Coastal warming was analyzed by means of satellite‐derived sea surface temperature (SST) along the continental part of the Atlantic Arc extending from 37°N to 48°N for the period 1985–2005. ...Interannual SST variability calculated from anomalies shows an inhomogeneous warming trend in coastal SST (ΔSST). Coastal warming trend ranges from 3.5°C 100 a−1 at latitudes close to 48°N to 1.2°C 100 a−1 at latitudes close to 37°N. This warming is observed to reflect oceanic ΔSST which increases northward in the Atlantic area. In addition, a westward increase was also observed across the North Atlantic. Coastal warming is not constant all year long. It only occurs during spring and summer in the entire area under scope, following a trend similar to the annual one. The mean spring ΔSST values are 5.1°C 100 a−1 in the French coast, 4.4°C 100 a−1 in the Cantabrian coast, and 3.8°C 100 a−1 in the western Iberian Peninsula coast. Similar values (5.0°C 100 a−1, 3.7°C 100 a−1, and 2.7°C 100 a−1) are observed in summer.
The spatial distribution of the muddy fine sand community from the Bay of Veys (western English Channel) were investigated during spring and autumn 1997. A grid of 55 and 54 sites was sampled in ...March and October, respectively, using two replicates per site of a Hamon grab (0.25 m
2) for macrofauna collection and an additional one for sediment analysis. A total of 172 species were sampled with a dominance of polychaetes, followed by crustaceans and bivalves. The species richness and abundance show low temporal changes despite higher values in October than in March. In March, the mean abundance was 165 ind. 0.5 m
−2; in October, the mean abundance was 212 ind. 0.5 m
−2. Four assemblages from the
Abra alba–
Pectinaria koreni community were identified corresponding to a bathymetric and sedimentary gradient from muddy fine sands with high levels of fine particles in shallow water to fine sands in deeper water. The discussion focuses on factors prevailing on the spatial structure of sandy communities in the English Channel.
This paper presents Iber+, a new parallel code based on the numerical model Iber for two-dimensional (2D) flood inundation modelling. The new implementation, which is coded in C++ and takes advantage ...of the parallelization functionalities both on CPUs (central processing units) and GPUs (graphics processing units), was validated using different benchmark cases and compared, in terms of numerical output and computational efficiency, with other well-known hydraulic software packages. Depending on the complexity of the specific test case, the new parallel implementation can achieve speedups up to two orders of magnitude when compared with the standard version. The speedup is especially remarkable for the GPU parallelization that uses Nvidia CUDA (compute unified device architecture). The efficiency is as good as the one provided by some of the most popular hydraulic models. We also present the application of Iber+ to model an extreme flash flood that took place in the Spanish Pyrenees in October 2012. The new implementation was used to simulate 24 h of real time in roughly eight minutes of computing time, while the standard version needed more than 15 h. This huge improvement in computational efficiency opens up the possibility of using the code for real-time forecasting of flood events in early-warning systems, in order to help decision making under hazardous events that need a fast intervention to deploy countermeasures.
We explored the possible effects of the North Atlantic Oscillation (NAO) and Arctic Oscillation (AO) on interannual sea surface temperature (SST) variations in the Alborán Sea, both separately and ...combined. The probability of observing mean annual SST values higher than average was related to NAO and AO values of the previous year. The effect of NAO on SST was negative, while that of AO was positive. The pure effects of NAO and AO on SST are obscuring each other, due to the positive correlation between them. When decomposing SST, NAO and AO in seasonal values, we found that variation in mean annual SST and mean winter SST was significantly related to the mean autumn NAO of the previous year, while mean summer SST was related to mean autumn AO of the previous year. The one year delay in the effect of the NAO and AO on the SST could be partially related to the amount of accumulated snow, as we found a significant correlation between the total snow in the North Alborán watershed for a year with the annual average SST of the subsequent year. A positive AO implies a colder atmosphere in the Polar Regions, which could favour occasional cold waves over the Iberian Peninsula which, when coupled with precipitations favoured by a negative NAO, may result in snow precipitation. This snow may be accumulated in the high peaks and melt down in spring-summer of the following year, which consequently increases the runoff of freshwater to the sea, which in turn causes a diminution of sea surface salinity and density, and blocks the local upwelling of colder water, resulting in a higher SST.
•Analysis of the combined effect of computational mesh and DTM resolutions.•Study conducted in 4 basins and a total of 7 precipitation events.•In each basin, 3 DTM resolutions and 3 mesh resolutions ...were considered.•Rainfall events were modelled with a fully distributed hydrodynamic 2D-SWE model.
Modelling hydrological processes with fully distributed models based on the shallow water equations implies a high computational cost, which often limits the resolution of the computational mesh. Therefore, in practice, modellers need to find a compromise between spatial resolution, numerical accuracy and computational cost. Moreover, this balance is probably related to the accuracy and resolution of the underlying Digital Terrain Model (DTM). In this work, it is studied the effect of the DTM resolution and the size of the computational mesh on the results and on the runtime of a hydrological model based on the 2D shallow water equations. Seven rainfall events in four different basins have been modelled using 3 DTMs and 3 different mesh resolutions. The results obtained highlight the relevance of the vertical accuracy versus the horizontal resolution of the DTMs. Furthermore, it has been observed that mesh resolutions greater than 25 m, together with LiDAR-based DTMs with horizontal resolution greater than 25 m, provide comparable outflow hydrographs.
Numerical models are useful tools to analyze water quality by computing the concentration of physical, chemical and biological parameters. The present work introduces a two-dimensional depth-averaged ...model that computes the most relevant and frequent parameters used to evaluate water quality. High performance computing (HPC) techniques based on graphic processing unit (GPU) parallelization have been applied to improve the efficiency of the package, providing speed-ups of two orders of magnitude in a standard PC. Several test cases were analyzed to show the capabilities and efficiency of the model to evaluate the environmental status of rivers and non-stratified estuaries. IberWQ will be freely available through the package Iber.
We explored the possible effects of the North Atlantic Oscillation (NAO) and Arctic Oscillation (AO) on interannual sea surface temperature (SST) variations in the Alboran Sea, both separately and ...combined. The probability of observing mean annual SST values higher than average was related to NAO and AO values of the previous year. The effect of NAO on SST was negative, while that of AO was positive. The pure effects of NAO and AO on SST are obscuring each other, due to the positive correlation between them. When decomposing SST, NAO and AO in seasonal values, we found that variation in mean annual SST and mean winter SST was significantly related to the mean autumn NAO of the previous year, while mean summer SST was related to mean autumn AO of the previous year. The one year delay in the effect of the NAO and AO on the SST could be partially related to the amount of accumulated snow, as we found a significant correlation between the total snow in the North Alboran watershed for a year with the annual average SST of the subsequent year. A positive AO implies a colder atmosphere in the Polar Regions, which could favour occasional cold waves over the Iberian Peninsula which, when coupled with precipitations favoured by a negative NAO, may result in snow precipitation. This snow may be accumulated in the high peaks and melt down in spring-summer of the following year, which consequently increases the runoff of freshwater to the sea, which in turn causes a diminution of sea surface salinity and density, and blocks the local upwelling of colder water, resulting in a higher SST.
In the aim of promoting the responsible and sustainable management of the European fishing activity, the European Commission took a number of actions oriented to the implementation of "no-discard" ...and "zero-waste" policies to be followed by the European fishing fleets in the near future. In particular, actions were directed to the development of policies to reduce unwanted by-catches and eliminate discards in European fisheries, as well as to make the best possible use of the captured resources avoiding its waste. In this sustainability framework, the FAROS Projects (co-funded under the LIFE+ Environmental Program of the European Union) aims at developing and implementing an efficient and integral discards and by-catch management network based on a global and real-time information system both on board and in land. This network implies all actors present in the fishing sector (fleets, ports, auctions, industries, etc.) and takes advantage of the existing synergies between them in order to attain the minimization of discards/by-catch as well as their optimal valorization to recover and to produce valuable chemicals of interest in the food and pharmaceutical industry.
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