Influence of the NAO on the northwestern Mediterranean wave climate

RESUMEN. Influencia de la nao en el clima marítimo del Mediterráneo noroccidental. – El presente trabajo estudia las teleconexiones entre la Oscilación del Atlántico Norte (NAO ) y el clima marítimo en el Mediterráneo noroccidental, definido por la media mensual de la altura significante (SWH) y la media mensual de la altura significante correspondiente al percentil 95 (percentil 95 SWH), en el período comprendido entre 1958 y 2001. Los datos analizados corresponden al retroanálisis de 44 años de datos atmosféricos, dentro del marco del proyecto HIPOCAS . Estos datos han sido codificados en forma de EOF s para obtener la variabilidad espacio-temporal asociada a la NAO . Los datos utilizados han sido previamente blanqueados para evitar correlaciones ficticias entre las series, mediante el ajuste a un modelo autorregresivo de orden p. Los resultados muestran como el clima marítimo del Mediterráneo noroccidental está influenciado a escala mensual por las distintas fases de la NAO . Cuando la NAO está en su fase positiva, podemos observar anomalías positivas en la altura significante media mensual, así como en la altura de ola correspondiente al percentil 95, estas anomalías aparecen en la zona comprendida entre las Islas Baleares, el Golfo de León y la costa catalana.ABSTRACT. This study examines teleconnections between the North Atlantic Oscillation (NAO ) and the wave climate of the northwestern Mediterranean Sea (NWM), defined by the monthly mean significant wave height (SWH) and the 95th percentile significant wave height (95th percentile SWH), in the period ranging from 1958 to 2001. The data analyzed comes from the multidecadal hindcast over Europe carried out during the HIPOCAS project. In order to avoid fictitious cross-correlations, data were prewhitened by fitting a p-order autoregressive model. To split the temporal and spatial variability, an EOF encoding technique was applied to residuals before searching for teleconnections. We found the northwestern Mediterranean wave climate to be influenced by the North Atlantic Oscillation (NAO ) with an instantaneous response. When the NAO is in its positive phase, positive anomalies in the SWH and the 95th percentile SWH appear in the area between the Balearic Islands, the Gulf of Lions and the Catalonian coast

A simple model of a water column applied to the deep water formation in the Northern Catalan Sea

In this paper an attempt to reproduce the evolution of the thermal structure of water columns by a simple one-dimensional model is presented. The model is based on the heat balance between the sea and the atmosphere and it is specially sensitive to air temperature and wind speed. The model is used to study the influence of these atmospheric forcings on the deep water formation process in the Northern Catalan Sea. It is applied using meteorological and oceanographic data collected during the ALPEX Special Observation Period (SOP) and the results are compared to temperature profiles obtained during the CARON 82 cruise (MEDALPEX)Publicado

Las playas de Menorca: naturaleza y distribución

[spa]La costa de Menorca acoge 114 sistemas de playa que representan el 9,9% de la línea de costa de Menorca. Ubicadas en un ambiente micromareal y expuestas a oleajes que raras veces superan los 3m de altura significante, la mayoría de las playas menorquinas se caracterizan por presentar arenas biogénicas de medias a gruesas, estando su distribución y naturaleza condicionadas, principalmente, por el contexto morfoestructural de la isla. Tanto en lo tocante a la configuración fisiográfica de las playas y su espacio de acomodación como a la naturaleza y tipología del sedimento. En general, la tasa de evolución media de las playas de Menorca no presenta grandes problemas y se caracteriza por la estabilidad, una estabilidad reforzada por el carácter protegido o semi-protegido de las ensenadas que acogen a las playas o porque las playas más expuestas coinciden las acumulaciones de cantos y bloques al pie de acantilados[eng]The Menorcan coast contains 114 beach systems, which occupy 9,9% of the coastline. Menorcan beaches are characterized by a microtidal and a moderate wave energy environment where, at annual scale, in few occasions significant wave heights attend values larger than 3m. Biogenic medium to coarse sands beaches are the dominant feature, although the island morphostructure controls both: the type of beach and the sediment nature and/or texture. In average, the shoreline change rate for the island beaches shows a stability scenario reinforced by the large number of embayed and pocket beaches along the Menorcan coast. The beaches exposed to the most energetic waves tend show cobble-boulder beaches at the cliff-toe

Autonomous underwater gliders monitoring variability at "choke points" in our ocean system: a case study in Western Mediterranean Sea

Publicado

Fixed and drifting buoys around the national Spanish waters

Joint Technical Commission for Oceanography and Marine Meteorology (JCOMM) Marine Technical Conference, The Technical Conference (TECO) Toward an Integrated Met-ocean Monitoring, Forecasting and Services System, 25-29 October 2017, Geneva, SwitzerlandImproving the knowledge of the ocean and seas surrounding the Iberian Peninsula and Balearic and Canary islands is an objective of the Spanish oceanography. For that purpose, a number of fixed and drifting floats have been established in the last 25 years. Data buoys measure sea surface temperature and salinity, ocean current velocity, air temperature, humidity, wave characteristic and wind velocity across seas and ocean. The objective is increase the quantity, quality, coverage and timeliness of atmospheric and oceanographic data. These observations are used immediately to improve forecast and therefore increase marine safety. The main group of fixed buoys is formed by the Puertos del Estado deep and shallow buoy networks, but a series of well instrumented new platforms has been established in later times. The RAIA Project (Xunta de Galicia), PLOCAN, SOCIB, IEO, Euskalmet-AZTI, ICM and UTM (CSIC) and University and Polytechnic of Barcelona have completed the Observing System. Most of the buoys are transmitting data by GTS for using in atmospheric and ocean prediction models. Multidisciplinary sensors as Dissolved Oxygen, Fluorescence Chlorophyll or pCO2 has been mounted in the buoys and calibration/validation procedures has been developed for improve data quality. Antifouling systems recently developed have also been included and quality of the optical sensors measurements has improved. Drifting floats has increase its number and importance, from Argo floats to traditional deriving ones improving the Spanish contribution to IOC and WWO and JCOMM. Spain is member of EuroArgo ERIC. SOCIB and IEO are the main contributors. Also multidisciplinary work has been done associated to Argo buoys. BGQ ARGO incorporate O2 sensor. ICM, SMOS Barcelona Expert Center, and SOCIB are the main contributors to the drifting buoys group. Main objectives are improving Technological development as well as data management. Tropical and Southern Atlantic Ocean are the main studying areasPeer Reviewe

A new Mean Dynamic Topography of the Mediterranean Sea based on model outputs, drifter data, hydrological profiles and altimeter measurements

Trabajo presentado en la EGU General Assemby 2013, celebrada del 7 al 12 de abril de 2013 en Viena (Austria)Peer Reviewe

Neurofilament light chain level is a weak risk factor for the development of MS

Altres ajuts: T Jens Kuhle was supported by an ECTRIMS Research Fellowship Programme and by the Forschungsfonds of the University of Basel, Switzerland.To determine the prognostic value of selected biomarkers in clinically isolated syndromes (CIS) for conversion to multiple sclerosis (MS) and disability accrual. Data were acquired from 2 CIS cohorts. The screening phase evaluated patients developing clinically definite MS (CIS-CDMS) and patients who remained as CIS during a 2-year minimum follow-up (CIS-CIS). We determined levels of neurofascin, semaphorin 3A, fetuin A, glial fibrillary acidic protein, and neurofilament light (NfL) and heavy chains in CSF (estimated mean [95% confidence interval; CI]). We evaluated associations between biomarker levels, conversion, disability, and magnetic resonance parameters. In the replication phase, we determined NfL levels (n = 155) using a 900 ng/L cutoff. Primary endpoints in uni- and multivariate analyses were CDMS and 2010 McDonald MS. The only biomarker showing significant differences in the screening was NfL (CIS-CDMS 1,553.1 [1,208.7-1,897.5] ng/L and CIS-CIS 499.0 [168.8-829.2] ng/L, p < 0.0001). The strongest associations were with brain parenchymal fraction change (r = −0.892) and percentage brain volume change (r = −0.842) at 5 years. NfL did not correlate with disability. In the replication phase, more NfL-positive patients, according to the cutoff, evolved to MS. Every 100-ng/L increase in NfL predicted CDMS (hazard ratio [HR] = 1.009, 95% CI 1.005-1.014) and McDonald MS (HR = 1.009, 95% CI 1.005-1.013), remaining significant for CDMS in the multivariate analysis (adjusted HR = 1.005, 95% CI 1.000-1.011). This risk was lower than the presence of oligoclonal bands or T2 lesions. NfL is a weak independent risk factor for MS. Its role as an axonal damage biomarker may be more relevant as suggested by its association with medium-term brain volume changes

Terms of reference for the mediterranean tuna habitat observatory initiative

[EN] We present the Terms of Reference for a case study on a Mediterranean eco-region focusing on the environmental component of the Ecosystem Report Card. The objective of this case study is to describe and monitor the variability of environmental processes in the Mediterranean Sea that affect the ecology of large pelagic fishes, with a particular attention on tunas, and the possible role of climate change on this variability. Here we define the objectives and activities of the initiative, the participant roles, primary indicators and the methodological approach[FR] Ce document présente les termes de référence d’une étude de cas sur une écorégion méditerranéenne consacrée à la composante environnementale de la fiche informative sur les écosystèmes. L'objectif de cette étude de cas est de décrire et de suivre la variabilité des processus environnementaux en mer Méditerranée qui affectent l'écologie des grands poissons pélagiques, en accordant une attention particulière aux thonidés, et de déterminer le rôle possible du changement climatique sur cette variabilité. Nous définissons ici les objectifs et les activités de l'initiative, les rôles des participants, les indicateurs primaires et l'approche méthodologique.[ES] En el documento se presentan los términos de referencia para un estudio de caso sobre una ecorregión mediterránea centrado en el componente medioambiental de la ficha informativa sobre ecosistemas. El objetivo de este estudio de caso es describir y hacer un seguimiento de la variabilidad de los procesos medioambientales en el mar Mediterráneo que afectan a la ecología de los grandes peces pelágicos, con especial atención a los túnidos, y el posible papel del cambio climático en esta variabilidad. A continuación, se definen los objetivos y actividades de la iniciativa, las funciones de los participantes, los indicadores principales y el enfoque metodológico.Peer reviewe