Download or read book Physical model of bathymetric effects on the Antarctic Circumpolar Current written by D.L. BOYER and published by . This book was released on 1993 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Recent Research Advances in the Fluid Mechanics of Turbulent Jets and Plumes written by P.A. Davies and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 513 pages. Available in PDF, EPUB and Kindle. Book excerpt: Challenging problems involvrllg jet and plume phenomena are common to many areas of fundamental and applied scientific research, and an understanding of plume and jet behaviour is essential in many geophysical and industrial contexts. For example, in the field of meteorology, where pollutant dispersal takes place by means of atmospheric jets and plumes formed either naturally under conditions of convectively-driven flow in the atmospheric boundary layer, or anthropogenically by the release of pollutants from tall chimneys. In other fields of geophysics, buoyant plumes and jets are known to play important roles in oceanic mixing processes, both at the relatively large scale (as in deep water formation by convective sinking) and at the relatively small scale (as with plume formation beneath ice leads, for example). In the industrial context, the performances of many engineering systems are determined primarily by the behaviour of buoyant plumes and jets. For example, (i) in sea outfalls, where either sewage or thermal effluents are discharged into marine and/or freshwater environments, (ii) in solar ponds, where buoyant jets are released under density interfaces, (iii) in buildings, where thermally-generated plumes affect the air quality and ventilation properties of architectural environments, (iv) in rotating machinery where fluid jet~ are used for cooling purposes, and (v) in long road and rail tunnels, where safety and ventilation prcedures rely upon an understanding of the behaviour of buoyant jets. In many other engineering and oceanographic contexts, the properties of jets and plumes are of great importance.
Download or read book The South Atlantic written by Gerold Wefer and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 815 pages. Available in PDF, EPUB and Kindle. Book excerpt: The book presents results of recent projects in oceanography and marine geosciences (e.g. WOCE, JGOFS, PAGES, ODP) regarding present and past circulation in the South Atlantic. The objective of the book is to integrate results from both oceanographic and geological studies. As the connecting link between the Antarctic and the North Atlantic, the South Atlantic plays a crucial role with regard to the heat budget of the North Atlantic and to the biogeochemical budget of the global ocean. New results from studies of meridional water mass and heat transports are presented. The central theme of geological investigations is the reconstruction of current and productivity systems in the South Atlantic during the late Quaternary.
Download or read book Dynamics of the Antarctic Circumpolar Current written by Sarah Tragler Gille and published by . This book was released on 1995 with total page 226 pages. Available in PDF, EPUB and Kindle. Book excerpt: Geosat altimeter data and numerical model output are used to examine the circulation and dynamics of the Antarctic Circumpolar Current (ACC). The mean sea surface height across the ACC has been reconstructed from height variability measured by the Geosat altimeter, without assuming prior knowledge of the geoid. For this study, an automated technique has been developed to estimate mean sea surface height for each satellite ground track using a meandering Gaussian jet model, and errors have been estimated using Monte Carlo simulation. The results are objectively mapped to produce a picture of the mean Subantarctic and Polar Fronts, which together comprise the major components of the ACC. The locations of the fronts are consistent with in situ observations and indicate that the fronts are substantially steered by bathymetry. The jets have an average Gaussian width of about 44 km in the meridional direction and meander about 75 km to either side of their mean locations. The width of the fronts is proportional to 1/f, indicating that with constant stratification, the width is proportional to the baroclinic. Rossby radius. The average height difference across the Subantarctic Front (SAF) is 0.7 m and across the Polar Front (PF) 0.6 m. The mean widths of the fronts are correlated with the size of the baroclinic Rossby radius. The meandering jet model explains between 40% and 70% of the height variance along the jet axes. Bathymetric constrictions are associated with increased eddy variability, a smaller percentage of which may be explained by the meandering of the ACC fronts, indicating that propagating eddies and rings may be spawned at topographic features. Detailed examination of spatial and temporal variability in the altimeter data indicates a spatial decorrelation scale of 85 km and a temporal e-folding scale of 34 days. The sea surface height variability is objectively mapped using these scales to define autocovariance functions. The resulting maps indicate substantial evidence of mesoscale eddy activity. Over 17-day time intervals, meanders of the PF and SAF appear to elongate, break off as rings, and propagate. Statistical analysis of ACC variability from altimeter data is conducted using empirical orthogonal functions (EOFs). The first mode EOF describes 16% of the variance in total sea surface height across the ACC; reducing the domain into basin scales does not significantly increase the variance represented by the first EOF, suggesting that the scales of motion are relatively short, and may be determined by local instability mechanisms rather than larger basin scale processes. Likewise, frequency domain EOFs indicate no statistically significant traveling wave modes. The momentum balance of the ACC has been investigated using both output from a high resolution primitive equation model and sea surface height measurements from the Geosat altimeter. In the Semtner-Chervin general circulation model, run with approximately quarter-degree resolution and time varying ECMWF winds, topographic form stress is the dominant process balancing the surface wind forcing. Detailed examination of form stress in the model indicates that it is due to three large topographic obstructions located at Kerguelen Island, Campbell Plateau, and Drake Passage. In order to reduce the effects of standing eddies, the model momentum balance is considered in stream coordinates; vertically integrated through the entire water column, topographic form drag is the dominant balance for wind stress. However, at mid-depth the cross-stream momentum transfer is dominated by horizontal biharmonic friction. In the upper ocean, horizontal friction, mean momentum flux divergence, transient momentum flux divergence, and mean vertical flux divergence all contribute significantly to the momentum balance. Although the relative importance of individual terms in the momentum balance does not vary substantially along streamlines, elevated levels of eddy kinetic energy are associated with the three major topographic features. In contrast, altimeter data show elevated energy levels at many more topographic features of intermediate scales, suggesting that smaller topographic effects are better able to communicate with the surface in the real ocean than in the model. Transient Reynolds stress terms play a small role in the the overall momentum balance; nonetheless, altimeter and model measurements closely agree, and suggest that transient eddies tend to accelerate the mean flow, except in the region between the major fronts which comprise the ACC. Potential vorticity is considered in the model output along Montgomery streamfunction. Even at about 1000 m depth, it varies in response to wind forcing, largely as a result of changes in vertical stratification, indicating that forcing and dissipation do not locally balance in the Southern Ocean. In order to compare model and altimeter potential vorticity estimates, two different proxies for potential vorticity on surface streamlines are considered. Both proxies show very similar results for model and altimeter, suggesting that differences in surface streamlines estimated by the altimeter and the model are not significant in explaining the Southern Ocean flow. The proxies are both roughly conserved along surface height contours but undergo substantial jumps near topographic features. However, they cannot capture stratification changes which may be critically important to the overall potential vorticity balance.
Download or read book Handbook of Environmental Fluid Dynamics Two Volume Set written by Harindra Joseph Fernando and published by CRC Press. This book was released on 2012-12-11 with total page 1197 pages. Available in PDF, EPUB and Kindle. Book excerpt: With major implications for applied physics, engineering, and the natural and social sciences, the rapidly growing area of environmental fluid dynamics focuses on the interactions of human activities, environment, and fluid motion. A landmark for the field, this two-volume handbook presents the basic principles, fundamental flow processes, modeling techniques, and measurement methods used in the field, along with critical discussions of environmental sustainability related to engineering aspects. The first volume provides a comprehensive overview of the fundamentals, and the second volume explores the interactions between engineered structures and natural flows.
Download or read book Ocean Circulation and Climate written by and published by Elsevier. This book was released on 2001-03-27 with total page 737 pages. Available in PDF, EPUB and Kindle. Book excerpt: The book represents all the knowledge we currently have on ocean circulation. It presents an up-to-date summary of the state of the science relating to the role of the oceans in the physical climate system.The book is structured to guide the reader through the wide range of World Ocean Circulation Experiment (WOCE) science in a consistent way. Cross-references between contributors have been added, and the book has a comprehensive index and unified reference list.The book is simple to read, at the undergraduate level. It was written by the best scientists in the world who have collaborated to carry out years of experiments to better understand ocean circulation.
Download or read book Handbook of Environmental Fluid Dynamics Volume One written by Harindra Joseph Fernando and published by CRC Press. This book was released on 2012-12-12 with total page 638 pages. Available in PDF, EPUB and Kindle. Book excerpt: With major implications for applied physics, engineering, and the natural and social sciences, the rapidly growing area of environmental fluid dynamics focuses on the interactions of human activities, environment, and fluid motion. A landmark for the field, the two-volume Handbook of Environmental Fluid Dynamics presents the basic principles, fundamental flow processes, modeling techniques, and measurement methods used in the study of environmental motions. It also offers critical discussions of environmental sustainability related to engineering. The handbook features 81 chapters written by 135 renowned researchers from around the world. Covering environmental, policy, biological, and chemical aspects, it tackles important cross-disciplinary topics such as sustainability, ecology, pollution, micrometeorology, and limnology. Volume One: Overview and Fundamentals provides a comprehensive overview of the basic principles. It starts with general topics that emphasize the relevance of environmental fluid dynamics research in society, public policy, infrastructure, quality of life, security, and the law. It then discusses established and emerging focus areas. The volume also examines the sub-mesoscale flow processes and phenomena that form the building blocks of environmental motions, with emphasis on turbulent motions and their role in heat, momentum, and species transport. As communities face existential challenges posed by climate change, rapid urbanization, and scarcity of water and energy, the study of environmental fluid dynamics becomes increasingly relevant. This volume is a valuable resource for students, researchers, and policymakers working to better understand the fundamentals of environmental motions and how they affect and are influenced by anthropogenic activities. See also Handbook of Environmental Fluid Dynamics, Two-Volume Set and Volume Two: Systems, Pollution, Modeling, and Measurements.
Download or read book Contributions to the Dynamics of the Antarctic Circumpolar Current A C C II written by Takashi Ichiye and published by . This book was released on 1975 with total page 68 pages. Available in PDF, EPUB and Kindle. Book excerpt: Non-dimensional equations of motion are derived for the A.C.C. of the barotropic mode, including the bottom friction and the horizontal eddy viscosity. Integration of the vorticity equation leads to the zeroth order stream function which is dependent only on depth divided by Coriolis' parameter. Integration of the momentum equation along a streamline yields the relation between the momentum input by wind stress and its dissipation by the bottom friction and by the horizontal eddy viscosity. The relation determines the magnitude of the stream function. It also explains differences in the total transport of the A.C.C. obtained by Kamenkovich (1962) and by Bryan and Cox (1972).
Download or read book Journal of Physical Oceanography written by and published by . This book was released on 2002-04 with total page 894 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Oceanic Abstracts written by and published by . This book was released on 1997 with total page 798 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Influence of the Antarctic Circumpolar Current on the Atlantic Meridional Circulation written by David J. Widener and published by . This book was released on 2009 with total page 49 pages. Available in PDF, EPUB and Kindle. Book excerpt: The physics of the Meridional Overturning Circulation and inter-hemispheric heat transport is explored with an emphasis on the upper and central ocean using a general ocean circulation model. The ability of the Antarctic Circumpolar Current, bathymetry, and surface temperature and wind stresses to influence the MOC and inter-hemispheric heat transport is considered. All experiments are based on an idealized model of intermediate complexity with analysis focused on the interplay between the surface heat fluxes, geometry, and the meridional transport of heat and volume. The ACC is found to have an effect comparable in magnitude to that of the mechanical and thermodynamic surface forcing upon meridional circulation and inter-hemispheric heat transport. Basin geometry also plays a comparatively minor role in the inter-hemispheric transports but is essential in creating a realistic ACC by removing some of the momentum imparted by surface wind stresses. The combination of the ACC and asymmetric surface forcing results in values of inter-hemispheric transport which are comparable to actual values. This agreement suggests that previous emphasis on deep overturning in the ocean basins and small-scale mixing as a dominant factor in the driving force behind the MOC's strength and maintenance should be reconsidered, with greater emphasis being placed on studying the roles of the upper and central ocean.
Download or read book Current Antarctic Literature written by and published by . This book was released on 1993 with total page 432 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book International Aerospace Abstracts written by and published by . This book was released on 1999 with total page 1020 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Antarctic Bibliography written by and published by . This book was released on 1994 with total page 558 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Marine Research written by and published by . This book was released on 1973 with total page 1200 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Structure and Variability of the Antarctic Circumpolar Current written by Ėduard Iosifovich Sarukhani︠a︡n and published by . This book was released on 1985 with total page 124 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Antarctic Climate Evolution written by Fabio Florindo and published by Elsevier. This book was released on 2008-10-10 with total page 606 pages. Available in PDF, EPUB and Kindle. Book excerpt: Antarctic Climate Evolution is the first book dedicated to furthering knowledge on the evolution of the world's largest ice sheet over its ~34 million year history. This volume provides the latest information on subjects ranging from terrestrial and marine geology to sedimentology and glacier geophysics. - An overview of Antarctic climate change, analyzing historical, present-day and future developments - Contributions from leading experts and scholars from around the world - Informs and updates climate change scientists and experts in related areas of study
