An Evaluation of a High-Resolution Operational Wave Forecasting System in the Adriatic Sea PDF Download

Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 20

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Book Description
The SWAN (Simulating Waves Nearshore) wave model using wind inputs generated by the ALADIN 8-km, operational high-resolution, atmospheric model was run in real-time to provide surface waves forecast for the semi-enclosed Adriatic Sea in support of the "Dynamics of the Adriatic in Real-Time" (DART) field experiments. Together with predictions from other wave and wind models, the successful prediction of a high sea-state event by this model led to a real-time shifting of planned operations while at sea, allowing five ADCP moorings to be deployed just before a bora storm and associated storm waves arrived. The model was also able to simulate the spatial gradients in significant wave height observed by in-situ and remote-sensing measurements for a particular sirocco storm case study, providing an additional perspective in aiding interpretation of the model output of features. To further quantify prediction skill, the wave forecast performance over a 12-month period was evaluated against in-situ and altimeter measurements over the region. Correlation coefficients between forecast and in-situ measured significant wave heights were from 0.82 to 0.91 for the 24-h forecast and from 0.78 to 0.88 for the 48-h forecast. However, best-fit slope comparisons with in-situ wave data at five coastal locations show the forecast wave heights were underpredicted by 10% to 30%. Best-fit slope comparisons between modeled wind speeds, U10, and significant wave heights. Hs and altimeter-derived measurements show that model U10 was about 4% underpredicted, but Hs, was underpredicted by an average of 30%. The underprediction of SWAN Hs has a very significant location-dependent geographical variation ranging from 10% to over 50%.

Author: Ivica Vilibić
Publisher: Birkhäuser
ISBN: 9783030119577
Category : Science
Languages : en
Pages : 0

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Book Description
The Mediterranean Sea, as a “centre” of the ancient world, has been early recognized as a laboratory basin for a variety of atmospheric, ocean and climate studies. Its uniqueness is manifested in its geographical position, a mid-latitude region connecting three continents, orography that affects cyclogenesis, precipitation and winds, ocean bathymetry that is shaped by narrow and shallow straits, passages and sills, and other. Its both atmospheric and oceanic climate is distinctive and, while differing substantially from neighbouring continents and oceans, it strongly interferes and shapes their properties. One of such adjacent basins is the Black Sea, which is, albeit minor in quantity, providing a noteworthy impact to the Mediterranean and vice versa. This topical volume of Pure and Applied Geophysics is presenting recent investigations of atmospheric and ocean properties, processes and climate of both basins, being inspired by presentations given in the Joint Congress of the 6th International Conference on Meteorology and Climatology of the Mediterranean & Challenges in Meteorology 5, held in Zagreb, Croatia, on 20-22 February 2017. The volume comprises 22 papers that are classified in three research categories: (1) storms, extremes and mesoscale processes, (2) atmospheric climate, variability and climate change, and (3) ocean climate and variability. The papers investigate processes occurring over a variety of spatial and temporal scales, from hemispheric processes that drive the observed changes in the Mediterranean and Black Sea, through phenomena that are influencing the whole basin or its sub-basins, to local and mesoscale extreme events that are affecting large cities and local populations in the region. The volume is of interest to atmospheric and oceanic researchers involved in a variety of processes that are occurring over the Mediterranean and Black Sea region. This particularly refers to young researchers and PhD students that are yet to enter to research of this unique and exciting region full of challenges that need an interdisciplinary, innovative and state-of-the-art approaches in solving actual research problems.

Author: Carlos Guedes Soares
Publisher: CRC Press
ISBN: 0203105184
Category : Technology & Engineering
Languages : en
Pages : 698

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Book Description
Maritime Engineering and Technology includes the papers from the 1st International Conference on Maritime Technology and Engineering (MARTECH 2011, Lisbon, Portugal, 10-12 May 2011). MARTECH 2011 was held to commemorate 100 years of the Instituto Superior Tico (IST) in Lisbon, and the contributions in the present volume reflect the

Author: C. Guedes Soares
Publisher: CRC Press
ISBN: 1315647850
Category : Technology & Engineering
Languages : en
Pages : 1030

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Book Description
Renewable Energies Offshore includes the papers presented in the 1st International Conference on Renewable Energies Offshore (RENEW2014), held in Lisbon, 24-26 November 2014. The conference is a consequence of the importance of the offshore renewable energies worldwide and an opportunity to contribute to the exchange of information on the dev

Author: S.C. Bhargava
Publisher: CRC Press
ISBN: 0415621461
Category : Computers
Languages : en
Pages : 700

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Book Description
This book, written for the benefit of engineering students and practicing engineers alike, is the culmination of the author's four decades of experience related to the subject of electrical measurements, comprising nearly 30 years of experimental research and more than 15 years of teaching at several engineering institutions. The unique feature of this book, apart from covering the syllabi of various universities, is the style of presentation of all important aspects and features of electrical measurements, with neatly and clearly drawn figures, diagrams and colour and b/w photos that illustrate details of instruments among other things, making the text easy to follow and comprehend. Enhancing the chapters are interspersed explanatory comments and, where necessary, footnotes to help better understanding of the chapter contents. Also, each chapter begins with a "recall" to link the subject matter with the related science or phenomenon and fundamental background. The first few chapters of the book comprise "Units, Dimensions and Standards"; "Electricity, Magnetism and Electromagnetism" and "Network Analysis". These topics form the basics of electrical measurements and provide a better understanding of the main topics discussed in later chapters. The last two chapters represent valuable assets of the book, and relate to (a) "Magnetic Measurements", describing many unique features not easily available elsewhere, a good study of which is essential for the design and development of most electric equipment – from motors to transformers and alternators, and (b) "Measurement of Non-electrical Quantities", dealing extensively with the measuring techniques of a number of variables that constitute an important requirement of engineering measurement practices. The book is supplemented by ten appendices covering various aspects dealing with the art and science of electrical measurement and of relevance to some of the topics in main chapters. Other useful features of the book include an elaborate chapter-by-chapter list of symbols, worked examples, exercises and quiz questions at the end of each chapter, and extensive authors' and subject index. This book will be of interest to all students taking courses in electrical measurements as a part of a B.Tech. in electrical engineering. Professionals in the field of electrical engineering will also find the book of use.

Author: Gaurav Singhal
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Book Description
Real-time wave forecasts are critical to a variety of coastal and offshore opera- tions. NOAA's global wave forecasts, at present, do not extend into many coastal regions of interest. Even after more than two decades of the historical Exxon Valdez disaster, Cook Inlet (CI) and Prince William Sound (PWS) are regions that suffer from a lack of accurate wave forecast information. This dissertation develops high- resolution integrated wave forecasting schemes for these regions in order to meet the critical requirements associated with shipping, commercial and sport fishing vessel safety, and oil spill response. This dissertation also performs a detailed qualitative and quantitative assessment of the impact of various forcing functions on wave pre- dictions, and develops maps showing extreme variations in significant wave heights (SWHs). For instance, it is found that the SWH could vary by as much as 1 m in the northern CI region in the presence of currents (hence justifying the need for integration of the wave model with a circulation model). Such maps can be useful for several engineering operations, and could also serve as guidance tool as to what can be expected in certain regions. Aside from the system development, the issue of forecast reliability is also addressed for PWS region in the context of the associated uncertainty which confronts the manager of engineering operations or other planners. For this purpose, high-resolution 36-h daily forecasts of SWHs are compared with measurements from buoys and satellites for about a year. The results show that 70% of the peak SWHs in the range 5-8 m were predicted with an accuracy of 15% or less for a forecast lead time of 9 h. On average, results indicate 70% or greater likelihood of the prediction falling within a tolerance of ±(1*RMSE) for all lead times. This analysis could not be performed for CI due to lack of data sources.

Author: Elena Pallarès López
Publisher:
ISBN:
Category :
Languages : en
Pages : 194

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Book Description
It is widely known that wind and wave predictions in the nearshore are less precise for semi enclosed domains than in the open ocean. The Catalan coast is a clear example of this situation, with a wave climate controlled by short fetches, complex bathymetry, high wind field variability in time and space, and sea and swell waves combined that generate bimodal spectra. These characteristics, typical for a semi-enclosed basin, limit the reliability of wave predictions in the area, with errors on the significant wave height around 10% and a clear under-prediction of the wave period with errors around 30%. The motivation of this work is to improve the actual wave forecasting abilities for the Catalan Coast using the SWAN v.4091 wave model. In order to achieve this goal, three working lines are considered: (1)adapting the model to the Catalan coast conditions, tuning the wave growth rates included in the model to better reproduce the observed values, (2) evaluate the effect of the currents and wind into the wave field by using a coupled system and (3) consider the use of unstructured grids as an alternative to the traditionally nested systems in order to obtain high resolution wave forecasts in coastal areas reducing the computational time and avoiding the use of internal boundary conditions with their associated errors. The results obtained support previous studies where the limited ability of the models to reproduce wave growth rates in young seas have been detected. The whitecapping term correction proposed in this document helps reducing under-prediction of the wave period observed with almost no effect on the significant wave height. This correction can be applied to similar environments. However, the proposed formulation is only suitable for the early stages of generation and should be discontinued after waves reach a certain maturity. Two coupling strategies are considered, a one-way coupling where current fields are directly introduced into the wave model, and a two-way coupling where the waves, currents and winds models run in parallel. The effects of the coupling are evaluated during calm periods but also during energetic events. The results show that during calm conditions the coupling does hardly improve the results while during energetic events, such as superficial currents intensifications or wind jet events, the coupling has greater importance. However, the two-way coupling has extremely high computational requirements, not always available. In this sense, the use of unstructured grids as an alternative to the traditional nested systems is presented. The main benefit of unstructured grids is that allows working with a single grid with different resolutions in each sub-domain, improving the resolution in coastal areas. Other advantage is the capacity to better reproduce the sharp coastline and the areas around the islands. The design of unstructured grids has been shown as one of the most delicate parts of this methodology, requiring special attention for the grid generation criteria. The validation of the results, performed with buoy measurements in the nearshore but also for the entire domain with altimetry measurements, allows stating that unstructured grids perform correctly in the study area. Finally, the proposed work suitability for an operational forecasting system has been considered. The whitecapping term modification is proven to be decisive in the quality of the wave forecast, while the coupling is not always recommended depending on computational capabilities. The use of unstructured grids with a regional triangular mesh covering the entire Western Mediterranean sea is considered as the first option, providing accurate high resolution wave conditions near the coast with a clear reduction of the computational time in comparison with a traditional nested system.

Author: G. J. Komen
Publisher: Cambridge University Press
ISBN: 0521470471
Category : Science
Languages : en
Pages : 558

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Book Description
A comprehensive introduction and reference prepared by the world's leading ocean wave modellers.

Author: Madhav L. Khandekar
Publisher: Springer Science & Business Media
ISBN: 1461389526
Category : Science
Languages : en
Pages : 223

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Book Description
This monograph is an attempt to compile the present state of knowledge on ocean wave analysis and prediction. The emphasis of the monograph is on the development of ocean wave analysis and predic tion procedures and their utility for real-time operations and appli cations. Most of the material in the monograph is derived from journal articles, research reports and recent conference proceedings; some of the basic material is extracted from standard text books on physical oceanography and wind waves. Ocean wave analysis and prediction is becoming an important activity in the meteorological and oceanographic services of many countries. The present status of ocean wave prediction may be compar able to the status of numerical weather prediction of the mid-sixties and early seventies when a number of weather prediction models were developed for research purposes, many of which were later put into operational use by meteorological services of several countries. The increased emphasis on sea-state analysis and prediction has created a need for a ready reference material on various ocean wave analysis and modelling techniques and their utility. The present monograph is aimed at fulfilling this need. The monograph should prove useful to the ocean wave modelling community as well as to marine forecasters, coastal engineers and offshore technologists. The monograph could also be used for a senior undergraduate (or a first year graduate) level course in ocean wave modelling and marine meteorology.

Author: Tong Lee
Publisher: Frontiers Media SA
ISBN: 2889631192
Category : Science
Languages : en
Pages : 629

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Book Description
This eBook is a collection of articles from a Frontiers Research Topic. Frontiers Research Topics are very popular trademarks of the Frontiers Journals Series: they are collections of at least ten articles, all centered on a particular subject. With their unique mix of varied contributions from Original Research to Review Articles, Frontiers Research Topics unify the most influential researchers, the latest key findings and historical advances in a hot research area! Find out more on how to host your own Frontiers Research Topic or contribute to one as an author by contacting the Frontiers Editorial Office: frontiersin.org/about/contact.