character of the oceanic flow as they evolve slowly and are very persistent in times compatible with ocean mesoscale dynamics (several days). The spectrum of singularity exponents indicates that the dynamics of the processes leading to the geometrical arrangement of the SST patterns is quite general over the available range of scales. As a consequence, multifractal techniques can be used to extract properties of the underlying flow. In particular, the geometry of the SST multifractal components is closely linked with the ocean flow, which allows to build a reasonable guess of the streamfunction (defined as the maximum singular streamfunction (MSS)) from a single SST image. Thus the ocean surface velocity field can be easily inferred, with some limitations. As multifractal analysis is in essence a geometrical approach, the method is able to retrieve a high resolution velocity field, well localized in space, but with some indetermination on the modulus and sense of velocity vectors. To solve this, a general framework for the integration of extra information is proposed, what is illustrated with an example merging MSS with altimetric data, This is a contribution to the EU MERSEA project (AIP3-CT-2003-502885) and to the Spanish projects ESEOO (VEM2003-20577-C14-10) and MIDAS-4 (ESP2005-06823-C05-1). A. Turiel is funded by a Ramón y Cajal fellowship from the Spanish Ministry of Education. The AVHRR Oceans Pathfinder SST data were obtained from the Physical Oceanography Distributed Active Archive Center (PO.DAAC) at the NASA Jet Propulsion Laboratory, Pasadena, California. The altimeter products were produced by the CLS Space Oceanography Division as part of the Environment and Climate EU ENACT project (EVK2-CT2001-00117) and with support from CNES

4 pages, 5 figures.-- © 2007 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works, Recent advances in the theory of turbulence, with the introduction of the Microcanonical Multifractal Formalism has favored the development of new techniques for the analysis of remotely sensed data, particularly of scalers as SST. In this work we show that these techniques allow to uncover a fascinating picture in which many features of global ocean circulation patterns emerge in a distinct way. Applications include the characterization of transport, estimation of eddy-mediated mixing, the characterization of the coupling of ENSO perturbation with the equatorial instabilities and a long etc, A. Turiel is contracted under the Ramón y Cajal program by the Spanish Ministry of Education. J. Solé is supported by a post-doc grant funded by EU Streps Project SEEDS. V. Nieves is funded by the EU IP Project MERSEA. This is a contribution to CSIC OCEANTECH project (PIF2006), to the Spanish project MIDAS-4 (ESP2005-06823-C05-1), and to the European MERSEA project (EU AIP3-CT-2003-502885)

9 pages, 5 figures, A feature of marine plankton communities is the occurrence of rapid population explosions. When the blooming species are directly or indirectly noxious for humans, these proliferations are denoted as harmful algal blooms (HAB). The importance of biological interactions for the appearance of HABs, in particular when the proliferating microalgae produce toxins that affect other organisms in the food web, remains still poorly understood. Here we analyse the role of toxins produced by a microalgal species and affecting its predators, in determining the success of that species as a bloom former. A three-species predator–prey model is used to define a criterion that determines whether a toxic microalga will be able to initiate a bloom in competition against a non-toxic one with higher growth rate. Dominance of the toxic species depends on a critical parameter that defines the degree of feeding selectivity by grazers. The criterion is applied to a particular simplified model and to numerical simulations of a full marine ecosystem model. The results suggest that the release of toxic compounds affecting predators may be a plausible biological factor in allowing the development of HABs, We acknowledge the support from BIOHAB (Biological control of Harmful Algal Blooms in European coastal waters) project funded by the European Commission Program on Environment and Sustainable Development of Marine Ecosystems (ESD, FP-V, Key Action 3) under contract EVK3-CT-1999- 00015. We are grateful to two anonymous referees for very helpful criticism and constructive comments

6 pages, 3 figures., [EN] We present an automatic system for describing and identifying fish otolith shapes combining information technologies with modern advances in signal analysis. As a major novelty with respect to past studies the system includes wavelets (WT) and curvature space scale (CSS) analyses that have been shown to provide local morphologic information and characteristics (landmarks) of the sagitta otolith outline for non-specialists. By applying this electronic catalogue directly the system is very helpful for determining teleostean fish size, population and species. Both the electronic catalogue and the shape analysis are implemented through the AFORO database, which at present contains more than 1250 high resolution images of the left sagitta from 292 species and 94 families of teleostan fishes sampled mainly in Mediterranean and Antarctic waters, [ES] Se ha elaborado un sistema automático que describe e identifica las formas de otolitos de peces a partir de la combinación de tecnologías de la información y modernos avances en análisis de señal. Respecto a otros sistemas, éste presenta como principal novedad el uso de análisis de formas basados en la aplicación de wavelets (WT) y análisis de la curvatura a diferentes escalas (CSS). Estos análisis proporcionan información local de las características morfológicas del contorno externo del otolito de forma automática, facilitando la labor de identificación a no especialistas en morfología de otolitos. Una aplicación directa de este sistema facilitará la determinación del tamaño, la población y la especie en peces Teleósteos. Ambos, el sistema de análisis de formas y el catálogo de otolitos se implementan en la base de datos AFORO, que incluye actualmente, más de 1250 imágenes de alta resolución de otolitos pertenecientes a 292 especies y 94 familias de peces Teleósteos, procedentes básicamente del mar Mediterráneo y del océano Antártico, This work has been supported by the Spanish MICYT TIC2000-0376-p4-04 project

10 pages, 7 figures, 4 tables, The present study reviewed some of the critical pre-processing steps required for otolith shape characterisation for automatic classification with heterogeneous distributed data. A common procedure for optimising automatic classification is to apply data pre-processing in order to reduce the dimension of vector inputs. One of the key aspects of these pre-processing methods is the type of codification method used for describing the otolith contour. Two types of codification methods (Cartesian and Polar) were evaluated, and the limitations (loss of information) and the benefits (invariance to affine transformations) associated with each method were pointed out. The comparative study was developed using four types of shape descriptors (morphological, statistical, spectral and multiscale), and focused on data codification techniques and their effects on extracting shape features for automatic classification. A new method derived from the Karhunen–Loève transformation was proposed as the main procedure for standardising the codification of the otolith contours., The present study was funded by the IBACS project (European Union Project QLRT-2001-01610), by the Spanish project AVG-ION (McyT-TIC2000-0376-p4-04) from the Spanish Ministry of Science and Technology and by the IBACS European project.

Special issue Small and mesoscale processes and their impact on the large scale.-- 20 pages, 9 figures, Three Algerian eddies (open sea big anticyclonic eddies in the Algerian basin, western Mediterranean sea) are studied in detail using altimetric and in situ data. To characterize their spatial structure we make use of the Okubo¿Weiss parameter, which allows to separate the flow into vorticity-dominated and deformation-dominated regions. The application of this parameter to geostrophic velocity fields obtained from Sea Level Anomaly maps show that the observed eddies have a spatial structure in close resemblance to that found in coherent vortices of two-dimensional turbulence. These eddies appear to have a rather coherent vorticity-dominated core region surrounded by an outer region dominated by deformation with a very complicated and variable in time structure. This analysis is also applied to CTD data collected across three eddies sampled between 1997 and 1998. From these data eddy cores are equivalently defined as the interior region enclosed by the maximum of azimuthal velocity, and are consistent with the horizontal structures seen in SLA maps. The distinction between the core and the outer region (circulation cell) is particularly important to understand the role of transport and stirring of properties associated to eddies, as illustrated by the observed salinity structure, some selected SST images, and drifter trajectories. The core is characterized by very small isopycnal salinity gradients, while the surrounding cell is characterized by a strong slope of isohalines with respect to isopycnals. Persistent stagnation points are observed around the eddy and correspond to regions of high values of deformation with respect to vorticity. These regions allow analyzing characteristic patterns seen in the corresponding SST images. In addition, drifters trajectories exhibit very different behavior when crossing such regions, This is a contribution to ELISA and ALGERS experiments and to the IMAGEN project funded by the Spanish R+D Plan (REN2001-0802-C02-02). Jordi Isern-Fontanet has been partially supported by contracts from GRAC (2FD97-0588) and IMAGEN projects. Altimetric maps for the period analyzed were elaborated and provided by CLS (Toulouse, France) under contract of the MATER project funded by the European Commission (MAS3-CT96-0051). ELISA1, ELISA4 and ALGERS98 were also partially funded by MATER

Three years ago, the authors set up a project to provide graphical user interfaces (GUI) for visualization and analysis of oceanographic data. At that time, Interactive Data Language (IDL) from the Research Systems Inc., was chosen as the programming language to build the software. However, the need to purchase a license of the IDL environment prevented people from using such tools. This has severely limited the diffusion, utility and portability of the authors' project. The solution to overcome this problem has been to adapt their tools into a Web based environment. They describe the structure of their system that allows any user to make visualization and to perform analysis of data through the network. Briefly, data and IDL engine are hosted in a Web server and clients receive the output as a Web page with graphics. Thus any researcher may perform its own analysis or visualization without the need of having to additionally license the IDL package. The major difficulty they have found has been the interaction between the Web server and the IDL-written routines. The Object Oriented Programming capabilities of the recent ION-IDL have been a key point, because the tools are executed from very simple IDL batch files. As an interesting application they also describe the integration of their system into a ship data acquisition network during a field experiment. They show the case of the MATER-3 cruise where they could visualize any kind of data in almost real-time with the help of a unique workstation. At present, their system can only work with data visualization but the implementation for data analysis is undergoing straightforward.