Wave climate for inland vessels between Zeebrugge and the mouth of the Western Scheldt: estimation by the Belgian coast model in SWAN

The Masterplan 'Vlaamse Baaien' outlines the need to develop an integrated vision for the Belgian coast. One of the Masterplan’s goals is to achieve a win-win situation between coastal protection and the maintenance and improvement of the maritime access to the port of Zeebrugge.The hinterland connection of the port of Zeebrugge by means of inland vessels is a major issue. Therefore, a specific type of inland vessels is conditionally allowed to make use of the 16 nautical miles long sea trajectory between Zeebrugge and the mouth of the Western Scheldt estuary to connect the port with the inland waterway network.Detailed information about the wave climate in the area between the eastern dam of the port of Zeebrugge, Pas van het Zand, Scheur-Oost/Wielingen, Vlissingen, Breskens and the coastline is essential to maximize the efficiency of the sea-river traffic in the present situation, and to decrease the requirements of inland vessels for safe navigation on a coastal route between the port of Zeebrugge and the mouth of the Western Scheldt.The existing project focuses on the model set-up and calculation of the detailed wave climate between Zeebrugge and the mouth of the Western Scheldt estuary in the present situation and also a future configuration for wind, wave and water level conditions throughout the year 2013 by means of the validated numerical model. The result of the simulation are delivered to the client for the further analysis (e.g. shading effects of new islands scenarios for the ship navigation). Research results can be used for the further analysis of the navigation of all vessels which are making use of the present route and future alternative routes. Besides, it can serve as a basis to evaluate the impact of measures on the response of inland vessels

Gas condensation in brightest group galaxies unveiled with MUSE: Morphology and kinematics of the ionized gas

The origin of the cold gas in central galaxies in groups is still a matter of debate. We present Multi-Unit Spectroscopic Explorer (MUSE) observations of 18 optically selected local (z ≤ 0:017) brightest group galaxies (BGGs) to study the kinematics and distribution of the optical emission-line gas. MUSE observations reveal a distribution of gas morphologies including ten complex networks of filaments extending up to ∼10 kpc to two compact (<3 kpc) and five extended (>5 kpc) disk-dominated structures. Some rotating disks show rings and elongated structures arising from the central disk. The kinematics of the stellar component is mainly rotationdominated, which is very different from the disturbed kinematics and distribution found in the filamentary sources. The ionized gas is kinematically decoupled from the stellar component for most systems, suggesting an external origin for the gas. We also find that the Hα luminosity correlates with the cold molecular gas mass. By exploring the thermodynamical properties of the X-ray atmospheres, we find that the filamentary structures and compact disks are found in systems with small central entropy values, K, and tcool=teddy ratios. This suggests that, similar to brightest cluster galaxies (BCGs) in cool core clusters, the ionized filaments and the cold gas associated to them are likely formed from hot halo gas condensations via thermal instabilities, which is consistent with the chaotic cold accretion simulations (as shown via the C ratio, Tat, and k plot). We note that the presence of gaseous rotating disks is more frequent than in BCGs. An explanation for the origin of the gas in those objects is a contribution to gas fueling by wet mergers or group satellites, as qualitatively hinted at by some sources of the present sample. Nonetheless, we discuss the possibility that some extended disks could also be a transition stage in an evolutionary sequence including filaments, extended disks, and compact disks, as described by hot gas condensation models of cooling flows

Benchmarking homogenization algorithms for monthly data

The COST (European Cooperation in Science and Technology) Action ES0601: Advances in homogenization methods of climate series: an integrated approach (HOME) has executed a blind intercomparison and validation study for monthly homogenization algorithms. Time series of monthly temperature and precipitation were evaluated because of their importance for climate studies. The algorithms were validated against a realistic benchmark dataset. Participants provided 25 separate homogenized contributions as part of the blind study as well as 22 additional solutions submitted after the details of the imposed inhomogeneities were revealed. These homogenized datasets were assessed by a number of performance metrics including i) the centered root mean square error relative to the true homogeneous values at various averaging scales, ii) the error in linear trend estimates and iii) traditional contingency skill scores. The metrics were computed both using the individual station series as well as the network average regional series. The performance of the contributions depends significantly on the error metric considered. Although relative homogenization algorithms typically improve the homogeneity of temperature data, only the best ones improve precipitation data. Moreover, state-of-the-art relative homogenization algorithms developed to work with an inhomogeneous reference are shown to perform best. The study showed that currently automatic algorithms can perform as well as manual ones