Download or read book SOFAR Float Mediterranean Outflow Experiment Data from the First Year 1984 1985 written by and published by . This book was released on 1986 with total page 670 pages. Available in PDF, EPUB and Kindle. Book excerpt: In October, 1984, the Woods Hole Oceanographic Institution SOFAR float group began a three-year long field program to observe the low frequency currents in the Canary Basin. The principal scientific goal was to learn how advection and diffusion by these currents determine the shape and amplitude of the Mediterranean salt tongue. Fourteen floats were launched at a depth of 1100 min a cluster centered on 32N, 24W, and seven other floats were launched incoherently along a north/south line from 24N to 37N. At the same time investigators from Scripps Institution of Oceanography and the University of Rhode Island used four other SOFAR floats to tag a submesoscale lens of Mediterranean water. Slightly over twenty years of float trajectories were p reduced during the first year of the experiment. In this report we briefly describe the 1984 field operations and show the first year's SOFAR float data. Perhaps the most striking result is that westward flow within the Mediterranean salt tongue was found to be confined to a rather narrow jet {roughly 150 km in meridional extent) which had a mean speed of roughly 2 em s -l. To the north or south of this jet the mean flow was much weaker and eastward. This suggests that currents associated with the salt tongue itself {rather than the gyre scale circulation) may be most important for determining the salt distribution.
Download or read book SOFAR Float Mediterranean Outflow Experiment written by Marguerite E Zemanovic and published by . This book was released on 1990 with total page 854 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Sea Level Changes written by P. L. Woodworth and published by American Geophysical Union. This book was released on 1992-04-08 with total page 194 pages. Available in PDF, EPUB and Kindle. Book excerpt: Published by the American Geophysical Union as part of the Geophysical Monograph Series, Volume 69. The measurement of sea level is of fundamental importance to a wide range of research in climatology, oceanography, geology and geodesy. This volume attempts to cover many aspects of the field. The volume opens with a description by Bolduc and Murty of one of the products stemming from the development of tide gauge networks in the northern and tropical Atlantic. This work is relevant to the growth of the Global Sea Level Observing System (GLOSS), the main goal of which is to provide the world with an efficient, coherent sea level monitoring system for océanographie and climatological research. The subsequent four papers present results from the analysis of existing tide gauge data, including those datasets available from the Permanent Service for Mean Sea Level and the TOGA Sea Level Center. Two of the four, by Wroblewski and by Pasaric and Orlic, are concerned with European sea level changes, while Yu Jiye et al. discuss inter-annual changes in the Pacific, and Wang Baocan et al. describe variability in the Changjiang estuary in China. The papers by El-Abd and Awad, on Red Sea levels, are the only contributions to the volume from the large research community of geologists concerned with sea level changes.
Download or read book Journal of Physical Oceanography written by and published by . This book was released on 1997-05 with total page 1040 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Model of a Mediterranean Salt Lens in External Shear written by David Walsh and published by . This book was released on 1992 with total page 522 pages. Available in PDF, EPUB and Kindle. Book excerpt: A pair of simple models representing the interaction of a continuously stratified f-plane quasigeostrophic lens with a uniform external shear flow is examined. The study is motivated by the desire to understand the processes that affect Mediterranean Salt Lenses and other mesoscale lenses in the ocean. The first model represents the eddy as a pair of quasigeostrophic 'point potential vortices' in uniform external shear, where the two point vortices are imagined to represent the top and bottom of a baroclinic eddy. While highly idealized, the model succeeds in qualitatively reproducing many aspects of the behavior of more complex models. In the second model the eddy is represented by an isolated three dimensional patch characterized by quasigeostrophic potential vorticity linear in z, in a background flow with constant potential vorticity. The boundary of the lens may be deformed by interactions with a uniform background shear. A family of linearized analytical solutions representing such a vortex is discussed in Chapter 3. These solutions represent lens-like eddies with trapped fluid cores, which may propagate through the surrounding water when there is external vertical shear. The analysis predicts the possible forms of the boundary deformation in a specified external flow, and the precession rate of normal mode boundary perturbations in the absence of external flow. The translation speed of the lens with respect to the surrounding fluid is found to be a simple function of the external vertical shear and the core baroclinicity. A numerical algorithm which is a generalization of the contour dynamics technique to stratified quasigeostrophic flow is used to extend the linear results into the nonlinear regime. This numerical analysis allows a determination of the range of environmental conditions (e.g., the maximum shear and/ or core baroclinicity) in which coherent vortex solutions can be found, and allows the stability of the steadily translating solutions to be examined directly. It is found that the solutions are stable if neither the external shear nor the core baroclinicity is too large, and that the breakdown of the unstable solutions is characterized by the loss of an extrusion of core fluid to the surrounding waters. The translation speeds of the large amplitude numerical solutions are found to have the same functional dependence on the external vertical shear and the core baroclinicity that was found in the linear analysis, and it is demonstrated that the solutions translate at a rate which is equal to the background flow speed at the center of potential vorticity of the lens. As a test of the model results, new data from a recent SOFAR float experiment are presented and compared with the model predictions. The data show that the cores of two different Mediterranean Salt Lenses are tilted, presumably as a result of interactions with external flows. Both the sense of the tilt and its relation to the translation of the lens are in qualitative agreement with the model solutions.
Download or read book Sea Duct written by and published by . This book was released on 1988 with total page 648 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Sea Duct Ocean-Bottom Laboratory is a computer controlled recirculating inverted flume for the in-situ study of sediment transport. It is designed to measure the sea floor response to controlled currents analogous to those generated by surface waves, tidal, or deep ocean storms. The external support frame is an equilateral triangle with sixteen foot sides. It is 12 feet high, has an air weight of 12,500 lbs., and a 2800 lb. submerged weight. Three lead acid battery packs located at the vertex of the triangle legs provide power for the recirculating water pumps, hydraulic power, and ancillary equipment. The inner rotatable structure consists of a 4 foot long by 2 foot wide open bottom windowed test section that is 9 inches high. It is connected to 30 feet of 8 inch tube configured as an elongated toroid. Above the test section is a traverse carriage with stereo camera, flash, and a laser Doppler velocimeter to measure fluid stresses. Internal flow velocities are controlled and can be ramped up to approximately 2 ft/sec providing shear stress sufficient to scour sand, silts, and fine clays. Water and sediment sampling devices obtain specimens from inside and outside the test section.
Download or read book Flow Over Finite Isolated Topography written by LuAnne Thompson and published by . This book was released on 1990 with total page 722 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Data base of Antarctic Pre Pleistocene Sediment Cores written by David Lazarus and published by . This book was released on 1987 with total page 672 pages. Available in PDF, EPUB and Kindle. Book excerpt: A listing of high southern latitude (>30° S) pre-Pleistocene sediment cores is given for samples obtained by the coring and drilling programs of the Lamont-Doherty Geological Observatory, the Antarctic Program of the Florida State University, the French Museum national d'Histoire naturelle, and the Deep Sea Drilling Program. Information on geologic age, core length, lithology, bathymetry, and geographic location are given for each sediment sample. Ages of cores are given whenever possible to the nearest sub-epoch (middle Miocene, etc), together with (when known) the fossils used to determine the age, and the source of the age determination. Many core ages are from previously unpublished sources. The listing provides information on approximately 500 different cores. A computer-searchable version of the database may be obtained by writing to the senior author. A brief analysis of latitudinal and bathymetric patterns of sedimentation is also given for the Paleogene, Miocene, and Pliocene of the Southern Ocean. Throughout the Neogene, an essentially modern pattern of sedimentation is seen, with carbonate ooze predominating north of the present-day position of the polar front, siliceous ooze between the polar front and approximately 65° S, and clay near the Antarctic continent and in water depths>4 km. Paleogene and Cretaceous patterns of sedimentation appear to be different, but are difficult to distinguish due to plate motion and subsidence, and also because of the relatively small number of available pre-Neogene sediment cores.
Download or read book Abstracts of Papers Submitted in for Publication written by and published by . This book was released on 1986 with total page 186 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Efficient Representation of the Hydrographic Structure of the North Atlantic Ocean and Aspects of the Circulation from Objective Methods written by Ichiro Fukumori and published by . This book was released on 1989 with total page 674 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Cities and Their Vital Systems written by Advisory Committee on Technology and Society and published by National Academies Press. This book was released on 1989 with total page 1298 pages. Available in PDF, EPUB and Kindle. Book excerpt: Cities and Their Vital Systems asks basic questions about the longevity, utility, and nature of urban infrastructures; analyzes how they grow, interact, and change; and asks how, when, and at what cost they should be replaced. Among the topics discussed are problems arising from increasing air travel and airport congestion; the adequacy of water supplies and waste treatment; the impact of new technologies on construction; urban real estate values; and the field of "telematics," the combination of computers and telecommunications that makes money machines and national newspapers possible.
Download or read book Government Reports Announcements Index written by and published by . This book was released on 1989-10 with total page 556 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Berichte aus dem Institut f r Meereskunde an der Christian Albrechts Universit t Kiel written by Universität Kiel. Institut für Meereskunde and published by . This book was released on 1994 with total page 472 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Government reports annual index written by and published by . This book was released on 199? with total page 1092 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Exact Reconstruction of Ocean Bottom Velocity Profiles from Monochromatic Scattering Data written by André A. Merab and published by . This book was released on 1988 with total page 712 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis presents the theoretical and computational underpinnings of a novel approach to the determination of the acoustic parameters of the ocean bottom using a monochromatic source. The problem is shown to be equivalent to that of the reconstruction of the potential in a Schrodinger equation from the knowledge of the plane-wave reflection coefficient as a function of vertical wavenumber, r(kz) for all real positive k z. First, the reflection coefficient is shown to decay asymptotically at least as fast as (1/kz2) for large kz and is therefore inteqrable. The Gelfand-Levitan inversion procedure is extended to include the case of basement velocity higher than the velocity of sound in water. The neglect of bound states is shown to be justified in both clayey silt and silty clay at the 220 Hz frequency of operation. Three methods for the numerical solution of the integral equation are investigated. The first one is an "Improved Born approximation" wherein the solution is given as a series expansion the first term of which is the Born approximation while the second term represents a substantial and yet easy to implement improvement over Born. The two other methods are based on a discretization of the Gelfand-Levitan integral equation, and both avoid a matrix inversion: one by employing a recursive procedure, and the other by coupling the Gelfand-Levitan equation with a partial differential equation. Bounds are obtained on errors in the solution due either to discretization or to data inaccuracy. These methods are tested on synthetic data obtained from known geoacoustic models of the ocean bottom. Results are found to be very accurate particularly at the top of the sediment layer with resolution of less than the wavelength of the acoustic source in the water. Several effects are investigated, such as sampling, attenuation, and noise. Also examined is the gradual restriction of the reflection coefficient to a finite range of vertical wave numbers and the consequent progressive deterioration of the reconstruction. The analysis shows how to reconstruct velocity profiles in the presence of density variation when the experiment is conducted at two frequencies. Our results provide a good understanding of the issues involved in conducting a monochromatic deep ocean bottom experiment and constitute a promising technique for processing the experimental data when it becomes available.
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1988 with total page 240 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Government Reports Annual Index Keyword A L written by and published by . This book was released on 1988 with total page 1016 pages. Available in PDF, EPUB and Kindle. Book excerpt:
