Atmospheric contribution to Mediterranean and nearby Atlantic sea level variability under different climate change scenarios

The contribution of atmospheric pressure and wind to the XXI century sea level variability in Southern Europe is explored under different climate change scenarios. The barotropic version of the HAMSOM model is forced with the output of the atmospheric ARPEGE model run under scenarios B1, A1B and A2. Additionally, a control simulation forced by observed SST, GHGs and aerosols concentrations for the period 1950-2000 and a hindcast forced by a dynamical downscalling of ERA40 for the period 1958-2001 are also run using the same models. The hindcast results have been validated against tide gauge observations showing good agreement with correlations around 0.8 and root mean square error of 3.2. cm. A careful comparison between the control simulation and the hindcast shows a reasonably good agreement between both runs in statistical terms, which points towards the reliability of the modelling system when it is forced only by GHG and aerosols concentrations. The results for the XXI century indicate a sea level decrease that would be especially strong in winter, with trends of up to - 0.8 ± 0.1. mm/year in the central Mediterranean under the A2 scenario. Trends in summer are small but positive (~. 0.05 ± 0.04. mm/yr), then leading to an increase in the amplitude of the seasonal cycle. The interannual variability also shows some changes, the most important being a widespread standard deviation increase of up to 40%. An increase in the frequency of positive phases of the NAO explains part of the winter negative trends. Also, an increase in the NAO variability would be responsible for the projected increase of the interannual variability of the atmospheric component of sea level. Conversely, the intra-annual variability (1-12. months excluding the seasonal cycle) does not show significant changes. © 2011 Elsevier B.V.This work has been carried out in the framework of the projects VANIMEDAT-2 (CTM2009-10163-C02-01, funded by the Spanish Marine Science and Technology Program and the E-Plan of the Spanish Government) and ESCENARIOS (funded by the Agencia Estatal de METeorología). Additional funding from the Platja de Palma Consortium is also acknowledged. G. Jordà acknowledges a “JAE-DOC” contract funded by the Spanish Research Council (CSIC).Peer Reviewe

Nivmar: a storm surge forecasting system for Spanish waters

In this paper, a storm surge prediction system for the Spanish Waters is presented. The system, named Nivmar, is based on the ocean circulation Hamsom model and on the harmonical prediction of tides computed from data measured by the tide gauge network Redmar, managed by Puertos del Estado. Nivmar is executed twice a day, running Hamsom forced by meteorological fields derived from the INM (Instituto Nacional de Meteorología) operational application of Hirlam atmospheric model. Data from Redmar tide gauges is used to to forecast the tidal elevations, to validate the system and to perform data assimilation, correcting systematic errors in the mean sea level due to physicals processes that are not included in the ocean model (i. e. steric height). The forecast horizon is 48 hours. In order to validate the system with measured data from Redmar a very stormy 5 months period was selected. Results from this test (November 95 to March 96) are presented. Data from this experiment shown that Nivmar is able to correctly predict sea level in the region. A simple data assimilation scheme for sea level is described and results from its application are studied. Finally, special focus is made in future plans and potential developments and applications of the system.No disponibl

Quality Assessment and Practical Interpretation of the Wave Parameters Estimated by HF Radars in NW Spain

High-frequency (HF) radars are efficient tools for measuring vast areas and gathering ocean parameters in real-time. However, the accuracy of their wave estimates is under analysis. This paper presents a new methodology for analyzing and validating the wave data estimated by two CODAR SeaSonde radars located on the Galician coast (NW Spain). Approximately one and a half years of wave data (January, 2014–April, 2015) were obtained for ten range cells employing two different sampling times used by the radar software. The resulting data were screened by an updated method, and their abundance and quality were described for each radar range cell and different wave regime; the latter were defined using the spectral significant wave height (Hm0) and mean wave direction (Dm) estimated by two buoys and three SIMAR points (SImulación MARina in Spanish, from the wave reanalysis model by Puertos del Estado (PdE)). The correlation between the results and the particularities of the different sea states (broadband or bimodal), the wind and the operation of the devices are discussed. Most HF radar wave parameters’ errors occur for waves from the NNE and higher than 6 m. The best agreement between the Vilán radar and the Vilano-Sisargas buoy wave data was obtained for the dominant wave regime (from the northwest) and the southwest wave regime. However, relevant contradictions regarding wave direction were detected. The possibilities of reducing the wave parameters’ processing time by one hour and increasing the numbers of range cells of the radars have been validatedThis research was funded by Interreg Atlantic Area project MyCOAST (EAPA 285/2016) and INTERREG V-A Spain-Portugal (POCTEP) project RADAR_ON_RAIA co-funded by the European Regional Development Fund (ERDF) (EU). V.P.-M. and A.B. acknowledge financial support by CRETUS strategic partnership (ED431E2018/01), co-funded by the ERDF (EU) http://www.usc.es/cretus/S

Improving operational ocean models for the Spanish Port Authorities: assessment of the SAMOA coastal forecasting service upgrades

The Puertos del Estado SAMOA coastal and port ocean forecast service delivers operational ocean forecasts to the Spanish Port Authorities since 01/2017 (originally set-up for 9 ports). In its second development phase (2019–2021), the SAMOA service has been extended to 31 ports (practically, the whole Spanish Port System). Besides, the next generation of the SAMOA service is being developed. Research is being focused on (1) updating atmospheric forcing (by combining the AEMET HARMONIE 2.5 Km forecasts and the IFS-ECMWF ones), (2) upgrading the circulation model (ROMS), and (3) testing new methodologies to nest SAMOA systems in the Copernicus IBI-MFC regional solution (with emphasis on its 3D hourly dataset). Evaluation of specific model upgrades is here presented. Model sensitivity tests have been assessed using the available in-situ and remoted sensed (i.e., RadarHF) observations. The results show that SAMOA outperforms IBI-MFC in sea level forecasting at meso- and macro-tidal environments. Improvements by the herein proposed upgrades are incremental: some of these set-ups were used in the last SAMOA operational releases (i.e., the SAM_INI and the SAM_ADV ones; the later currently in operations), whereas the latest test (SAM_H3D) ensures more nesting consistency with the IBI-MFC and improves significantly surface currents and sea-surface temperature simulations.The authors acknowledge support from the SAMOA-2 initiative (2018–2021), co-financed by Puertos del Estado (Spain) and the Spanish Port Authorities. This contribution has been conducted using E.U. Copernicus Marine Service Information. Specifically, from its NRT forecast products at the IBI area. Likewise, ocean in-situ and HF-radar observations from the Puertos del Estado monitoring network are also duly acknowledged.Peer ReviewedPostprint (published version

Predicción de la circulación marina en los puertos españoles

This paper describes the first harbour circulation forecasting system implemented in Spain. The configuration design was based on previous analyses of the morphologic and hydrodynamic behaviour of three harbours: Barcelona, Tarragona and Bilbao. A nested system of oceanic models was implemented, with a scope ranging from the regional scale (with a mean horizontal resolution of 5 km) to the harbour scale (with a mean horizontal resolution of 40 m). A set of sensitivity tests was carried out in order to determine the optimal configurations. The results of the operational system were compared with available observations, revealing that the intermediate models are able to reproduce the averaged hydrodynamic behaviour but not the spatio-temporal variability. With the harbour models the quality of the forecasts improves, reaching a correlation and RMSE of ~0.6 and 6 cm s–1, respectively, for Bilbao harbour. In addition, numerical experiments were carried out to evaluate the sensitivity of the forecasts to error sources. The results suggest that the errors in the information prescribed in the lateral boundary conditions are the most influential in the quality of the predictions. Errors in the wind field also have a smaller but non-negligible influence. Although the system is in the initial implementation phase and should be improved upon in the future, it is now a useful tool for harbour management. The predictions will be very helpful for harbour operations, pollution risk management and fighting oil spills.En este artículo se describe el primer sistema operacional de predicción de la circulación en puertos implementado en España. El diseño del sistema se ha basado en un análisis previo de las características hidrodinámicas y morfológicas de tres puertos de estudio: Barcelona, Tarragona y Bilbao. Se ha establecido un sistema de modelos oceánicos anidados que cubre desde la escala regional (con una resolución media horizontal de 5 km) al dominio portuario (con una resolución de 40 m). Diferentes experimentos de sensibilidad se han llevado a cabo para determinar las configuraciones óptimas. Los resultados del sistema operacional se han comparado con las observaciones disponibles, mostrando que los modelos intermedios son capaces de resolver el comportamiento hidrodinámico promedio, pero no la variabilidad espacio-temporal. En cuanto a los modelos portuarios, la calidad de las predicciones mejora, alcanzando una correlación y un RMSE de ~0.6 y 6 cm s–1, respectivamente, para el puerto de Bilbao. Adicionalmente se han realizado diferentes experimentos para determinar la sensibilidad del sistema a distintas fuentes de error. Los resultados sugieren que los errores en las condiciones de contorno laterales son los más determinantes sobre la calidad de las predicciones portuarias. Los errores en el viento, aun siendo menos importantes, son también considerables. Pese a ser un sistema que está en su fase inicial de implementación y que debe ser mejorado en el futuro, en su estado actual ya representa una herramienta útil para la gestión portuaria. Las predicciones de circulación serán de gran ayuda para la gestión de operaciones portuarias, riesgo de contaminación o control de vertidos

The MEDESS-GIB database: tracking the Atlantic water inflow

García Sotillo, Marcos ... et al.-- 9 pages, 5 figures, 2 tablesOn 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 CurrentThe 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 programPeer Reviewe

Ocean reanalyses

Ocean reanalyses are becoming increasingly available and useful, and may eventually attract a similar applications base as atmospheric reanalyses. Here we look at how they are being evaluated against both assimilated and independent data, and emphasise that circulation and transport estimates are critical. The Ocean Reanalysis Intercomparison project, ORA-IP, has been comparing many products for consistency on a regional and global basis, including ocean heat content, air-sea fluxes, and recently polar properties including sea ice. The Atlantic meridional overturning circulation as measured by the RAPID array at 26N, is now a challenging new target for simulation. This chapter shows that reanalyses may represent interior ocean basin circulations well (better than free-running models) but they still fail to consistently constrain boundary currents, where most meridional heat transport takes place. There is new work ongoing to try to physically interpret observation increments in reanalysis products, and to look at how to best develop long period reanalysis in earlier years when ocean observations were scarce. Finally, we look at new coupled ocean-atmosphere reanalysis that, by always maintaining a coupled ocean-atmospheric boundary layer, may lead to reduced assimilation increments and air-sea fluxes across domains

Evaluation of the operational CMEMS and coastal downstream ocean forecasting services during the storm Gloria (January 2020)

Storm Gloria was the 10th named storm in Europe for the 2019–2020 winter season, and it severely affected Spain and France. This powerful storm represents an excellent study case to analyze the capabilities of the different ocean model systems available in the Spanish Mediterranean coasts to simulate extreme events, as well as to assess their suitability to enhance preparedness in maritime disasters with high impacts on coastal areas. Five different operational ocean forecasting services able to predict the storm-induced ocean circulation are evaluated. Three of the systems are delivered by the Copernicus Marine Service (hereafter CMEMS): the CMEMS global scale solution (GLO-1/12°), the specific Mediterranean basin scale one (MED-1/24°), and the regional solution for the Atlantic façade (IBI-1/36°), which includes also part of the western Mediterranean. These CMEMS core products are complemented with two higher resolution models focused on more limited areas, which provide operational forecasts for coastal applications: the WMOP system developed at the Balearic Islands Coastal Observing and Forecasting System (SOCIB) with a horizontal resolution of roughly 2 km and the Puertos del Estado (PdE) SAMOA systems with a 350-m resolution that cover the coastal domains of the Spanish Port Authorities of Barcelona, Tarragona, Castellón and Almeria. Both the WMOP and SAMOA models are nested in CMEMS regional systems (MED and IBI, respectively) and constitute good examples of coastal-scale-oriented CMEMS downstream services. The skill of these five ocean models in reproducing the surface dynamics in the area during Gloria is evaluated using met-ocean in situ measurements from numerous buoys (moored in coastal and open waters) and coastal meteorological stations as a reference to track the effects of the storm in essential ocean variables such as surface current, water temperature, and salinity throughout January 2020. Furthermore, modeled surface dynamics are validated against hourly surface current fields from the two high-frequency radar systems available in the zone (the SOCIB HF-Radar system covering the eastern part of the Ibiza Channel and the PdE one at Tarragona, which covers the Ebro Delta, one of the coastal areas most impacted by Gloria). The results assess the performance of the dynamical downscaling at two different levels: first, within the own CMEMS service (with their regional products, as enhanced solutions with respect to the global one) and second in the coastal down-streaming service side (with very high-resolution models reaching coastal scales). This multi-model study case focused on Storm Gloria has allowed to identify some strengths and limitations of the systems currently in operations, and it can help outlining future model service upgrades aimed at better forecasting extreme coastal events.This study has been conducted using E.U. Copernicus Marine Service Information. Specifically, from its NRT forecast products for the global, Mediterranean basin and the IBI area. Likewise, HF radar and ocean in situ observations from the Puertos del Estado and the SOCIB observing networks and systems have been used. The authors acknowledge the MEDCLIC project (LCF/PR/PR14/11090002), funded by “La Caixa” Foundation, contributing to the development of the WMOP hydrodynamic model.Peer ReviewedPostprint (published version

Storm Gloria: sea state evolution based on in situ measurements and modeled data and its impact on extreme values

Storm Gloria, generated on January 17th, 2020 in the Eastern North Atlantic, crossed the Iberian Peninsula and impacted the Western Mediterranean during the following days. The event produced relevant damages on the coast and the infrastructures at the Catalan-Balearic Sea, due to extraordinary wind and wave fields, concomitant with anomalously intense rain and ocean currents. Puertos del Estado (the Spanish holding of harbors) has developed and operates a complex monitoring and forecasting system (PORTUS System), in collaboration with the Spanish Met Office (AEMET). The present work shows how Gloria was correctly forecasted by this system, alerts were properly issued (with special focus to the ports), and the buoys were able to monitor the sea state conditions during the event, measuring several new records of significant wave height and exceptional high mean wave periods. The paper describes, in detail, the dynamic evolution of the atmospheric conditions, and the sea state during the storm. It is by means of the study of both in situ and modeled PORTUS data, in combination with the AEMET weather forecast system results. The analysis also serves to place this storm in a historical context, showing the exceptional nature of the event, and to identify the specific reasons why its impact was particularly severe. The work also demonstrates the relevance of the PORTUS System to warn, in advance, the main Spanish Ports. It prevents accidents that could result in fatal casualties. To do so, the wave forecast warning performance is analyzed, making special focus on the skill score for the different horizons. Furthermore, it is demonstrated how a storm of this nature results in the need of changes on the extreme wave analysis for the area. It impacts all sorts of design activities at the coastline. The paper studies both how this storm fits into existing extreme analysis and how these should be modified in the light of this particular single event. This work is the first of a series of papers to be published on this issue. They analyze, in detail, other aspects of the event, including evolution of sea level and description of coastal damages

Regional marine climate scenarios in the NE Atlantic sector close to the Spanish shores

[EN] We present an overview of the changes expected during the 21st century in key marine parameters (sea surface temperature, sea surface salinity, sea level and waves) in the sector of the NE Atlantic Ocean close to the Spanish shores. Under the A1B scenario, open-sea surface temperatures would increase by 1°C to 1.5°C by 2050 as a consequence of global ocean warming. Near the continental margin, however, the global temperature rise would be counteracted by an enhancement of the seasonal upwelling. Sea surface salinity is likely to decrease in the future, mainly due to the advection of high-latitude fresher waters from ice melting. Mean sea level rise has been quantified as 15-20 cm by 2050, but two contributions not accounted for by our models must be added: the mass redistribution derived from changes in the large-scale circulation (which in the NE Atlantic may be as large as 15 cm in 2050 or 35 cm by 2100) and the increase in the ocean mass content due to the melting of continental ice (for which estimates are still uncertain). The meteorological tide shows very small changes, and therefore extreme sea levels would be higher in the 21st century, but mostly due to the increase in mean sea level, not to an increase in the storminess. The wave projections point towards slightly smaller significant wave heights, but the changes projected are of the same order as the natural variability.[ES]En este trabajo se presenta una visión de conjunto de los cambios esperados en el siglo XXI en los principales parámetros marinos (temperatura y salinidad superficiales, nivel del mar y oleaje) en el sector NE del Océano Atlántico más cercano a las costas españolas. Bajo el escenario A1B, se prevé que la temperatura superficial en mar abierto suba del orden de 1-1.5°C para el año 2050, como consecuencia del calentamiento global del océano. Cerca del margen continental, sin embargo, el aumento de la temperatura superficial podría ser contrarrestado por un aumento del afloramiento estacional. La salinidad superficial es probable que disminuya en el futuro, debido principalmente a la advección desde latitudes más altas de aguas provenientes de la fusión de hielos polares. El aumento del nivel del mar obtenido de los modelos se ha cuantificado en 15 a 20 cm para el año 2050, pero esa estima no incluye dos contribuciones adicionales que deben ser añadidas: la redistribución de masa derivada de los cambios en la circulación a gran escala (que en el Atlántico NE se ha estimado en unos 15 cm para 2050 i en 35 cm para 2100) y el aumento de masa debido a la fusión de hielos continentales (para el cual las estimas son todavía inciertas). La marea meteorológica muestra cambios muy pequeños, y por tanto el aumento de los niveles extremos del mar en el siglo XXI serán debidos principalmente al aumento del nivel medio, no a un aumento en la intensidad de las tormentas. Las proyecciones de oleaje apuntan a olas de altura significante ligeramente más pequeñas; de todos modos, los cambios proyectados son del mismo orden que la variabilidad natural.The computational work of this paper was carried out in the framework of two projects: VANIMEDAT-2 (CTM2009-10163-C02-01), funded by the Spanish Ministerio de Economía y Competitividad (MINECO) and the E-Plan of the Spanish Government; and ESCENARIOS, funded by the Agencia Estatal de Meteorología (AEMET). Some of the analysis and summary efforts were carried out in the framework of the subsequent project CLIMPACT (CGL2014-54246-C2-1-R), also funded by MINECO