West Coast Of Ireland Research Articles

Wave energy resource variation off the west coast of Ireland and its impact on realistic wave energy converters’ power absorption

Wave energy converters are specifically designed to extract the maximum energy from a given location. To that end, wave data statistics based on past measures at the given location are commonly used, neglecting any possible future wave trend. This paper studies the variations of the wave energy resource off the west coast of Ireland over the 20th century via the atmospheric reanalyses created by the European Centre for Medium-Range Weather Forecasts. In particular, the European Re-Analysis ERA20 is calibrated via quantile-matching against the new European Re-Analysis ERA-Interim for the period 1979–2010. In addition, the calibrated ERA20 reanalysis is validated against buoy measurements in the area of interest. Results show a significant increase of the wave energy resource along the last century (an increase of over 40%), for which the largest increase is observed within the last 20 years (an increase of 18% between 1980 and 2000). The paper shows that these variations considerably affect the power absorption of realistic devices, showing a power surplus of up to 15% within the lifespan of a wave energy converter. Finally, an increase of extreme events over the last century is also observed, highlighting its impact on power production due to the need of wave energy converters to switch into survival mode during extreme events.

Seasonal Variation Characteristics Of Winds At The West Coast Of Ireland

Coastal areas have a large content of renewable energies such as wind energy, tidal energy and wave energy. With continuous development of wind power generation, wind energy research at home and abroad is increasing. In this research, wind data over one year were obtained from ECMWF. In order to study wind variation characteristics, wind dataset was divided into four seasonal categories. Analysis of seasonal variation characteristics of winds at the west coast of Ireland provides useful information for wind energy development and wind energy assessment.

The Effect of Wind Forcing on Modeling Coastal Circulation at a Marine Renewable Test Site

The hydrodynamic circulation in estuaries is primarily driven by tides, river inflows and surface winds. While tidal and river data can be quite easily obtained for input to hydrodynamic models, sourcing accurate surface wind data is problematic. Inaccurate wind data can lead to inaccuracies in the surface currents computed by three-dimensional hydrodynamic models. In this research, a high-resolution wind model was coupled with a three-dimensional hydrodynamic model of Galway Bay, a semi-enclosed estuary on the west coast of Ireland, to investigate the effect of wind forcing on model accuracy. Two wind-forcing conditions were investigated: (1) using wind data measured onshore on the NUI Galway campus (NUIG) and (2) using offshore wind data provided by a high resolution wind model (HR). A scenario with no wind forcing (NW) was also assessed. The onshore wind data varied with time but the speed and direction were applied across the full model domain. The modeled offshore wind fields varied with both time and space. The effect of wind forcing on modeled hydrodynamics was assessed via comparison of modeled surface currents with surface current measurements obtained from a High-Frequency (HF) radar Coastal Ocean Dynamics Applications Radar (CODAR) observation system. Results indicated that winds were most significant in simulating the north-south surface velocity component. The model using high resolution temporally- and spatially-varying wind data achieved better agreement with the CODAR surface currents than the model using the onshore wind measurements and the model without any wind forcing.

Real-Time Passive Control of Wave Energy Converters Using the Hilbert-Huang Transform

Passive loading is a suboptimal method of control for wave energy converters (WECs) that usually consists of tuning the power take-off (PTO) damping of the WEC to either the energy or the peak frequency of the local wave spectrum. Such approach results in a good solution for waves characterized by one-peak narrowband spectra. Nonetheless, real ocean waves are non-stationary by nature, and sea wave profiles with different spectral distribution occur in a specific location over time. Thus, the average energy absorption of passively controlled WECs tends to be low. In this paper, we propose a real-time passive control (PC) based on the Hilbert-Huang transform (HHT), where the PTO damping is time-varying and tuned to the instantaneous frequency of the wave excitation force. The instantaneous frequency is calculated by using the HHT, an analysis method for nonlinear and non-stationary signals that relies on the local characteristic time-scale of the signal. A performance comparison (in terms of energy absorption) of the proposed solution with the passive loading method is presented for a heaving system, in a variety of wave spectra. It is shown that a performance improvement of up to 21%, or 65%, is obtained for the proposed PC scheme, when it is compared to passive loading tuned to the energy, or the peak frequency of the spectrum, respectively. Real ocean waves off the west coast of Ireland are adopted in the simulations.

Machine learning approach for optimal determination of wave parameter relationships

Wave parameter relationships have long been determined using methods that give non-standard and often inaccurate results. With increased commercial activity in the marine sector, the importance of accurate wave parameter relationship determination has become increasingly apparent. The outputs of many numerical models and buoy datasets do not include all requisite wave parameters, and a typical approach is to use a constant conversion factor or relationship based on defined spectra such as the Bretschneider or the joint North Sea wave observation project (JONSWAP) spectrum to determine these parameters. Given that relationships between wave parameters vary significantly over both hourly and seasonal and annual timescales, the currently employed methods are lacking, as subtleties are missed by the simpler approach. This paper addresses the determination of wave parameter relationships using a machine learning (ML)-based model, identifying and selecting the optimal method for the conversion of wave parameters (T e, T 01) in coastal Irish Waters. This approach is then validated at two sites on the West coast of Ireland. The aim is to highlight the utility of ML in approximating the relationship between wave parameters; using both buoy and modelled data, and mapping the predicted outcomes for a wave energy converter based on a variety of ML and measure correlate predict approaches.

At a Crossroads: Investigating Automobility and Its Implications for Local Urban Transport Policy Design

More people than ever before are living in urban settlements, increasing competition for living space, employment, food, water, and energy. Urbanisation poses many challenges, most notably meeting the basic health and well-being needs of inhabitants. One of the key challenges faced is the increase in transport-related energy consumption and its negative economic, environmental, and social consequences. Cities and towns are complex spatial structures supported by transport systems, and automobility dominates many urban planning decisions. Such approaches to transportation and land use patterns favour and promote car use, providing inadequate alternatives or more sustainable modes of transport such as public transport, cycling, and walking. However, automobility is now deemed unsustainable, and moves toward more sustainable modes of transport are both necessary and essential to improving the quality of life for all citizens. This study seeks to determine levels of automobility thinking and attitudes to transportation in Galway, a small city on the west coast of Ireland, and provides an innovative, quantitative measure of reliance on this single mode of transport. Results indicate people who live in the city are not as car dependent as its rural hinterlands, although this is seldom reflected in local authority and regional transport approaches and decision-making.

Living with Ghosts: Re-inventing the Easter Rising in The Dreaming of the Bones and Calvary

This article looks at two plays written after Easter, 1916 ; I argue that these plays revise the earlier poem's claim that all [is] changed and dramatise instead the persistence of past wounds and blemishes in the post-revolutionary present. In The Dreaming of the Bones, a young rebel who has just been fighting in the Rising is hiding from the police on the West coast of Ireland, where he encounters the ghosts of Diarmuid and Dervorgilla, whose betrayal, he says, brought the Norman in and thus started the colonisation of Ireland. Calvary (written in 1920, but never performed in Yeats's lifetime) is an unorthodox Passion play, dramatising Christ's dreaming back of his own Passion on Good Friday, as he is confronted by the ghosts of Lazarus, Judas and the three Roman soldiers who nailed him to the Cross. Although it is ostensibly unrelated to the Easter Rising, it reads as an ironic yet compassionate comment on the Passion play that the Easter Rising, at one level, replayed.

Piscirickettsia salmonis infection in cultured lumpfish (Cyclopterus lumpus L.).

A Piscirickettsia salmonis infection was diagnosed in lumpfish (Cyclopterus lumpus L.) juveniles held in a marine research facility on the west coast of Ireland. The main clinical signs and pathology included marked ascites, severe multifocal liver necrosis and severe diffuse inflammation and necrosis of the exocrine pancreas and peri-pancreatic adipose tissue. Numerous Piscirickettsia-like organisms were observed by histopathology in the affected organs, and the bacterial species was characterized by molecular analysis. Sequencing of the partial 16S rDNA gene and internal transcribed spacer region showed the lumpfish sequences to be closely related to previously identified Atlantic salmon (Salmo salar L.) sequences from Ireland. To the authors' knowledge, this is the first detection of P.salmonis in lumpfish worldwide. The infection is considered potentially significant in terms of lumpfish health and biosecurity.

Vitamin D Deficiency and Insufficiency Prevalence in the West of Ireland - A Retrospective Study.

Vitamin D plays an important role in calcium homeostasis and is essential for normal bone growth and remodeling. Previous studies of acutely ill and institutionalized older women in Galway revealed that vitamin D insufficiency is extremely common. We aimed to evaluate age and gender-related rates of vitamin D insufficiency and deficiency in adult patients attending their General Practitioners in the same region. A retrospective cohort study. General practices in Galway, a city located on the west coast of Ireland, latitude 53.17 North. A total of 15,708 consecutive blood samples from adults attending their General Practitioners between January 2013 and December 2014 were sent to the Clinical Biochemistry Laboratory in the University Hospital Galway for vitamin D level testing. 73% were from women. Data were collected and grouped according to age, sex and season. Vitamin D levels (25OHD) were categorised into deficiency (<25nmol/L), insufficiency (25-50nmol/L) and sufficiency ( >50nmol/L). Median and interquartile range were reported as vitamin D levels were not normally distributed. Descriptive statistics were performed using STATA/MP 13.1 for Mac. While vitamin D levels were sufficient in 56.4% (n=8,496), they were insufficient in 32.4% (n=4,891) and deficient in 11.2% (n=1,691). Of the deficient group, 19%( 325) had levels <15nmol/L consistent with profound deficiency. Men were more likely than women to be deficient (12% (n=489) vs. 10.9% (n=1,202)) and insufficient (38.0% (n=1,550) vs. 30.4% (n=3,341)) (p<0.01). Highest rates of deficiency were seen in those 81-97 years (19.4% (n=136)) and 18-40 years (13.8% (n=543)), the former group showing less seasonal variation. Overall prevalence of insufficiency is similar to those in national and European studies published recently. However, there is a high possibility that those most vulnerable to vitamin D deficiency were underrepresented in this cohort, when results from previous studies in the same region are considered. Further prospective studies are needed to guide treatment with supplementation of vitamin D for appropriate subgroups.

NAO and extreme ocean states in the Northeast Atlantic Ocean

Abstract. Large scale atmospheric oscillations are known to have an influence on waves in the North Atlantic. In quantifying how the wave and wind climate of this region may change towards the end of the century due to climate change, it is useful to investigate the influence of large scale oscillations using indices such as the North Atlantic Oscillation (NAO: fluctuations in the difference between the Icelandic low pressure system and the Azore high pressure system). In this study a statistical analysis of the station-based NAO index was carried out using an ensemble of EC-Earth global climate simulations, where EC-Earth is a European-developed atmosphere ocean sea-ice coupled climate model. The NAO index was compared to observations and to projected changes in the index by the end of the century under the RCP4.5 and RCP8.5 forcing scenarios. In addition, an ensemble of EC-Earth driven WAVEWATCH III wave model projections over the North Atlantic was analysed to determine the correlations between the NAO and significant wave height (Hs) and the NAO and extreme ocean states. For the most part, no statistically significant differences were found between the distributions of observed and modelled station-based NAO or in projected distributions of the NAO. Means and extremes of Hs are projected to decrease on average by the end of this century. The 95th percentile of Hs is strongly positively correlated to the NAO. Projections of Hs extremes are location dependent and in fact, under the influence of positive NAO the 20-year return levels of Hs were found to be amplified in some regions. However, it is important to note that the projected decreases in the 95th percentile of Hs off the west coast of Ireland are not statistically significant in one of the RCP4.5 and one of the RCP8.5 simulations (me41, me83) which indicates that there is still uncertainty in the projections of higher percentiles.

Saudade in the City: Kevin Barry’s City of Bohane

Set 40 years in the future, the once great city of Bohane on the west coast of Ireland is in terminal decline, with vice and tribal splits rife. Logan Hartnett, godfather of the Hartnett Fancy gang has been in charge but his nemesis has arrived back in town, his henchmen are becoming ambitious, his wife wants him to give it all up and go straight and, he has his mother to contend with. ISBN: 9780099549154

Development of a nested local scale wave model for a 1/4 scale wave energy test site using SWAN

ABSTRACTA numerical wave model is developed to simulate wave conditions at the 1/4 scale wave energy test site in Galway Bay on the west coast of Ireland. The Simulating Waves Nearshore gridded wave model (version 41.01) is used and a nesting methodology has been implemented to downscale from oceanic scale to a local scale. The nesting methodology does not require the development of a global wave model and instead uses freely available data from existing global models to provide boundary conditions to the regional coarse model. The nesting methodology can be relatively easily implemented for different parts of the world's oceans depending on available data and study requirements. In the present application, the regional coarse domain covers a large area of the north-eastern Atlantic Ocean at a resolution of 0.05° and the local Galway Bay domain is resolved at 0.0027° (approximately 300 m). Boundary conditions for the local high-resolution model are supplied from the coarse model. A detailed description of model input preparation is presented. The models were calibrated against wave buoy stations within the north-eastern Atlantic Ocean for the period of November 2013 and sensitivity tests were conducted on domain size, wave growth formulations and boundary specification. Model validation was conducted for a 3-year hindcast from 2011 to 2013 and it is shown that the developed wave model performs satisfactorily for this longer period and is therefore suitable for use as a forecast model.

The Migration Link between Cois Fharraige and Portland, Maine, 1880s to 1920s

From the 1880s onwards, the west coast of Ireland — particularly the Congested Districts — formed a major source area of emigration to North America. This paper focuses on part of that outflow from Cois Fharraige. west of Galway city, which ended in Portland, Maine. A distinctive pattern of immigration characterised these Irish-speaking migrants in this relatively small east coast port, with occupational specialisation in longshore work for men and domestic service for women. An analysis of the migration link between these two coastal locations provides a useful insight into aspects of the diaspora of Irish-speakers.

Six years of surface remote sensing of stratiform warm clouds in marine and continental air over Mace Head, Ireland

AbstractA total of 118 stratiform water clouds were observed by ground‐based remote sensing instruments at the Mace Head Atmospheric Research Station on the west coast of Ireland from 2009 to 2015. Microphysical and optical characteristics of these clouds were studied as well as the impact of aerosols on these properties. Microphysical and optical cloud properties were derived using the algorithm SYRSOC (SYnergistic Remote Sensing Of Clouds). Ground‐based in situ measurements of aerosol concentrations and the transport path of air masses at cloud level were investigated as well. The cloud properties were studied in dependence of the prevailing air mass at cloud level and season. We found higher cloud droplet number concentrations (CDNC) and smaller effective radii (reff) with greater pollution. Median CDNC ranged from 60 cm−3 in marine air masses to 160 cm−3 in continental air. Median reff ranged from 8 μm in polluted conditions to 10 μm in marine air. Effective droplet size distributions were broader in marine than in continental cases. Cloud optical thickness (COT) and albedo were lower in cleaner air masses and higher in more polluted conditions, with medians ranging from 2.1 to 4.9 and 0.22 to 0.39, respectively. However, calculation of COT and albedo was strongly affected by liquid water path (LWP) and departure from adiabatic conditions. A comparison of SYRSOC results with MODIS (Moderate‐Resolution Imaging Spectroradiometer) observations showed large differences for LWP and COT but good agreement for reff with a linear fit with slope near 1 and offset of −1 μm.

Spatial Bayesian hierarchical modelling of extreme sea states

A Bayesian hierarchical framework is used to model extreme sea states, incorporating a latent spatial process to more effectively capture the spatial variation of the extremes. The model is applied to a 34-year hindcast of significant wave height off the west coast of Ireland. The generalised Pareto distribution is fitted to declustered peaks over a threshold given by the 99.8th percentile of the data. Return levels of significant wave height are computed and compared against those from a model based on the commonly-used maximum likelihood inference method. The Bayesian spatial model produces smoother maps of return levels. Furthermore, this approach greatly reduces the uncertainty in the estimates, thus providing information on extremes which is more useful for practical applications.

First record of Tetramicra brevifilum in lumpfish (Cyclopterus lumpus, L.).

A microsporidian species with 98.3-98.4% nucleotide identity to Tetramicra brevifilum (Journal of Fish Diseases, 3, 1980, 495) was diagnosed in lumpfish (Cyclopterus lumpus, L.) broodstock held at a breeding and rearing facility in western Ireland. The fish were wild-caught from the west coast of Ireland, and the first case was diagnosed one year after capture. Clinical signs included severe bloating, lethargy, exophthalmos, anorexia, white patches on the cornea and externally visible parasitic cysts on skin and fins. Necropsy revealed severe ascites, white nodules and vacuoles in all the internal organs and partial liquefaction of the skeletal muscle. On histological examination, microsporidian xenomas were observed in all internal organs, the skin, skeletal muscle, gills and the eyes. The microsporidian species was identified by molecular analysis and transmission electron microscopy. This is the first record of T. brevifilum infecting lumpfish, and the disease is considered to be of potential significance to the rising aquaculture industry of this species.

Development of a high resolution wave climate modelling methodology for offshore, nearshore and onshore locations of interest

The aim of this investigation was to develop a methodology to characterise the wave climate for offshore, nearshore and onshore locations of interest. The proposed methodology was applied to a domain located off the west coast of Ireland, adjacent to Loop Head, Co. Clare, and this was an area of interest for ocean energy development. A 3rd generation spectral wave model for the domain was developed, calibrated and validated using DHI’s MIKE 21 spectral wave modelling software along with sea state, met-ocean and bathymetric data obtained from a wide range of sources.The model yielded information on a range of indices including annual mean wave power, exploitable wave power, maximum wave height, percentage occurrence of a range of sea states and wave directionality at off-shore, near-shore, and on-shore locations.The models predictions were compared with local wave measurements for calibration and validation purposes obtained from a non-directional Datawell Waverider wave measurement buoy. The wave climate model predicted significant wave height and energy period at this location exhibiting a scatter index of less than 0.25 and a correlation coefficient greater than 0.85. The inclusion of a high resolution bathymetry dataset in the on-shore and coastal regions of the domain was the main driver in achieving this level of agreement between the data.The spectral wave model developed in this research programme will be useful for future wave energy research. Results from this model indicate that the domain off County Clare possesses an exploitable resource with promising levels of energy for potential wave energy projects. They also show that the near-shore and on-shore environment in this domain maintains good levels of power with relative filtering of extreme waves.

Seaweed Alaria esculenta as a biomonitor species of metal contamination in Aughinish Bay (Ireland)

The concentrations of ten metals (As, Cd, Cu, Fe, Hg, K, Na, Pb, Sn and Zn) were monitored in coastal seawater and biomass of the seaweed Alaria esculenta from Aughinish Bay on the West coast of Ireland during March–June 2014 in order to study their temporal variations and assimilation efficiencies and to assess the ecological quality of these ecosystems. Seawater and A. esculenta showed significant temporal variations in their metal concentrations during March–June 2014 and A. esculenta accumulated more efficiently Fe and Zn, but showed low sensitivity to Na and K. On the other hand, A. esculenta showed no active detoxication mechanisms for Cd and Pb, but no saturation point was observed during this work to any metal. Considering metal concentrations bioaccumulated by A. esculenta, the Irish coast of Aughinish Bay was always ecologically classified as “Class I – Unpolluted” during March–June 2014. The significant correlations between seawater and A. esculenta obtained to all metals proved that this seaweed species: (i) is a suitable biomonitor of metal contamination in Irish coasts; (ii) it can be included in the European Environmental Specimen Banks and (iii) it can be used in European Real-Time Environmental Monitoring Networks.

Comparative Genomic Analysis Reveals a Diverse Repertoire of Genes Involved in Prokaryote-Eukaryote Interactions within the Pseudovibrio Genus.

Strains of the Pseudovibrio genus have been detected worldwide, mainly as part of bacterial communities associated with marine invertebrates, particularly sponges. This recurrent association has been considered as an indication of a symbiotic relationship between these microbes and their host. Until recently, the availability of only two genomes, belonging to closely related strains, has limited the knowledge on the genomic and physiological features of the genus to a single phylogenetic lineage. Here we present 10 newly sequenced genomes of Pseudovibrio strains isolated from marine sponges from the west coast of Ireland, and including the other two publicly available genomes we performed an extensive comparative genomic analysis. Homogeneity was apparent in terms of both the orthologous genes and the metabolic features shared amongst the 12 strains. At the genomic level, a key physiological difference observed amongst the isolates was the presence only in strain P. axinellae AD2 of genes encoding proteins involved in assimilatory nitrate reduction, which was then proved experimentally. We then focused on studying those systems known to be involved in the interactions with eukaryotic and prokaryotic cells. This analysis revealed that the genus harbors a large diversity of toxin-like proteins, secretion systems and their potential effectors. Their distribution in the genus was not always consistent with the phylogenetic relationship of the strains. Finally, our analyses identified new genomic islands encoding potential toxin-immunity systems, previously unknown in the genus. Our analyses shed new light on the Pseudovibrio genus, indicating a large diversity of both metabolic features and systems for interacting with the host. The diversity in both distribution and abundance of these systems amongst the strains underlines how metabolically and phylogenetically similar bacteria may use different strategies to interact with the host and find a niche within its microbiota. Our data suggest the presence of a sponge-specific lineage of Pseudovibrio. The reduction in genome size and the loss of some systems potentially used to successfully enter the host, leads to the hypothesis that P. axinellae strain AD2 may be a lineage that presents an ancient association with the host and that may be vertically transmitted to the progeny.

The Use of Deep Water Berths and the Effect of Noise on Bottlenose Dolphins in the Shannon Estuary cSAC.

The Shannon Estuary on the west coast of Ireland is one of Europe's premier deepwater berths catering for ships up to 200,000 deadweight tonnage. It is also Ireland's only designated candidate special area of conservation for bottlenose dolphins under the EU Habitats Directive. Long-term static acoustic monitoring was carried out at a number of intensive shipping sites. In 2012, noise monitoring took place over a 6-month period (at 1 site) as part of Ireland's requirements under the Marine Strategy Framework Directive (MSFD). This is the first assessment of the potential effect of vessel traffic on the behavior of this discrete dolphin population.