• Energy Research

Abstract The advances in floating offshore wind energy are opening deep sea areas, like the coastal waters of Iberian Peninsula (IP), for the installation of wind farms. The integration of this new energy source in a semi-closed power system with an already high share of variable renewable energies would be facilitated if the potential contribution of offshore wind energy shows reduced variability and limited seasonal variations, as the power demand in IP shows two maxima in winter and summer. The aims of this study are the analysis of temporal variability and spatial complementarity of the potential installation sites, and the identification of an optimal combination of installation areas that minimizes the temporal variability of the aggregated offshore contribution. In order to better capture the marked mesoscale features of winds around the IP, wind data from a very high resolution reanalysis (COSMO-REA6) are used. The analysis considers allowed areas for installation, delimited by the maritime spatial planning. Northern coast areas are characterized by high capacity factors (CFs) and high seasonality, while the lower CFs at the western and southern coasts are compensated by a limited seasonality. Pairwise correlation between the potential areas shows outstanding results, with several negative correlation values within a synoptic scale region, in contrast to other mid-latitude regions like the North Sea or the Eastern USA coast. An optimal aggregation of areas includes at least one area at each of the four main Iberian coasts. A strong reduction of hourly variability is obtained through the resulting combinations, and the seasonality of the aggregated CF is clearly below the values for other offshore areas. Therefore, offshore wind energy can indeed offer an added value for the Iberian power system beyond the high resource amount, reducing the need for storage or backup plants.

AbstractThe European CORDEX (EURO-CORDEX) initiative is a large voluntary effort that seeks to advance regional climate and Earth system science in Europe. As part of the World Climate Research Programme (WCRP) - Coordinated Regional Downscaling Experiment (CORDEX), it shares the broader goals of providing a model evaluation and climate projection framework and improving communication with both the General Circulation Model (GCM) and climate data user communities. EURO-CORDEX oversees the design and coordination of ongoing ensembles of regional climate projections of unprecedented size and resolution (0.11° EUR-11 and 0.44° EUR-44 domains). Additionally, the inclusion of empirical-statistical downscaling allows investigation of much larger multi-model ensembles. These complementary approaches provide a foundation for scientific studies within the climate research community and others. The value of the EURO-CORDEX ensemble is shown via numerous peer-reviewed studies and its use in the development of climate services. Evaluations of the EUR-44 and EUR-11 ensembles also show the benefits of higher resolution. However, significant challenges remain. To further advance scientific understanding, two flagship pilot studies (FPS) were initiated. The first investigates local-regional phenomena at convection-permitting scales over central Europe and the Mediterranean in collaboration with the Med-CORDEX community. The second investigates the impacts of land cover changes on European climate across spatial and temporal scales. Over the coming years, the EURO-CORDEX community looks forward to closer collaboration with other communities, new advances, supporting international initiatives such as the IPCC reports, and continuing to provide the basis for research on regional climate impacts and adaptation in Europe.

AbstractUnderstanding space–time features of wind speed is of high interest in meteorology and several applied sciences. Accurate wind speed measurements in combination with reliable gridded products, such as reanalyses, are needed to address the main characteristics of the wind field. Hourly 10 m wind speed from the European Centre for Medium‐Range Weather Forecasts (ECMWF) latest reanalysis (ERA5) is compared with HadISD wind observations from 245 stations across Europe. Averaged ERA5 hourly data is able to reproduce the annual cycle of monthly wind speed in Europe. ERA5 presents slightly larger (shorter) monthly medians in winter (summer) than observations. ERA5 is compared against observations for each station using a frequency distribution‐based score (score, from 0 to 1). Most of the stations exhibit hourly scores ranging from 0.8 to 0.9, indicating that ERA5 is able to reproduce the wind speed spectrum range, from light to strong relative frequencies, for any location over Europe. Ranges of mean values, variability, distribution function parameters and high or low wind thresholds frequencies are shown for this ensemble of European stations, allowing for an overall description of wind features. Generally, there is no clear relationship between scores and the variables analysed. The correlation and scores between ERA5 and HadISD is even further increased at longer time frequencies (6–24 hourly), together with centred root‐mean‐square error (RMSE) and standard deviation decreases. Hourly wind data from ERA5 reanalysis is, despite some shortcomings, valuable information to perform further detailed studies with a regular spatial and time wind distribution, from the climatological or renewable energy perspectives, for example.

AbstractIn the context of the CORDEX project, an ensemble of regional climate simulations (RCMs) of high resolution on a 0.11° grid has been generated for Europe with the objective of improving the representation of regional to local‐scale atmospheric phenomena. However, such simulations are computationally expensive and do not always reveal added value. Here, a recently proposed metric (the distribution added value [DAV]) is used to determine the added value of all available EURO‐CORDEX high‐resolution simulations at 0.11° for daily mean wind speed compared to their respective coarser‐gridded 0.44° counterparts and their driving fields, hindcast and historical experiments. The analysis consists in comparing the degree of similarity between normalized wind probability density function (PDF) of simulations and observations. In addition, the use of a normalized PDF allows for a direct spatial comparison among the different regions and time periods. Results show that RCMs add value to their reanalysis or forcing global model, but the nature and magnitude of the improvement on the representation of wind speed may vary depending on the model, region and season. We found most RCMS at 0.11° to outperform models at the 0.44° resolution in terms of their quality in capturing the measured wind speed PDF. When looking at the upper tail of the wind speed PDF, the benefits of downscaling are generally larger. At the regional scale, added value is obtained for 0.11° with respect to 0.44° resolution for all subdomains studied, particularly over the Mediterranean, the Iberian Peninsula and the Alps. When analysing the added value dependence on altitude, runs at 0.11° models represent better the locations below 50 m and above 350 m of altitude, and the 0.44° increasingly under‐perform for higher altitudes. Overall, DAV are larger at 0.11° than at 0.44° resolution, due to a better performance of local‐scale feedbacks at high resolution.

Fil: Lopez de la Franca Arema, Noelia. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Oficina de Coordinacion Administrativa Ciudad Universitaria. Centro de Investigaciones del Mar y la Atmosfera. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Centro de Investigaciones del Mar y la Atmosfera; Argentina. Instituto Franco-Argentino para el Estudio del Clima y sus Impactos; Argentina

Cyclones with tropical characteristics, usually called medicanes, occasionally develop over the Mediterranean Sea.