The ESEAS-RI Sea Level Test Station: Reliability and Accuracy of Different Tide Gauges

In December 2002 a test station of six tide gauges using four different technologies (acoustic, pressure, pulse radar and FMCW radar) was established by Puertos del Estado at the port of Vilagarcfa de Arousa (NW Spain), as part of the ESEAS-RI (European Sea Level Service- Research & Infrastructure) project. The aim was to compare the performance of the tide gauges in order to support the future decisions concerning the improving of the sea level observing systems. Although the comparison of the sea level time series showed that all the tide gauges met GLOSS (Global Sea Level Observing System) quality standards, the experiment also revealed some differences in the quality of the data for certain ranges of frequency.En diciembre de 2002, y como parte del proyecto europeo ESEAS-RI (European Sea Level Service Research&lnfrastructure), Puertos del Estado instalô una estaciôn piloto de seis mareôgrafos de tecnologîas diferentes (acustica, de presiôn, radar de pulso y radar de barrido de frecuencias) en el puerto de Vilagarcia de Arousa (NO Espaha). El objetivo era comparar el funcionamiento de los mareôgrafos con el fin de apoyar decisiones futuras concernientes a la mejora de las redes de medida del nivel del mar. A pesar de que las comparaciones realizadas con las series temporales de nivel del mar mostraron que todos los equipos satisfacen los requerimientos exigidos por GLOSS (Global Sea Level Observing System), el experimento también revelô algunas diferencias en la calidad de los datos para ciertos rangos de frecuencia.En décembre 2002, dans le cadre du projet européen ESEAS-RI (European Sea Level Service Research&lnfrastructure), une station pilote de six marégraphes utilisant quatre technologies différentes (acoustique, à pression, radar par impulsions et radar à onde entretenue modulée en fréquence) a été installée par Puertos del Estado au port de Vilagarcîa de Arousa (NO de l ’Espagne). L’objectif était de comparer le fonctionnement des marégraphes afin de soutenir les futures décisions relatives à l ’amélioration des systèmes d’observation du niveau de la mer. Bien que la comparaison des séries chronologiques du niveau de la mer ait montré que tous les marégraphes satisfont aux normes de qualité GLOSS (Système mondial d’observation du niveau de la mer), l ’expérience a également mis en lumière certaines différences dans la qualité des données pour certaines gammes de fréquence

Water renewal mechanisms of the Bay of Algeciras in the Strait of Gibraltar

The Bay of Algeciras (BA) is a marine environment subject to high levels of anthropogenic pressure. Here we analyze observations collected at the Bay and the results of an ocean circulation model to investigate its circulation and variability. Special attention is paid to the identification of the mechanisms enhancing the exchange of water with the adjacent Strait of Gibraltar and therefore contributing to maintain satisfactory levels of water quality.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

What does cause the collapse of the western Alboran gyre?

The stability of the Western Alboran Gyre (WAG) is investigated on the basis of the outputs of a state-of-the-art Operational Oceanography System of the Strait of Gibraltar and the Alboran Sea. The system is based on a high-resolution (up to 500 m within Gibraltar) primitive-equation circulation model (MIT General Circulation Model) nested to a larger-scale model of the Mediterranean Sea. It is forced by tides and atmospheric (momentum, heat, and fresh water) fluxes provided by the Spanish meteorological Agency. Satellite and model SST corresponding to a hindcast run of Autumn 2011 show the classical circulation of the Alboran Sea at the beginning of October, characterized by the presence of two well developed anticyclonic gyres with the Atlantic jet flowing north-east at the exit of the strait to surround the WAG. This configuration breaks down within a time-scale of three weeks. In a first stage, the WAG undergoes a noticeable weakening and moves slightly to the east. This, in turn, makes possible the (natural) southward veering of the Atlantic jet and the formation of a new gyre on the African coast. It is shown that the WAG perturbations that triggers the sequence is produced by an event of vortex-vortex interaction between the WAG and a cyclonic gyre generated between the Atlantic Jet and Spanish coast. The development of the cyclonic gyre is explained in terms of the advection of tidally-induced positive shear vorticity generated near the lateral boundaries of the Strait of Gibraltar.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Modelo hidrodinámico de alta resolución del puerto de Algeciras – proyecto SAMPA2

El proyecto SAMPA, financiado por la Autoridad Portuaria de la Bahía de Algeciras (APBA) y Puertos del Estado entre los años 2010 y 2013, fue proyecto piloto para la integración de un modelo numérico de alta resolución en un sistema operacional en el cual el Grupo de Oceanografía Física de la Universidad de Málaga (GOFIMA) desarrolló el propio modelo hidrodinámico [Sammartino et al., 2014; Sánchez Garrido et al., 2014]. Los productos operacionales servidos por Puertos del Estado (portal PORTUS) y la APBA (sistema CMA), alimentados entre otros por las predicciones derivadas de SAMPA, representaron el primer ejemplo de difusión de un forecast océano-meteorológico accesible tanto al público generalizado como al personal técnico marítimo empleado en el puerto. El modelo numérico que estaba detrás de SAMPA, sin embargo, no tenía suficiente resolución para llegar a resolver la dinámica portuaria, y la APBA, en el 2015, financió la segunda generación del proyecto (SAMPA2), con el objetivo de cubrir ese hueco. Entre la segunda mitad del 2015 y durante todo el 2016, después de haber realizado un atento análisis de los aspectos mejorables del actual SAMPA, GOFIMA desarrolló un sistema completamente nuevo: un modelo anidado en tres dominios acoplados, que proporciona un aumento progresivo de resolución desde la escala regional hasta la portuaria. A eso se añade el valor añadido de unas herramientas de análisis de calidad de agua del Puerto de Algeciras de acuerdo con las indicaciones de la ROM5.1-13.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

A numerical model analysis of the tidal flows in the Bay of Algeciras, Strait of Gibraltar

A numerical model has been applied to study the tidal flows of the Bay of Algeciras in the eastern part of the Strait of Gibraltar, focusing on the M-2 semidiurnal constituent. The numerical model was satisfactorily validated against a comprehensive set of observations collected in the bay in the year 2011 and the model outputs were used for a detailed analysis of the local tidal circulation. The M-2 net (vertically integrated) transport across the mouth of the bay has an amplitude of 2.7 x 10(-3) Sv, while that of the sea surface signal is of similar to 30 cm and is in quadrature with this flow. However, the vertically integrated flow is the result of a pronounced baroclinic structure consisting of an upper (S 37.5) layers, whose associated transports are one order of magnitude higher. This reveals a noticeable internal tide that is characterized by an inward (to the head of the bay) propagation and a likely quarter-wave resonance. During the rising tide, Atlantic water from the strait comes in and produces the thickening of the upper (Atlantic) layer in the bay, while Mediterranean water of the lower layer is pushed out to join the Mediterranean water stream that is flowing to the west along the Strait of Gibraltar. During the falling tide, Atlantic water flows out of the bay and incorporates to the eastward flow in the strait. In this tidal phase, Mediterranean water flows into the bay. Therefore, Atlantic and Mediterranean waters accumulate in the bay during the rising and falling tide, respectively. This pattern is opposite to that observed in the strait, where the Mediterranean layer thickens during the rising tide and becomes thinner during the falling tide. This suggests that the internal tide in the bay is basically determined by the baroclinic forcing at its mouth imposed by the baroclinic tide of the Strait of Gibralta

CMEMS downscaled wave operational forecast system

This document describes the numerical modelling work for waves done in wp5.2. needed to implement OSPA

Final version of the software running operationally for the demonstration

This report includes the description and the manuals (both at User and Administrator level) for the OSPAC service and its application

Mediterranean Sea response to climate change in an ensemble of twenty first century scenarios

The Mediterranean climate is expected to become warmer and drier during the twenty-first century. Mediterranean Sea response to climate change could be modulated by the choice of the socio-economic scenario as well as the choice of the boundary conditions mainly the Atlantic hydrography, the river runoff and the atmospheric fluxes. To assess and quantify the sensitivity of the Mediterranean Sea to the twenty-first century climate change, a set of numerical experiments was carried out with the regional ocean model NEMOMED8 set up for the Mediterranean Sea. The model is forced by air–sea fluxes derived from the regional climate model ARPEGE-Climate at a 50-km horizontal resolution. Historical simulations representing the climate of the period 1961–2000 were run to obtain a reference state. From this baseline, various sensitivity experiments were performed for the period 2001–2099, following different socio-economic scenarios based on the Special Report on Emissions Scenarios. For the A2 scenario, the main three boundary forcings (river runoff, near-Atlantic water hydrography and air–sea fluxes) were changed one by one to better identify the role of each forcing in the way the ocean responds to climate change. In two additional simulations (A1B, B1), the scenario is changed, allowing to quantify the socio-economic uncertainty. Our 6-member scenario simulations display a warming and saltening of the Mediterranean. For the 2070–2099 period compared to 1961–1990, the sea surface temperature anomalies range from +1.73 to +2.97 °C and the SSS anomalies spread from +0.48 to +0.89. In most of the cases, we found that the future Mediterranean thermohaline circulation (MTHC) tends to reach a situation similar to the eastern Mediterranean Transient. However, this response is varying depending on the chosen boundary conditions and socio-economic scenarios. Our numerical experiments suggest that the choice of the near-Atlantic surface water evolution, which is very uncertain in General Circulation Models, has the largest impact on the evolution of the Mediterranean water masses, followed by the choice of the socio-economic scenario. The choice of river runoff and atmospheric forcing both have a smaller impact. The state of the MTHC during the historical period is found to have a large influence on the transfer of surface anomalies toward depth. Besides, subsurface currents are substantially modified in the Ionian Sea and the Balearic region. Finally, the response of thermosteric sea level ranges from +34 to +49 cm (2070–2099 vs. 1961–1990), mainly depending on the Atlantic forcing

EuroGOOS roadmap for operational coastal downstream services

The EuroGOOS Coastal working group examines the entire coastal value chain from coastal observations to services for coastal users. The main objective of the working group is to review the status quo, identify gaps and future steps needed to secure and improve the sustainability of the European coastal service provision. Within this framework, our white paper defines a EuroGOOS roadmap for sustained “community coastal downstream service” provision, provided by a broad EuroGOOS community with focus on the national and local scale services. After defining the coastal services in this context, we describe the main components of coastal service provision and explore community benefits and requirements through sectoral examples (aquaculture, coastal tourism, renewable energy, port, cross-sectoral) together with the main challenges and barriers to user uptake. Technology integration challenges are outlined with respect to multiparameter observations, multi-platform observations, the land-coast-ocean continuum, and multidisciplinary data integration. Finally, the technological, financial, and institutional sustainability of coastal observing and coastal service provision are discussed. The paper gives special attention to the delineation of upstream and downstream services, public-private partnerships and the important role of Copernicus in better covering the coastal zone. Therefore, our white paper is a policy and practice review providing a comprehensive overview, in-depth discussion and actionable recommendations (according to key short-term or medium-term priorities) on the envisaged elements of a roadmap for sustained coastal service provision. EuroGOOS, as an entity that unites European national operational oceanography centres, research institutes and scientists across various domains within the broader field of operational oceanography, offers to be the engine and intermediary for the knowledge transfer and communication of experiences, best practices and information, not only amongst its members, but also amongst the different (research) infrastructures, institutes and agencies that have interests in coastal oceanography in Europe

The Copernicus Marine Environment Monitoring Service Ocean State Report

The Copernicus Marine Environment Monitoring Service (CMEMS) Ocean State Report (OSR) provides an annual report of the state of the global ocean and European regional seas for policy and decision-makers with the additional aim of increasing general public awareness about the status of, and changes in, the marine environment. The CMEMS OSR draws on expert analysis and provides a 3-D view (through reanalysis systems), a view from above (through remote-sensing data) and a direct view of the interior (through in situ measurements) of the global ocean and the European regional seas. The report is based on the unique CMEMS monitoring capabilities of the blue (hydrography, currents), white (sea ice) and green (e.g. Chlorophyll) marine environment. This first issue of the CMEMS OSR provides guidance on Essential Variables, large-scale changes and specific events related to the physical ocean state over the period 1993–2015. Principal findings of this first CMEMS OSR show a significant increase in global and regional sea levels, thermosteric expansion, ocean heat content, sea surface temperature and Antarctic sea ice extent and conversely a decrease in Arctic sea ice extent during the 1993–2015 period. During the year 2015 exceptionally strong large-scale changes were monitored such as, for example, a strong El Niño Southern Oscillation, a high frequency of extreme storms and sea level events in specific regions in addition to areas of high sea level and harmful algae blooms. At the same time, some areas in the Arctic Ocean experienced exceptionally low sea ice extent and temperatures below average were observed in the North Atlantic Ocean