Análisis multiparamétrico y validación de tres simulaciones globales en el Mediterráneo occidental

We analyse a hierarchy of three 1/4° global numerical simulations (ORCA-025.G70 (G70), ORCA-025.G85 (G85) and GLORYS1V1 (GLORYS)) by assessing their performance against observational data in the western Mediterranean. When compared with the EN3_v2a temperature and salinity database, the simulations are capable of reproducing surface layer temperature interannual variability but G70 is inaccurate with intermediate and deep-layer trends. This aspect is improved by the increased vertical resolution of G85 and by data assimilation in GLORYS. Salinity is the most problematic parameter because of the imbalance of the freshwater budget derived from inaccuracies in the atmospheric forcing parameters. Surface salinity restoring is needed in order to avoid salinity drift and inaccurate sea-level trends. G70, with a stronger relaxation, has a lower trend closer to altimetric measurements than G85. Mean surface circulation is well reproduced for relatively large-scale signals. We further show that G85 and GLORYS provide evidence of the 2004-2005 and 2005-2006 deep convection events in the Gulf of Lion. Finally, transports through the main straits of the western Mediterranean are correct in order of magnitude, direction and seasonal cycle when compared with observations. This study contributes to the improvement of the ORCA hierarchy of simulations and points out the strengths and weaknesses of these simulations in the Mediterranean Sea.Analizamos un conjunto de tres simulaciones numéricas globales de 1/4º (ORCA-025.G70 (G70), ORCA-025.G85 (G85) y GLORYS1V1 (GLORYS)) comparándolas con datos observacionales en el Mediterráneo Occidental (WMED). Contrastando con la base de datos de temperatura y salinidad EN3_v2a las simulaciones son capaces de reproducir la variabilidad superficial en temperatura sin embargo G70 exagera las tendencias en capas intermedias y profundas. Este aspecto es mejorado por la mayor resolución vertical de G85 y la asimilación de datos de GLORYS. La salinidad es el parámetro más problemático debido al desequilibrio del balance de agua dulce procedente de imprecisiones en los parámetros de forzamiento atmosférico. Relajación de salinidad superficial es necesaria para evitar derivas de salinidad y nivel del mar. De hecho G70 con su relajación más intensa tiene una tendencia más baja (y más cercana a mediciones altimétricas) que G85. La circulación promedio en superficie está bien reproducida para señales relativamente grandes. Además, demostramos que G85 y GLORYS muestran evidencia de los eventos de convección profunda de 2004-2005 y 2005-2006 en el Golfo de León. Finalmente, transportes a través de los principales canales y estrechos del Mediterráneo Occidental son correctos cuando se comparan con observaciones, tanto en orden de magnitud y dirección, como en el ciclo estacional. Este estudio contribuye a la mejora del conjunto de simulaciones ORCA y señala las fortalezas y debilidades de estas simulaciones en el Mar Mediterráneo

SOCIB: the impact of new marine infrastructures in understanding and forecasting the coastal oceans: some examples from the Balearic Islands in the Mediterranean Sea

New monitoring technologies are being progressively implemented in coastal ocean observatories. As an example, gliders allow high resolution sampling, showing the existence of new features, such as submesoscale eddies with intense vertical motions that significantly affect upper ocean biogeochemical exchanges, an issue of worldwide relevance in a climate change context. SOCIB, is one of such systems, a new facility of facilities (covering from the coast to the open sea, and including among others a nearshore beach monitoring facility, HF radar, gliders and AUV’s, moorings, satellite, drifters and ARGO profilers, modelling), a scientific and technological infrastructure which is providing free, open, quality controlled and timely streams of oceanographic and coastal data and also modelling services. SOCIB takes profit of the strategic position of the Balearic Island at the Atlantic/Mediterranean transition area, one of the ‘hot spots’ of biodiversity in the world’s oceans. As an example of on-going SOCIB operations, since January 2011 sustained glider operations are in place in the Ibiza and Mallorca channels. The data centre is the core of SOCIB. The data management system created for gliders is an example of the new informatics capabilities for real time definition of mission planning, including adaptive sampling and real time monitoring using a Web tool that allows quick visualization and download. This type of new infrastructures, combined with new technologies and careful scientific analysis will allow new ways of international cooperation leading to major science breakthroughs in the very near future and new ways of science based coastal and ocean management.Peer Reviewe

Analysis of Mediterranean ocean variability using five numerical simulations

Peer Reviewe

Analysis of a 44-year hindcast for the Mediterranean Sea: comparison with altimetry and in situ observations

19 páginas, 10 figuras, 2 tablas.[EN]We study the interannual and seasonal variability in the Mediterranean Sea over the period 1958-2004 by comparing a numerical simulation (the 1/4º ORCA-R025 G70 model run, ‘ORCA’ hereafter) with altimetry and the MEDAR temperature and salinity database. The model is forced by the ERA40 atmospheric forcing and has a salinity restoring term applied at surface. Comparing temperature between ORCA and MEDAR shows good interannual variability agreement (correlations of ~0.8 in the western Mediterranean and ~0.5 in the eastern Mediterranean) at surface layers (0-150 m), but slightly higher mean values in the model (0.08-0.16°C). The salinity analysis shows that the surface salinity restoring term has obliterated most of the interannual variability. Mean surface salinities are slightly lower in the model (~0.3), replicated in deeper layers to a lesser degree, and could mean that the restoring term applies insufficient evaporation to compensate for a weak atmospheric forcing (ERA40) water loss flux. The sea level analysis comparing sea surface height (SSH) and steric height from ORCA and sea level anomalies from altimetry (1993-2004) shows good correlations (~0.8) in the interannual variability and annual cycle. However, the model’s SSH overestimates (~15 mm/yr) observed positive altimetric trends (~3-4 mm/yr). In an attempt to identify the source of this overestimation, a water budget calculation was performed between the horizontal and vertical water fluxes in the Mediterranean Sea. Horizontal transport through the main straits shows appropriate values when compared to observations. Thus, the cause of the exaggerated SSH trend is probably a water flux imbalance. By improving surface salinity restoring and atmospheric forcing, the ORCA simulations can provide very promising tools for studies of interannual variability in the Mediterranean Sea.[ES]Evaluación de un retroanálisis de 44 años para el mar Mediterráneo: comparación con altimetría y observaciones in situ. – Estudiamos la variabilidad estacional e interanual en el mar Mediterráneo durante el periodo 1958-2004, comparando una simulación numérica (la simulación de 1/4º ORCA-R025 G70, ‘ORCA’ de ahora en adelante) con datos de altimetría, y temperatura y salinidad (MEDAR). El modelo utiliza el forzamiento atmosférico ERA40 y tiene aplicado un término de relajación a la salinidad en superficie. La comparación de temperatura entre ORCA y MEDAR muestra un buen acuerdo de la variabilidad interanual (correlación ~0.8 en el Mediterráneo Occidental (WMED), ~0.5 en el Mediterráneo Oriental (EMED)) en las capas superficiales (0-150 m), pero con valores medios ligeramente superiores en el modelo (0.08-0.16ºC). El análisis de salinidad muestra que la mayor parte de la variabilidad en superficie ha sido destruida por el término de relajación. Las salinidades medias en superficie son ligeramente inferiores en el modelo (~0.3), lo cual se repite en capas más profundas pero en menor grado. Esto podría significar que el término de relajación no aplica suficiente evaporación para compensar un débil flujo de pérdida de agua en el forzamiento atmosférico (ERA 40). El análisis de altura de nivel del mar (SSH) y altura estérica (SH) del modelo ORCA y anomalía del nivel del mar proveniente de la altimetría (1993-2004) muestra buenas correlaciones (~0.8) en la variabilidad interanual y ciclo estacional. Sin embargo la SSH del modelo sobreestima (~15 mm/año) la tendencia positiva observada por la altimetría (~3-4 mm/año). En un intento de identificar el origen de esta sobreestimación, se hizo un cálculo de balance de masas entre los flujos horizontales y verticales (E-P-R) que entran al mar Mediterráneo. Los flujos horizontales a través de los principales estrechos muestran valores adecuados cuando se comparan con observaciones. Por lo tanto, la exagerada tendencia en SSH del modelo es probablemente debido a un desequilibrio entre la E-P-R (evaporación, precipitación y aporte fluvial). Mejorando el término de relajación de salinidad y el forzamiento atmosférico, las simulaciones ORCA pueden proporcionar unas herramientas muy prometedoras para estudios de variabilidad interanual en el mar Mediterráneo.Peer reviewe

Análisis multiparamétrico y validación de tres simulaciones globales en el Mediterráneo occidental

We analyse a hierarchy of three 1/4° global numerical simulations (ORCA-025.G70 (G70), ORCA-025.G85 (G85) and GLORYS1V1 (GLORYS)) by assessing their performance against observational data in the western Mediterranean. When compared with the EN3_v2a temperature and salinity database, the simulations are capable of reproducing surface layer temperature interannual variability but G70 is inaccurate with intermediate and deep-layer trends. This aspect is improved by the increased vertical resolution of G85 and by data assimilation in GLORYS. Salinity is the most problematic parameter because of the imbalance of the freshwater budget derived from inaccuracies in the atmospheric forcing parameters. Surface salinity restoring is needed in order to avoid salinity drift and inaccurate sea-level trends. G70, with a stronger relaxation, has a lower trend closer to altimetric measurements than G85. Mean surface circulation is well reproduced for relatively large-scale signals. We further show that G85 and GLORYS provide evidence of the 2004-2005 and 2005-2006 deep convection events in the Gulf of Lion. Finally, transports through the main straits of the western Mediterranean are correct in order of magnitude, direction and seasonal cycle when compared with observations. This study contributes to the improvement of the ORCA hierarchy of simulations and points out the strengths and weaknesses of these simulations in the Mediterranean Sea.We would like to thank the DRAKKAR Group and MERCATOR-Océan for providing the simulations analysed in this study. The first author would like to give special thanks to the CSIC I3P PreDoc Grant Programme for financing his PhD thesis work, as well as to the MyOcean FP7 EU Project for making part of this study possible. The altimeter products were produced by SSALTO/DUACS and distributed by AVISO with support from CNES. We would also like to acknowledge the work by the Hadley Centre in creating the EN3 dataset.Peer Reviewe

Multiparametric Analysis & Validation in the Mediterranean of 4 Eddy Permitting Global OGCMs of Past Decades

Trabajo presentado en el I Encuentro de la Oceanografía Física Española, celebrado en Barcelona, España, del 13 al 15 de octubre de 2010Peer Reviewe

Matching genetics with oceanography: Directional gene flow in a Mediterranean fish species

Genetic connectivity and geographic fragmentation are two opposing mechanisms determining the population structure of species. While the first homogenizes the genetic background across populations the second one allows their differentiation. Therefore, knowledge of processes affecting dispersal of marine organisms is crucial to understand their genetic distribution patterns and for the effective management of their populations. In this study, we use genetic analyses of eleven microsatellites in combination with oceanographic satellite and dispersal simulation data to determine distribution patterns for Serranus cabrilla, a ubiquitous demersal broadcast spawner, in the Mediterranean Sea. Pairwise population FST values ranged between -0.003 and 0.135. Two genetically distinct clusters were identified, with a clear division located between the oceanographic discontinuities at the Ibiza Channel (IC) and the Almeria-Oran Front (AOF), revealing an admixed population in between. The Balearic Front (BF) also appeared to dictate population structure. Directional gene flow on the Spanish coast was observed as S. cabrilla dispersed from west to east over the AOF, from north to south on the IC and from south of the IC towards the Balearic Islands. Correlations between genetic and oceanographic data were highly significant. Seasonal changes in current patterns and the relationship between ocean circulation patterns and spawning season may also play an important role in population structure around oceanographic fronts. © 2011 Blackwell Publishing Ltd.Peer Reviewe

New method for restoring degraded Cystoseira forests

Trabajo presentado en el 6th European Phycological Congress, celebrado en Londres, Reino Unido, del 23 al 28 de agosto de 2015Peer Reviewe

Multiparametric analysis and validation in the Mediterranean of 4 eddy-permitting global OGCM hindcasts of past decades

We analyze a hierarchy of three 1/4º global numerical simulations (ORCA-025 G70, ORCA-025 G85 and GLORYS1V1) by assessing their performance against observational data in the Western Mediterranean (WMED). When compared to the EN3_v2a temperature and salinity database the simulations are capable of reproducing surface layer temperature interannual variability but G70 is inaccurate with intermediate and deep layer trends. This aspect is improved by the increased vertical resolution of G85 and by data assimilation in GLORYS1V1. Salinity is the most problematic parameter due to the imbalance of the freshwater budget derived from inaccuracies in the atmospheric forcing parameters. Surface salinity restoring is needed in order to avoid salinity drift and inaccurate sea level trends. Indeed, G70 with a stronger relaxation has a lower trend (and closer to altimetric measurements) than G85. Mean surface circulation is well reproduced for relatively large-scale signals. We further show that G85 and GLORYS provide evidence of the 2004-2005 and 2005-2006 deep convection events in the Gulf of Lions. Finally, transports through the main straits of the WMED are correct, both in order of magnitude, direction and seasonal cycle when compared to observations. This study contributes to the improvement of the ORCA hierarchy of simulations and points out the strengths and weaknesses of these simulations in the Mediterranean Sea. We also include the higher resolution (1/8º) simulation NEMOMED8 (Beuvier et al. (2010)) focusing on the Balearic Sea and combining the simulation data with satellite data (sst and altimetry both gridded and along-track), drifters and hydrographic data (CTDs and gliders). The study is be centered around the physical characterization of the Balearic Sea, the study of the heat and water fluxes passing through that area, taking special note on fluxes through the Balearic Channels.Peer Reviewe