Download or read book Analyzing Eddy Transport of Carbon Dioxide in the Southern Ocean Using a High resolution Model written by Mary Elizabeth Woloszyn and published by . This book was released on 2009 with total page 244 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Mesoscale Eddy Transport Across the Antarctic Circumpolar Current written by Audrey-Anne Gauthier and published by . This book was released on 2020 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Interactions of Jets and Eddies with Topography in the Southern Ocean written by Christopher Charles Chapman and published by . This book was released on 2014 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Southern Ocean, which lies south of approximately 35 degrees S and completely encircles the Antarctic continent, is considered to be a unique and important component of the Earth's climate system. The Southern Ocean is home to the world's strongest current system, the Antarctic Circumpolar Current (ACC), which connects the Earth's major ocean basins, mediates the southward transfer of heat, and strongly influences climate on both short and millennial time scales. However, due primarily to lack of observations and insufficient computing power, the dynamics of the Antarctic Circumpolar Current are poorly understood. Modern ocean observing technology and advanced numerical modelling have revealed that the ACC is composed of numerous fine-scale features: strong, narrow currents called "jets" and ring shaped, turbulent features known as "eddies". Although it is widely acknowledged that the nature of the Southern Ocean's flow field has a dramatic influence on the dynamics of the ACC and its interaction with the global climate system, exactly how and why are still questions that perplex oceanographers. The work conducted in this thesis investigates how the fine scale nature of the Southern Ocean flow affects the system as a whole. A particular focus is the interaction of these small scale features with bathymetry. Using a combination of in-situ observations, data collected from satellites and the output of high-resolution numerical models, a newly discovered mode of low-frequency variability, dubbed ̀̀jet--jumping", whereby two jets that pass close to each other near a particular topographic feature show strongly anti-correlated behaviour: one jet strengthening while the other weakens. A dynamical explanation of this behaviour is proposed: variability in the jets arises due to their interaction with a vortex generated through eddy-topography interaction. The predictions of this framework are tested in an idealised numerical model of the Southern Ocean as well as several case studies conducted using sea-surface height altimetry. By adapting methods from signal processing, improvements to an existing method for the detection of jets in the Southern Ocean are proposed. This new method is compared with several existing methods for jet detection, both quantitatively and qualitatively. The new method is found to have superior error performance when compared to with several existing methods. Qualitative comparisons are undertaken using output from an eddy-resolving numerical simulation. It is found that in a global sense, all methods compared are in broad agreement in the placement of jets. However, it is shown that the nature of detected jet field differs depending on the method used. In particular, the new method reveals a finer-scale, more complex jet field than popular contour methods. Finally, the dynamics of s̀̀torm tracks", regions of anomalously high eddy kinetic energy, are explored using a primitive equation model with idealised bottom topography. Using the output of this model, a dynamical mechanism for the formation and downstream development of storm tracks is developed. In this mechanism, it is large scale, topographically forced stationary meanders that initiate the storm track, while eddy-eddy interactions cause the storm track to develop downstream.
Download or read book Ocean Mixing written by Michael Meredith and published by Elsevier. This book was released on 2021-09-16 with total page 386 pages. Available in PDF, EPUB and Kindle. Book excerpt: Ocean Mixing: Drivers, Mechanisms and Impacts presents a broad panorama of one of the most rapidly-developing areas of marine science. It highlights the state-of-the-art concerning knowledge of the causes of ocean mixing, and a perspective on the implications for ocean circulation, climate, biogeochemistry and the marine ecosystem. This edited volume places a particular emphasis on elucidating the key future questions relating to ocean mixing, and emerging ideas and activities to address them, including innovative technology developments and advances in methodology. Ocean Mixing is a key reference for those entering the field, and for those seeking a comprehensive overview of how the key current issues are being addressed and what the priorities for future research are. Each chapter is written by established leaders in ocean mixing research; the volume is thus suitable for those seeking specific detailed information on sub-topics, as well as those seeking a broad synopsis of current understanding. It provides useful ammunition for those pursuing funding for specific future research campaigns, by being an authoritative source concerning key scientific goals in the short, medium and long term. Additionally, the chapters contain bespoke and informative graphics that can be used in teaching and science communication to convey the complex concepts and phenomena in easily accessible ways. - Presents a coherent overview of the state-of-the-art research concerning ocean mixing - Provides an in-depth discussion of how ocean mixing impacts all scales of the planetary system - Includes elucidation of the grand challenges in ocean mixing, and how they might be addressed
Download or read book The Ocean Carbon Cycle and Climate written by Mick Follows and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 401 pages. Available in PDF, EPUB and Kindle. Book excerpt: Our desire to understand the global carbon cycle and its link to the climate system represents a huge challenge. These overarching questions have driven a great deal of scientific endeavour in recent years: What are the basic oceanic mechanisms which control the oceanic carbon reservoirs and the partitioning of carbon between ocean and atmosphere? How do these mechanisms depend on the state of the climate system and how does the carbon cycle feed back on climate? What is the current rate at which fossil fuel carbon dioxide is absorbed by the oceans and how might this change in the future? To begin to answer these questions we must first understand the distribution of carbon in the ocean, its partitioning between different ocean reservoirs (the "solubility" and "biological" pumps of carbon), the mechanisms controlling these reservoirs, and the relationship of the significant physical and biological processes to the physical environment. The recent surveys from the JGOFS and WOCE (Joint Global Ocean Flux Study and World Ocean Circulation Ex periment) programs have given us a first truly global survey of the physical and biogeochemical properties of the ocean. These new, high quality data provide the opportunity to better quantify the present oceans reservoirs of carbon and the changes due to fossil fuel burning. In addition, diverse process studies and time-series observations have clearly revealed the complexity of interactions between nutrient cycles, ecosystems, the carbon-cycle and the physical envi ronment.
Download or read book The Southern Ocean Meridional Overturning Circulation as Diagnosed from an Eddy Permitting State Estimate written by Matthew R. Mazloff and published by . This book was released on 2008 with total page 127 pages. Available in PDF, EPUB and Kindle. Book excerpt: A modern general circulation model of the Southern Ocean with one-sixth of a degree resolution is optimized to the observed ocean in a weighted least squares sense. Convergence to the state estimate solution is carried out by systematically adjusting the control variables (atmospheric state and initial conditions) using the adjoint model. A cost function compares the model state to in situ observations (Argo float profiles, CTD synoptic sections, SEaOS instrument mounted seal profiles, and XBTs), altimetric observations (ENVISAT, GEOSAT, Jason, TOPEX/Poseidon), and other data sets (e.g. infrared and microwave radiometer observed sea surface temperature and NSIDC sea-ice concentration). Costs attributed to control variable perturbations ensure a physically realistic solution. The state estimate is found to be largely consistent with the individual observations, as well as with integrated fluxes inferred from previous static inverse models. The transformed Eulerian mean formulation is an elegant way to theorize about the Southern Ocean. Current researchers utilizing this framework, however, have been making assumptions that render their theories largely irrelevant to the actual ocean. It is shown that theories of the overturning circulation must include the effect of pressure forcing. This is true in the most buoyant waters, where pressure forcing overcomes eddy and wind forcing to balance a poleward geostrophic transport and allows the buoyancy budget to be closed. Pressure forcing is also lowest order at depth. Indeed, the Southern Ocean's characteristic multiple cell overturning is primarily in geostrophic balance. Several other aspects of the Southern Ocean circulation are also investigated in the thesis, including an analysis of the magnitude and variability of heat, salt, and volume inter-basin transports.
Download or read book Ocean Biogeochemistry written by Michael J.R. Fasham and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 324 pages. Available in PDF, EPUB and Kindle. Book excerpt: Oceans account for 50% of the anthropogenic CO2 released into the atmosphere. During the past 15 years an international programme, the Joint Global Ocean Flux Study (JGOFS), has been studying the ocean carbon cycle to quantify and model the biological and physical processes whereby CO2 is pumped from the ocean's surface to the depths of the ocean, where it can remain for hundreds of years. This project is one of the largest multi-disciplinary studies of the oceans ever carried out and this book synthesises the results. It covers all aspects of the topic ranging from air-sea exchange with CO2, the role of physical mixing, the uptake of CO2 by marine algae, the fluxes of carbon and nitrogen through the marine food chain to the subsequent export of carbon to the depths of the ocean. Special emphasis is laid on predicting future climatic change.
Download or read book An Analysis of Results of a High Resolution World Ocean Circulation Model written by Wesley A. Barton and published by . This book was released on 1988 with total page 163 pages. Available in PDF, EPUB and Kindle. Book excerpt: Results of a highly vectorized and multitasked model of the world ocean circulation were analyzed. This model which uses realistic physics, geometry, and forcing on a high-resolution grid, was run on the NCAR Cray X-MP/48 using a robust-diagnostic strategy. Twenty years of model integration using one-half degree horizontal resolution and 20 levels of vertical resolution were accomplished after 200 wall-clock hours at a maximum FORTRAN performance speed of 450 megaflops. Seven key regions of the world ocean were analyzed using an ocean model processor. A representation of the global ocean circulation emerged that compared well with observations and that included strong advective features, fronts, and subtropical meanders. A diagnostic analysis program was developed to analyze meridional heat and volume transports. The results in all basins appear to be reasonable when compared to the results of other studies. For example, an anomalous northward heat transport of 3.8 x 10 to the 14th power W at 30 deg in the South Atlantic compares favorably with the estimate of 4.2 x 10 to the 14th power W at 32 deg S by Bennett (1978) using hydrographic data. The results of simulations conducted in this study can be compared and contrasted against the results of future eddy-resolving simulations. Keywords: Digital simulation, Advection, Heat transport, Meridional volume transport, Oceanographic fronts, Meanders, Thermoclines, Finite difference analysis. Theses. (EDC).
Download or read book Using FRAM to Estimate Eddy Heat Transport in the Southern Ocean written by S. R. Thompson 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 Ocean Biogeochemical Dynamics written by Jorge L. Sarmiento and published by Princeton University Press. This book was released on 2006-06-09 with total page 526 pages. Available in PDF, EPUB and Kindle. Book excerpt: Ocean Biogeochemical Dynamics provides a broad theoretical framework upon which graduate students and upper-level undergraduates can formulate an understanding of the processes that control the mean concentration and distribution of biologically utilized elements and compounds in the ocean. Though it is written as a textbook, it will also be of interest to more advanced scientists as a wide-ranging synthesis of our present understanding of ocean biogeochemical processes. The first two chapters of the book provide an introductory overview of biogeochemical and physical oceanography. The next four chapters concentrate on processes at the air-sea interface, the production of organic matter in the upper ocean, the remineralization of organic matter in the water column, and the processing of organic matter in the sediments. The focus of these chapters is on analyzing the cycles of organic carbon, oxygen, and nutrients. The next three chapters round out the authors' coverage of ocean biogeochemical cycles with discussions of silica, dissolved inorganic carbon and alkalinity, and CaCO3. The final chapter discusses applications of ocean biogeochemistry to our understanding of the role of the ocean carbon cycle in interannual to decadal variability, paleoclimatology, and the anthropogenic carbon budget. The problem sets included at the end of each chapter encourage students to ask critical questions in this exciting new field. While much of the approach is mathematical, the math is at a level that should be accessible to students with a year or two of college level mathematics and/or physics.
Download or read book Antarctic Sea Ice Variability in the Southern Ocean Climate System written by National Academies of Sciences, Engineering, and Medicine and published by National Academies Press. This book was released on 2017-04-24 with total page 83 pages. Available in PDF, EPUB and Kindle. Book excerpt: The sea ice surrounding Antarctica has increased in extent and concentration from the late 1970s, when satellite-based measurements began, until 2015. Although this increasing trend is modest, it is surprising given the overall warming of the global climate and the region. Indeed, climate models, which incorporate our best understanding of the processes affecting the region, generally simulate a decrease in sea ice. Moreover, sea ice in the Arctic has exhibited pronounced declines over the same period, consistent with global climate model simulations. For these reasons, the behavior of Antarctic sea ice has presented a conundrum for global climate change science. The National Academies of Sciences, Engineering, and Medicine held a workshop in January 2016, to bring together scientists with different sets of expertise and perspectives to further explore potential mechanisms driving the evolution of recent Antarctic sea ice variability and to discuss ways to advance understanding of Antarctic sea ice and its relationship to the broader ocean-climate system. This publication summarizes the presentations and discussions from the workshop.
Download or read book Deep Convection and Deep Water Formation in the Oceans written by Simon Chu and published by Elsevier. This book was released on 1991-09-17 with total page 395 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book contains articles presenting current knowledge about the formation and renewal of deep waters in the ocean. These articles were presented at an international workshop at the Naval Postgraduate School in Monterey in March 1990. It is the first book entirely devoted to the topic of deep water formation in which articles have been both selected and reviewed, and it is also the first time authors have addressed both surface and deep mixed layers. Highlighted are: past and recent observations (description and analysis), concepts and models, and modern techniques for future research. Thanks to spectacular advances realised in computing sciences over the last twenty years this volume includes a number of sophisticated numerical models. Observational as well as theoretical studies are presented and a clear distinction is established between open-ocean deep convection and shelf processes, both leading to deep- and bottom-water formation. The main subject addressed is the physical mechanism by which the deep water in the ocean can be renewed. Ventilation occurs at the surface in areas called the gills, where water is mixed and oxygenated before sinking and spreading in the abyss of the deep ocean. This phenomenon is a very active area for both experimentalists and theoreticians because of its strong implications for the understanding of the world ocean circulation and Earth climate. This major theme sheds light on specific and complex processes happening in very restricted areas still controlling three quarters of the total volume of the ocean. All articles include illustrations and a bibliography. This book will be of particular interest to physical oceanographers, earth scientists, environmentalists and climatologists.
Download or read book An Analysis of Eddy Resolving Global Ocean Models in the Southern Ocean written by Rosemarie O'Carroll and published by . This book was released on 1994 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1995 with total page 542 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Parameterizing Southern Ocean Eddy induced Circulation in Coarse Resolution Ocean Models written by and published by . This book was released on 2018 with total page 144 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Numerical Ocean Circulation Modeling written by Dale B. Haidvogel and published by World Scientific Publishing Company. This book was released on 1999 with total page 318 pages. Available in PDF, EPUB and Kindle. Book excerpt: "This book offers a comprehensive overview of the models and methods employed in the rapidly advancing field of numerical ocean circulation modeling. For those new to the field, concise reviews of the equations of oceanic motion, sub-grid-scale parameterization and numerical approximation techniques are presented. The extensive list of references make this book a valuable text for both graduate students and postdoctoral researchers in the marine sciences and in related fields, such as meteorology, climate and coupled biogeochemical modeling."--BOOK JACKET.Title Summary field provided by Blackwell North America, Inc. All Rights Reserved
Download or read book Southern Ocean Mesoscale Eddy Mean Flow Interaction Mixed Layer Dynamics and Their Relationships with the Southern Annular Mode written by Qian Li and published by . This book was released on 2018 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The Antarctic Circumpolar Current (ACC) extends unbroken around the Southern Ocean and is important to the global ocean circulation and Earths climate. The ACC dynamics remains elusive in part because the role of turbulent mesoscale eddies on setting the state of the Southern Ocean remains less certain. In this dissertation, the relationship between the ACC jets and mesoscale eddy fluxes is investigated in the Indo-western Pacific Southern Ocean using an eddy-resolving model simulation. In this region, where the jets are relatively well-defined, the analysis shows that transient eddy momentum fluxes drive the ACC jets. Associated with these ACC jets, there are jet-scale overturning circulations (JSOCs). Analogous to the eddy momentum flux-driven portion of the atmospheric Ferrel Cell, these JSOCs, which are thermally indirect with sinking motions on the equatorward flank of the jet and rising motions on the poleward flank of the jet, are also discernible in transformed Eulerian mean framework and potential density coordinates. Therefore, these JSOCs describe Lagrangian motion. The JSOCs cannot be attributed to Ekman downwelling because the Ekman vertical velocities are much weaker than those of the JSOCs and Ekman meridional structure shares little resemblance to the rapidly varying JSOCs pattern that we observe in the model simulation. Furthermore, for the first time, observational evidence of the existence of JSOCs is demonstrated using Argo float data. The significantly enhanced negative cross-stream motion of the JSOCs across the jet cores is revealed by Argo float trajectories, and the perturbation vertical motion is inferred from Argo salinity fields.The eddy-driven JSOCs have a pronounced impact on the formation of a narrow band of the deep mixed layer (hereinafter mixed layer wedge) in the Indo-western Pacific Southern Ocean. The mixed layer wedge starts to deepen in June, centered at 47.5S, with a meridional scale of only ~2. Its center is located ~1 north of the Subantarctic Front (SAF), the northernmost front of the ACC. This structure is obtained from both the eddy-resolving model simulation and Argo float data. The formation of the mixed layer wedge is found to coincide with destratification underneath the mixed layer. This destratification can be attributed primarily to the descending branch of the JSOC on the warmer, equatorward flank of the SAF, promoting destratification during the warm season. Ekman advection contributes to the formation of the mixed layer, but it occurs farther north of the region where the mixed layer initially deepens. The winter net air-sea heat flux is only a response to the earlier mixed layer. These findings suggest that the eddy-driven JSOC associated with the SAF plays an important role in initiating the narrow and deep mixed layer wedge that forms north of the SAF.The Southern Ocean mixed layer depth (MLD) shows a significant non-zonal variability in response to the Southern Annular Mode (SAM) on seasonal-to-interannual timescales. As the leading mode of atmospheric variability in the Southern Hemisphere extratropics, the SAM is characterized by a zonally symmetric pattern with its positive phase of anomalously low pressure over the polar cap and anomalously high pressure over the mid-latitudes. Following the prominent SAM events that occur in austral summer, MLD anomalies appear in the subsequent austral winters, from June to August. These winter MLD anomalies show two significantly developed regions of Indo-western Pacific and eastern Pacific Southern Oceans, which peak in August in the former and in June in the latter. The complex spatial and temporal MLD anomalies are attributed to mixed-layer potential density anomalies, which are dependent on both potential temperature and salinity anomalies. The analysis indicates that wave-like, rather than zonally symmetric, atmospheric circulation anomalies lead to the potential temperature and salinity anomalies through air-sea fluxes of heat and fresh water, respectively.
