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 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 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 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 Ocean Variability Acoustic Propagation written by J. Potter and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 599 pages. Available in PDF, EPUB and Kindle. Book excerpt: Fifteen years ago NATO organised a conference entitled 'Ocean Acoustic Modelling'. Many of its participants were again present at this variability workshop. One such participant. in concluding his 1975 paper, quoted the following from a 1972 literature survey: ' ... history presents a sad lack of communications between acousticians and oceanographers' Have we done any better in the last 15 years? We believe so, but only moderately. There is still a massive underdeveloped potential for acousticians and oceanographers to make significant progress together. Currently, the two camps talk together insufficiently even to avoid simple misun derstandings. such as those in Table 1. Table 1 Ocsanographic and acoustic jargon (from an idea by Pol/ardi Jargon Oceanographic use Acoustic use dbordB decibar (depth in m) decibel (energy level) PE primitive equations parabolic equations convergence zone converging currents converging rays (downwelling water) (high energy density) front thermohaline front wave, ray or time front speed water current speed sound propagation speed 1 The list goes on.
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 Spatial and Temporal Variability of Cross Basin Acoustic Ray Paths written by Coenraad M. Ort and published by . This book was released on 1990 with total page 84 pages. Available in PDF, EPUB and Kindle. Book excerpt: It was suggested by Munk and Forbes (1989) that climate induced changes in ocean temperature may be monitored by measurements of cross-basin acoustic travel time variability. The feasibility of such a monitoring system depends on the spatial and temporal variability of the cross-basin acoustic paths in the presence of ocean variability of many different scales. For this thesis the variations in arrival position, azimuthal arrival angle, ray trajectory and the corresponding changes in travel times along the three- dimensional multipaths due to meso- and gyre scale ocean temperature fluctuations were analyzed. Emphasis was placed on the acoustic paths from Heard Island in the Indian Ocean, the proposed location for the sound source, to the west coast of the United States. An optimal receiver site location was found to exist in the vicinity of Monterey Bay, California. The possibility of a proposed listening site location near Coos Bay, Oregon, was also examined. However, the ray paths to Coos Bay interact with the bottom frequently, thus rendering them less reliable. All the ray traces for this study were carried out using the recently upgraded Hamiltonian raytracing code HARPO, interfaced with output form the Semtner-Chervin eddy resolving global ocean general circulation model. This interface allows for a realistic simulation of the effects of meso- and gyre scale processes on the variability of the various cross-basin paths.
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1995 with total page 704 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Interacting Climates of Ocean Basins written by Carlos R. Mechoso and published by Cambridge University Press. This book was released on 2020-11-26 with total page 359 pages. Available in PDF, EPUB and Kindle. Book excerpt: A comprehensive review of interactions between the climates of different ocean basins and their key contributions to global climate variability and change. Providing essential theory and discussing outstanding examples as well as impacts on monsoons, it a useful resource for graduate students and researchers in the atmospheric and ocean sciences.
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 Naval Research Reviews written by and published by . This book was released on 1990 with total page 312 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Observing the Oceans in Real Time written by R. Venkatesan and published by Springer. This book was released on 2017-11-17 with total page 322 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides contributions from leading experts on the integration of novel sensing technologies to yield unprecedented observations of coupled biological, chemical, and physical processes in the ocean from the macro to micro scale. Authoritative entries from experts around the globe provide first-hand information for oceanographers and researchers looking for solutions to measurement problems. Ocean observational techniques have seen rapid advances in the last few years and this book addresses the need for a single overview of present and future trends in near real time and real time. First the past, present and future scenarios of ocean observational tools and techniques are elucidated. Then this book divides into three modes of ocean observations: surface, upper ocean and deep ocean. This is followed by data quality and modelling. Collecting a summary of methods and applications, this book provides first-hand information for oceanographers and researchers looking for solutions to measurement problems. This book is also suitable for final year undergraduate students or beginning graduate students in ocean engineering, oceanography and various other engineering students (such as Mechanical, Civil, Electrical, and Bioengineering) who are interested in specializing their skills towards modern measurements of the ocean.
Download or read book Department of Defense Appropriations for 1996 Quality of Life Personnel Policies National Guard pt 3 Commanders in Chief Pacific Command and United States Forces Korea European Command pt 4 Army programs Aviation written by United States. Congress. House. Committee on Appropriations. Subcommittee on National Security and published by . This book was released on 1996 with total page 950 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Department of Defense Appropriations for 1996 Quality of life senior enlisted advisors written by United States. Congress. House. Committee on Appropriations. Subcommittee on National Security and published by . This book was released on 1996 with total page 952 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Department of Defense Appropriations for 1996 written by United States. Congress. House. Committee on Appropriations. Subcommittee on National Security and published by . This book was released on 1996 with total page 958 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Natural Climate Variability on Decade to Century Time Scales written by National Research Council and published by National Academies Press. This book was released on 1996-08-30 with total page 645 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume reflects the current state of scientific knowledge about natural climate variability on decade-to-century time scales. It covers a wide range of relevant subjects, including the characteristics of the atmosphere and ocean environments as well as the methods used to describe and analyze them, such as proxy data and numerical models. They clearly demonstrate the range, persistence, and magnitude of climate variability as represented by many different indicators. Not only do natural climate variations have important socioeconomic effects, but they must be better understood before possible anthropogenic effects (from greenhouse gas emissions, for instance) can be evaluated. A topical essay introduces each of the disciplines represented, providing the nonscientist with a perspective on the field and linking the papers to the larger issues in climate research. In its conclusions section, the book evaluates progress in the different areas and makes recommendations for the direction and conduct of future climate research. This book, while consisting of technical papers, is also accessible to the interested layperson.
