35 research outputs found
Gender-based differences in learner English : A syntax study of Swedish high school students’ written production
No full textFemale students have long had a perceived advantage over male students in second language ac-quisition. In Swedish schools, the girls have outperformed the boys in the subject of English since the end of the Second World War, but the female students’ edge over the male students has diminished considerably over time. This essay aims to find out if there are any differences in lin-guistic ability between the two genders. The study uses a T-unit based syntax analysis in order to quantify the level of syntactic maturity that Swedish high school students possess, using data drawn from the Uppsala Learner English Corpus. Furthermore, the study aims to research gen-der-based stylistic differences and risk-taking behavior in the student’s writing. The results show that there are differences in syntactic maturity between the genders, as the female students in junior high school and the male students in senior high school outperform their respective counterparts, particularly in the indices based on error-free T-units. In addition, there are also stylistic disparities, as the female students have a greater focus on personalized ac-counts in their writing and the male students in junior high school have a very sparse and concise style of writing. The conclusion is drawn that while there are differences in syntactic maturity between boys and girls, the syntactic indices cannot accurately display the sophistication of the students’ writing and consequently should only be used in conjunction with more qualitative measures. Finally, while the study is not able to discern risk-taking in the students’ writing, the author concludes that risk-taking is an important factor in second language acquisition, especially considering the fact that the Swedish curricula in junior and senior high school English have a strong focus on communicative competence
Spatial distribution of water level impacting back-barrier bays
No full text© The Author(s), 2019. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Aretxabaleta, A. L., Ganju, N. K., Defne, Z., & Signell, R. P. Spatial distribution of water level impacting back-barrier bays. Natural Hazards and Earth System Sciences, 19(8), (2019): 1823-1838, doi: 10.5194/nhess-19-1823-2019.Water level in semi-enclosed bays, landward of barrier islands, is mainly driven by offshore sea level fluctuations that are modulated by bay geometry and bathymetry, causing spatial variability in the ensuing response (transfer). Local wind setup can have a complementary role that depends on wind speed, fetch, and relative orientation of the wind direction and the bay. Bay area and inlet geometry and bathymetry primarily regulate the magnitude of the transfer between open ocean and bay. Tides and short-period offshore oscillations are more damped in the bays than longer-lasting offshore fluctuations, such as a storm surge and sea level rise. We compare observed and modeled water levels at stations in a mid-Atlantic bay (Barnegat Bay) with offshore water level proxies. Observed water levels in Barnegat Bay are compared and combined with model results from the Coupled Ocean–Atmosphere–Wave–Sediment Transport (COAWST) modeling system to evaluate the spatial structure of the water level transfer. Analytical models based on the dimensional characteristics of the bay are used to combine the observed data and the numerical model results in a physically consistent approach. Model water level transfers match observed values at locations inside the bay in the storm frequency band (transfers ranging from 50 %–100 %) and tidal frequencies (10 %–55 %). The contribution of frequency-dependent local setup caused by wind acting along the bay is also considered. The wind setup effect can be comparable in magnitude to the offshore transfer forcing during intense storms. The approach provides transfer estimates for locations inside the bay where observations were not available, resulting in a complete spatial characterization. An extension of the methodology that takes advantage of the ADCIRC tidal database for the east coast of the United States allows for the expansion of the approach to other bay systems. Detailed spatial estimates of water level transfer can inform decisions on inlet management and contribute to the assessment of current and future flooding hazard in back-barrier bays and along mainland shorelines.This work was supported by the US Geological Survey, Coastal and Marine Hazards/Resources Program
Intelligent Equalisation Principles and Techniques for Minimising Masking when Mixing the Extreme Modern Metal Genre.
No full textThe intensity, complexity and energy of performance, combined with the power and density of the tones involved are characteristics of the extreme metal genre. These characteristics present numerous problems when striving to achieve the clarity, definition and hyper-realism of performance required for this genres production. Avoiding masking in a mix is a fundamental
aspect of clarity, definition, intelligibility and perceived loudness and due to the fact that masking especially occurs in a dense mix, and is more pronounced in low frequencies, is particularly applicable to mixing the downtuned extreme metal genre. Masking in simple terms is the ability of frequencies of one sound to obscure or inhibit (i.e. mask) the frequencies of
another sound. This paper will draw upon the first author’s eight years of experience producing within the metal genre, including releases through Sony and Universal and working with the likes of Colin Richardson and Andy Sneap
Advancing coastal ocean modelling, analysis, and prediction for the US Integrated Ocean Observing System
No full textThis paper outlines strategies that would advance coastal ocean modeling, analysis and prediction as a complement to the observing and data management activities of the coastal components of the U.S. Integrated Ocean Observing System (IOOS®) and the Global Ocean Observing System (GOOS). The views presented are the consensus of a group of U.S. based researchers with a cross-section of coastal oceanography and ocean modeling expertise and community representation drawn from Regional and U.S. Federal partners in IOOS. Priorities for research and development are suggested that would enhance the value of IOOS observations through model-based synthesis, deliver better model-based information products, and assist the design, evaluation and operation of the observing system itself. The proposed priorities are: model coupling, data assimilation, nearshore processes, cyberinfrastructure and model skill assessment, modeling for observing system design, evaluation and operation, ensemble prediction, and fast predictors. Approaches are suggested to accomplish substantial progress in a 3-8 year timeframe. In addition, the group proposes steps to promote collaboration between research and operations groups in Regional Associations, U.S. Federal Agencies, and the international ocean research community in general that would foster coordination on scientific and technical issues, and strengthen federal-academic partnerships benefiting IOOS stakeholders and end users.Peer reviewe
Collaboration tools and techniques for large model datasets
No full textAuthor Posting. © The Author(s), 2007. This is the author's version of the work. It is posted here by permission of Elsevier B.V. for personal use, not for redistribution. The definitive version was published in Journal of Marine Systems 69 (2008): 154-161, doi:10.1016/j.jmarsys.2007.02.013.In MREA and many other marine applications, it is common to have multiple models running with different grids, run by different institutions. Techniques and tools are described for low-bandwidth delivery of data from large multidimensional data sets, such as those from meteorological and oceanographic models, directly into generic analysis and visualization tools. Output is stored using the NetCDF CF Metadata Conventions, and then delivered to collaborators over the web via OPeNDAP. OPeNDAP datasets served by different institutions are then organized via THREDDS catalogs. Tools and procedures are then used which enable scientists to explore data on the original model grids using tools they are familiar with. It is also low-bandwidth, enabling users to extract just the data they require, an important feature for access from ship or remote areas. The entire implementation is simple enough to be handled by modelers working with their webmasters – no advanced programming support is necessary.S. Carniel was partially supported by the Office of Naval Research (ONR grant number N00014-05-1-0730). I. Janekovic was supported by the Croatian Ministry of Science, Education and Sport (grant number 0098113)
Modelling the Rhine ROFI on a non-straight coast
No full textAdditional thesis - The Rhine river outflow has a major impact on the North Sea in front of the Dutch coast. It creates the Rhine ROFI (region of freshwater influence), a very complex three-dimensional volume of water with a relatively low salinity. Many researches have been conducted on this phenomenon. Now another complex factor is added: a non-straight coastline. The specific case of the Sand Engine, a sandbar-shaped peninsula in front of the Holland coast, is studied. The objective is to identify changes in the Rhine ROFI caused by the Sand Engine and their possible causes. Simpson (Simpson, et al., 1993) and De Boer (2008) have identified several mechanisms influencing the shape and size of the Rhine ROFI. The major ones are: the deflection of the fresh water jet from the river Rhine through the Coriolis force towards the north forming a ‘coastal river’ of fresh water, advection due to tidal propagation, density currents as a consequence of horizontal density gradients, tidal straining and tidal mixing. Fortnightly and semidiurnal variations of velocities and stratification can be expected within the Rhine ROFI. Signell (1989) has had major contributions to the understanding of tidal propagation around coastal headlands. In his work a categorization is made for different combinations of tidal conditions and headland shapes. Within this categorization the Sand Engine is seen as a rather small and streamlined headland. Flow separation may be expected with a stagnant lee-side eddy forming each tidal period. These researches cover the main domain of interest of this thesis. An extension is made by exploring the baroclinic effects of the perturbation of the coast to the Rhine ROFI. For this purpose a numerical model was set up. In essence the original model De Boer used in his dissertation was applied. The Sand Engine was added as a blunt rectangular shape at the same distance from the river mouth as in reality. No numerical problems were found after adapting the model. The performance of the model was successfully verified by comparing time-averaged salinity distributions to figures in De Boer’s work. The Rhine ROFI and the ‘coastal river’ remain largely unchanged, comparing outcomes of the models with and without the Sand Engine. On a more detailed scale some interesting phenomena can be distinguished. During both neap and spring tide a fresh water feature forms ahead of high tide at the location of the Sand Engine. The offset of the fresh water feature has a barotropic origin, being generated by a strong current at the southwest corner of the Sand Engine. Under neap tide conditions this fresh water feature grows in the offshore direction, whereas this does not occur for spring tide conditions. This offshore advection is a baroclinic effect as such widespread offshore velocities involved with the offshore advection of fresh water were not found under barotropic conditions. A possible explanation of the offshore velocities is the strength of the tidal straining effect, being enforced by the stronger vertical density gradient when the fresh water is located at the Sand Engine. Tidal mixing is larger under spring conditions, preventing tidal straining from happening, explaining why offshore-directed velocities and subsequent offshore fresh water advection are not found in the results. In this thesis a simplified approach has been applied. Therefore the results must be treated with care under the likely possibility that flow mechanisms have been altered, enhanced or ruled out. However, the results do show the likely importance of baroclinic effects. These effects may have large consequences on the hydrodynamics in the area surrounding the Sand Engine. Therefore it is recommended to perform additional research on this topic.Civil Engineering and GeosciencesHydraulic EngineeringCIE5050-0
Variational analysis of drifter positions and model outputs for the reconstruction of surface currents in the central Adriatic during fall 2002
No full textAuthor Posting. © American Geophysical Union, 2008. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Journal of Geophysical Research 113 (2008): C04004, doi:10.1029/2007JC004148.In this paper we present an application of a variational method for the reconstruction of the velocity field in a coastal flow in the central Adriatic Sea, using in situ data from surface drifters and outputs from the ROMS circulation model. The variational approach, previously developed and tested for mesoscale open ocean flows, has been improved and adapted to account for inhomogeneities on boundary current dynamics over complex bathymetry and coastline and for weak Lagrangian persistence in coastal flows. The velocity reconstruction is performed using nine drifter trajectories over 45 d, and a hierarchy of indirect tests is introduced to evaluate the results as the real ocean state is not known. For internal consistency and impact of the analysis, three diagnostics characterizing the particle prediction and transport, in terms of residence times in various zones and export rates from the boundary current toward the interior, show that the reconstruction is quite effective. A qualitative comparison with sea color data from the MODIS satellite images shows that the reconstruction significantly improves the description of the boundary current with respect to the ROMS model first guess, capturing its main features and its exchanges with the interior when sampled by the drifters.Four of the authors are supported by the
Office of Naval Research, V.T. and A.G. under grants N00014-05-1-0094
and N00014-05-1-0095, P.M.P. under grant N00014-03-1-0291, and S.C.
under grant N00014-05-1-0730. CNR-ISMAR
activity was partially supported by P.O.R. ‘‘CAINO’’ (Regione Puglia),
VECTOR (Italian MIUR) project, and ECOOP (EU project)
Determining potential for pollutant impacts in dynamic coastal waters: comparing morphological settings
No full textThe coastal focus and beach culture of Australia’s population in general, and the people of New South Wales in particular, mean that coastal systems are both highly prized and subjected to great pressures. The vast majority of the wastewater generated by the 7.3 million people of New South Wales is discharged directly to the ocean. The dispersion and fate of waterborne pollutants and their potential to impact coastal ecosystems are fundamentally determined by the dynamics of the coastal boundary layer (CBL). This turbulent interface between the coastline and the deep oceans is defined and classified for the first time in this thesis. Coastal morphologies and changes in the orientation of the coastline promote turbulence and strong gradients with extreme variability and heterogeneity over a broad range of scales. Conceptual models are presented to characterise New South Wales coastal boundary layer processes.
The broad aims of this thesis are to investigate the coastal boundary layer processes that affect dispersal and advection of pollutants, and to develop conceptual models and tools to facilitate coastal management.
Remote sensed ocean colour and sea surface temperature observations define meso-scale CBL phenomena, and this study demonstrates their application to support management decisions in relation to marine algal (phytoplankton) blooms. However, considerable scope exists to improve regional algorithms to deliver better ocean colour products for the optically complex (Case 2) waters of the inner coastal boundary layer.
Past failures to consider the CBL (morphological) settings of pollutant discharges to coastal waters have led to inefficient pollutant discharge systems and potential environmental impacts. Two case studies, investigate the principal forcing mechanisms and demonstrate the importance of morphology in controlling the dispersion and retention times of pollutants.
The first case study is focused on Sydney coastal waters where pollutant loadings are greater in magnitude and different in character than elsewhere in New South Wales. Here population pressures generate large wastewater loadings but the distances to offshore discharge locations are large compared to the scale of coastal roughness (headlands and bays) and the water is deep, thus reducing the risk of local retention of pollutants and increasing the potential for rapid dilution. By considering simulations of near field effluent plume behaviour in relation to long term ambient nutrient patterns specific periods of the year and depth intervals have been identified when outfalls would have an increased opportunity to influence bloom development, especially the upper half of the water column during late summer. However, algal blooms appear to be principally driven by seasonal oceanic nutrient enrichment. The research presented in this thesis, together with companion research previously published by the author and routine ongoing monitoring, indicate the viability of disposal of the Sydney’s excess sewage effluent (after source control and re-use options have been exhausted) via existing deepwater outfalls.
In contrast, inner CBL settings with coastal irregularities (e.g. headlands and bays) have a greater propensity to trap pollutants. A new hydrodynamically relevant morphological classification of New South Wales bays, headlands and islands provides both broad context for case studies and guides preliminary assessments for other locations. This classification reveals a borderline propensity for flow separation and re-circulation in the lee of Corambirra Point which is the focus of the second case study off Coffs Harbour in northern NSW. Direct observations and 3D finite difference hydrodynamic (Eulerian) and particle tracking (Lagrangian) model simulations quantify transient re-circulation associated with local current accelerations and a persistent shear zone located in the wake to the south of Corambirra Point. The flux of ambient water across the prescribed outfall alignment increases eighteen fold, over a shear zone spanning a cross-shore distance of just 1.4km (from 1.6km to 3km offshore). In contrast, the potential for re-entrainment and trapping of effluent in transient re-circulation cells was demonstrated to be insignificant. The proposed location of the outfalls was 1.5km offshore whereas the greatest gain per unit extension of the proposed discharge point coincides with the centre of the shear zone located ~2km offshore.
These case studies illustrate specific coastal boundary layer effects and indicate how an understanding of the spatial and temporal scales of these effects can be used to target more specific assessments of potential pollutant impacts. Simple morphological risk assessment tools are also presented to identify factors and processes which limit the exposure of sensitive environments to high pollutant concentrations and loads. Eddy retention effects are generally not incorporated in existing near field models but potential re-entrainment effects in wake zones can be assessed through the eddy retention value, which is introduced in this thesis. Although the approach presented here is focused on New South Wales coastal waters, the framework serves as a basis for general application elsewhere, and as a foundation for further refinement for application to NSW coastal waters.
Existing scientific literature indicates that coastal boundary layer processes also shape the distributions of the biological species and communities. This further motivates the development of a process based understanding of coastal boundary layer dynamics as a fundamental platform to support environmental protection and biodiversity conservation initiatives
High-resolution mapping of Bora winds in the northern Adriatic Sea using synthetic aperture radar
No full textAuthor Posting. © American Geophysical Union, 2010. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Journal of Geophysical Research 115 (2010): C04020, doi:10.1029/2009JC005524.The Adriatic Sea is regularly subjected to strong Bora wind events from the northeast during winter. The events have a strong effect on the oceanography in the Adriatic, driving basin-scale gyres that determine the transport of biogeochemical material and extracting large amounts of heat. The Bora is known to have multiple surface wind jets linked to the surrounding orography and have been the focus of many studies, but it has not been possible to describe the detailed spatial structure of these jets by in situ observations. Using high-resolution spaceborne RADARSAT-1 synthetic aperture radar (SAR) images collected during an active Bora period (23 January–16 February 2003), we created a series of high-resolution (300 m) maps of the wind field. The obtained winds show reasonable agreement with several in situ wind observations, with an RMS wind speed error of 3.6 m/s, slightly higher than the 2–3 m/s errors reported in previous studies. These SAR images reveal the spatial structure of the Bora wind in unprecedented detail, showing several new features. In the Senj region of Croatia, several images show rhythmic structure with wavelengths of 2–3 km that may reflect Bora pulsation seen at fixed locations by previous investigators. Along the Italian coast, several images show a wide (20–30 km) band of northwesterly winds that abruptly change to the northeasterly Bora winds further offshore. Meteorological model results suggest that these northwesterly winds are consistent with those of a barrier jet forming along the Italian Apennine mountain chain
