Download or read book Acoustic Monitoring of Global Ocean Climate written by and published by . This book was released on 1999 with total page 10 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Acoustic Monitoring of Global Ocean Climate written by United States. Defense Advanced Research Projects Agency and published by . This book was released on 1996* with total page 8 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Acoustic Monitoring of Global Ocean Climate written by and published by . This book was released on 1996 with total page 8 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Acoustic Monitoring of Global Ocean Variability written by and published by . This book was released on 1993 with total page 39 pages. Available in PDF, EPUB and Kindle. Book excerpt: The ocean circulation is known to be a central element in determining the present climate state and to be crucial in understanding how it might change in the future. However, our current understanding of the ocean is so primitive that forecasts of future climate states much be regarded as mainly speculative. Central to the problem is the very great difficulty of observing the state of the ocean today, and of determining whether it is changing to any significant extent. The concept for Acoustic Thermometry of Ocean Climate being described by this document focuses on the critical role of the world's oceans in the process of global change. A research and engineering program to create a network of acoustic transmission paths represents the first step to measure long-term temperature change in the ocean (and hence by inference, atmospheric and climatic trends). This network can build on the results of The Heard Island Feasibility Test, of using very long-range underwater sound transmissions to measure oceanic temperature on basin scales. It involves a multiyear program to monitor the ocean on a global basis by installing a system of acoustic sources and receives at sites that provide adequate spatial sampling, and are technically, politically and logistically feasible.
Download or read book Fram Strait Acoustic Monitoring for Ocean Climate Studies written by and published by . This book was released on 1997 with total page 52 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Fram Strait Acoustic Monitoring for Ocean Climate Studies written by and published by . This book was released on 1997 with total page 52 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Real Time System for Practical Acoustic Monitoring of Global Ocean Temperature written by and published by . This book was released on 1994 with total page 108 pages. Available in PDF, EPUB and Kindle. Book excerpt: The acoustic multipaths from the Kaneohe source have been identified at one SOSUS station using a ray tracing algorithm called ZRAY. This is the furthest, 4000 km, that ray theory has been successfully used to understand acoustic propagation in the ocean. This further validates that acoustic thermometry is valid at basin-scales and that changes in the travel time from the Kaneohe source are not due to changes in the multipaths. FSU designed an acoustic tomography assimilation scheme for a reduced gravity model, but with spatially variable density. The goal of this effort is to estimate the time independent density field in the upper northeast Pacific ocean. A second test cruise was conducted at the AUTEC Range in August to verify SSAR performance with a 70 Hz source. This test consisted of the deployment of a normal SSAR (snubber design) and a moored SSAR. The moored SSAR was deployed on a subsurface mooring, thus removing surface generated noise. A 70 Hz source transmitted an M- sequence signal and both systems recorded data on hard disk. The normal SSAR also telemetered processed data. In addition, the SSAR acoustic navigation system was tested against the AUTEC Range system. All data were successfully collected and processing of this information is ongoing.
Download or read book Real Time System for Practical Acoustic Monitoring of Global Ocean Temperature Volume 3 written by and published by . This book was released on 1994 with total page 199 pages. Available in PDF, EPUB and Kindle. Book excerpt: Work continues on all GAMOT Tasks as described in ARPA Grant No: MDA972-93-1-004. (1) Task A. Task A work remains on schedule and we have completed the following work: We are writing a new eigenray finder for use in identifying the paths which sound take from sources to the surface suspended acoustic receivers; A theoretical investigation has been conducted which has found that it is possible that ray theory can be extended to acoustic frequencies below 100 Hz; A new parabolic approximation to the acoustic wave equation has been developed. Unlike all previous parabolic approximations, the new approximation predicts delays of acoustic pulses with little error; The acoustic multipaths from the Kaneohe source have been identified at one SOSUS station using a ray tracing algorithm called ZRAY. This was a breakthrough since this is the furthest, 4000 km, that ray theory has been successfully used to understand acoustic propagation in the ocean; (2) Task B. Task B tasks and deliverables are on schedule. We have completed writing of a manuscript detailing the travel time anomaly estimates using a reduced gravity model of the northeast Pacific. We have designed an acoustic tomography assimilation method for a similar model but with spatially variable density. The plan for monitoring the Pacific Ocean for long term change is contained in the Task B section; (3) Task C. Fabrication of ten operational SSARs is continuing. Two units are being prepared for a test cruise at the AUTEC Range in August and two units are being prepared for testing in the Pacific in November. No significant delays or problems ahve been encountered; and (4) Task D. The 70 Hz source proposal was submitted to ARPA on April 19, 1994. No action has yet been taken on the proposal.
Download or read book California Acoustic Thermometry of Ocean Climate ATOC Program and Marine Mammal Research MMRP Program Monterey County written by and published by . This book was released on 1995 with total page 446 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Kauai Acoustic Thermometry of Ocean Climate ATOC Project and Marine Mammal Research Program MMRP written by and published by . This book was released on 1995 with total page 616 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Understanding Global Climate Change with Ocean Acoustic Tomography and Models written by and published by . This book was released on 1992 with total page 10 pages. Available in PDF, EPUB and Kindle. Book excerpt: Paleoclimate inferred from the Vostok ice core provides tantalizing evidence that increases in atmospheric CO2 are dynamically linked with increases in atmospheric temperature (Jouzel et al., 1987; Barnola et al., 1987; Genthon et al., 1987). However, the mechanisms responsible for the temporal and spatial scales of the accompanying temperature change are not understood because, in part, the ocean's role is not well understood. New technology is required to see inside the global oceans where vasts amount of heat are redistributed and eventually exchanged with the atmosphere. Waves and other features at large scales, approximately 100 to 10,000 km, having time scales less than centuries are virtually unexplored but these scales are important for understanding climate change (Gill, 1982; Philander, 1990). We are developing novel acoustic instruments that have the potential for measuring these scales in the global oceans in real-time. The cost for these measurements is projected to be less than the costs of mapping temperature and other variables in the atmosphere (Spiesberger, 1992). (MM).
Download or read book Fram Strait Acoustic Monitoring for Ocean Climate Studies written by and published by . This book was released on 1997 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Acoustic Thermometry of Ocean Climate written by Forsyth Patterson Kineon and published by . This book was released on 1996 with total page 116 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Ocean s Role in Global Change written by National Research Council and published by National Academies Press. This book was released on 1994-02-01 with total page 96 pages. Available in PDF, EPUB and Kindle. Book excerpt: What role does the ocean play in global climate change? Although not fully understood, there is general agreement that it is significant. Therefore, the scientific community has initiated large-scale research programs based on studies of the ocean and its relation to global climate and climate-related processes. This volume provides brief summaries and reports on the progress of the major oceanographic research programs. It looks at both programs that study processes that occur over periods ranging from days to hundreds of yearsâ€"the contemporary systemâ€"and those that seek to understand long-term variations ranging from thousands to millions of yearsâ€"the geological perspective.
Download or read book International Regulation of Underwater Sound written by Elena McCarthy and published by Springer Science & Business Media. This book was released on 2007-05-08 with total page 295 pages. Available in PDF, EPUB and Kindle. Book excerpt: Numerous incidents suggest that man-made sound injures and can kill marine mammals. This book offers an objective look at how ocean noise should be addressed given the lack of regulatory structure and the scientific uncertainty over the effects of noise on marine life. It is an essential text for policymakers, governments and NGOs, biologists, environmental activists, , oceanographers, and those in the shipping, engineering, and offshore oil and gas industries.
Download or read book Planning of Deployment of an Autonomous Source for Year Round Acoustic Monitoring of the Arctic Ocean written by A. N. Gavrilov and published by . This book was released on 1995 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Planning of a year-round experiment on trans-Arctic acoustic transmission in the framework of the program Arctic Climate Observation using Underwater Sound" (ACOUS) is a complex problem involving, not only, scientific and technical issues, but requiring consideration, also, of the financial aspects. According to the ACOUS proposal, the NRAD's vertical array is one which can be used as the first receiving system for the year-round experiment, and this array should be deployed in the Lincoln Sea in the spring of 1996. Therefore, the main problem at the first stage of designing the experiment is to develop an optimum scheme for trans-Arctic acoustic transmissions to the Lincoln Sea.
Download or read book Underwater Acoustic Modeling and Simulation written by Paul C. Etter and published by CRC Press. This book was released on 2017-12-19 with total page 521 pages. Available in PDF, EPUB and Kindle. Book excerpt: Underwater Acoustic Modeling and Simulation, Fourth Edition continues to provide the most authoritative overview of currently available propagation, noise, reverberation, and sonar-performance models. This fourth edition of a bestseller discusses the fundamental processes involved in simulating the performance of underwater acoustic systems and emphasizes the importance of applying the proper modeling resources to simulate the behavior of sound in virtual ocean environments. New to the Fourth Edition Extensive new material that addresses recent advances in inverse techniques and marine-mammal protection Problem sets in each chapter Updated and expanded inventories of available models Designed for readers with an understanding of underwater acoustics but who are unfamiliar with the various aspects of modeling, the book includes sufficient mathematical derivations to demonstrate model formulations and provides guidelines for selecting and using the models. Examples of each type of model illustrate model formulations, model assumptions, and algorithm efficiency. Simulation case studies are also included to demonstrate practical applications. Providing a thorough source of information on modeling resources, this book examines the translation of our physical understanding of sound in the sea into mathematical models that simulate acoustic propagation, noise, and reverberation in the ocean. The text shows how these models are used to predict and diagnose the performance of complex sonar systems operating in the undersea environment.
