High Frequency Radar (HFR) is a land-based remote sensing instrument offering a unique insight to coastal ocean variability, by providing synoptic, high frequency and high resolution data at the ocean atmosphere interface. HFRs have become invaluable tools in the field of operational oceanography for measuring surface currents, waves and winds, with direct applications in different sectors and an unprecedented potential for the integrated management of the coastal zone. In Europe, the number of HFR networks has been showing a significant growth over the past 10 years, with over 50 HFRs currently deployed and a number in the planning stage. There is also a growing literature concerning the use of this technology in research and operational oceanography. A big effort is made in Europe toward a coordinated development of coastal HFR technology and its products within the framework of different European and international initiatives. One recent initiative has been to make an up-to-date inventory of the existing HFR operational systems in Europe, describing the characteristics of the systems, their operational products and applications. This paper offers a comprehensive review on the present status of European HFR network, and discusses the next steps toward the integration of HFR platforms as operational components of the European Ocean Observing System, designed to align and integrate Europe's ocean observing capacity for a truly integrated end-to-end observing system for the European coasts.

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Tidal stream turbines provide a technically viable means of generating electricity from a sustainable resource; however, economic viability will require the deployment of multiple devices in array formations in a manner analogous to wind farms. This research investigates the effect of the configuration of a tidal turbine array on the hydroenvironmental impacts of the array such as changes in tidal flows and water surface levels.The Shannon Estuary, a highly energetic estuary on the west coast of Ireland with significant potential for tidal current energy extraction, was simulated using a depth integrated 2D hydroenvironmental model, namely DIVAST. The numerical model was modified to incorporate the effects of energy extraction on the tidal regime and a multiple device array was simulated. Three different array configurations were examined with turbine spacings of 0.5, 2 and 5 rotor diameters. The model results demonstrate that energy extraction has an attenuation effect on the currents within the array while flow is accelerated around the array. Water surface elevations are also affected with a reduction in tidal range upstream of the array. The magnitude and extent of the observed impacts are greater for the smallest turbine spacing but were still significant for the larger spacings.

An assessment of the complex evolution of climate change signals in the Irish Sea over the 21 st century is presented in this paper. Potential impacts of climate change on the local hydrography are explored and interrelationships between fundamental oceanographic shelf sea phenomena investigated. A regional ECOMSED ocean model is used to downscale a 120-year period of the SRES A1B scenario experiment from a global ocean model. A detailed regional analysis shows that local climate changes may be significantly different from the expected global changes.This research suggests that in the future the Irish Sea will be warmer with sea surface temperature increase of around 1.9˚C. Maxima and minima annual temperatures will occur around 2 weeks later each year relative to the present climate. Geographically, shallow waters along the coastline and in the eastern Irish Sea will exhibit strongest warming due to increased heat uptake during summer and autumn and reduced heat loss in spring and winter. Warming in the deep channel in the western Irish Sea will be generally weaker with seasonal variability subdued due to a large heat storage capacity. The warming will be largely stored in the surface layer of the water column leading to strengthening of stratification and a considerable decrease in the thickness of the mixed layer. The western Irish Sea gyre will become stronger and result in substantial reinforcement (>30%) of southward currents along the east coast of Ireland. Net northward flow in future climate will be maintained at the 2 current annual rate. Steric sea level is projected to rise by 0.31m during the 21 st century, leading to an overall projected sea level rise of approximately of 0.47m.Future changes to oceanographic parameters, flushing times and hydrodynamics of the Irish Sea are likely to alter the habitat and distribution of marine species; the finding of this research are therefore of great interest to ecologists and the fishery industry.

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