Mesoscale Ocean Dynamics and Biological Productivity PDF Download

Author: Dennis Joseph McGillicuddy
Publisher:
ISBN:
Category : Marine biology
Languages : en
Pages : 630

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Author: Richard G. Williams
Publisher: Cambridge University Press
ISBN: 1139496778
Category : Science
Languages : en
Pages : 433

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Book Description
This textbook for advanced undergraduate and graduate students presents a multidisciplinary approach to understanding ocean circulation and how it drives and controls marine biogeochemistry and biological productivity at a global scale. Background chapters on ocean physics, chemistry and biology provide students with the tools to examine the range of large-scale physical and dynamic phenomena that control the ocean carbon cycle and its interaction with the atmosphere. Throughout the text observational data is integrated with basic physical theory to address cutting-edge research questions in ocean biogeochemistry. Simple theoretical models, data plots and schematic illustrations summarise key results and connect the physical theory to real observations. Advanced mathematics is provided in boxes and appendices where it can be drawn on to assist with the worked examples and homework exercises available online. Further reading lists for each chapter and a comprehensive glossary provide students and instructors with a complete learning package.

Author: Andrew Spencer Delman
Publisher:
ISBN:
Category :
Languages : en
Pages : 215

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The large-scale climate system is driven by imbalances of the reservoirs of heat contained in the world oceans. The transport and redistribution of this heat is determined in part by nonlinear mesoscale eddies (radii ~50-200 km), as well as by planetary waves whose widths approach the size of mesoscale eddies away from the equator. In this dissertation, new analysis techniques are developed and implemented to assess oceanic phenomena in two regions: mesoscale eddy-mean flow interaction in the Kuroshio Extension (KE) region, and the effects of coastal Kelvin waves and mesoscale eddies in the Indian Ocean south of Java. In the KE region, a jet-following coordinate reference frame is used to quantify the contributions of eddies to the vorticity budget along the KE jet in a strongly eddying ocean general circulation model simulation, the Parallel Ocean Program (POP). The jet reference frame preserves synoptic gradients of the jet that are not accurately represented in multi-year Eulerian means. This analysis found that eddies tend to accelerate the jet just downstream of crests in the topographically-induced meanders, implying an intensification of frontal gradients in these areas. In the Indian Ocean, a method involving projections of harmonic basis functions onto altimetry-derived sea level anomaly (SLA) is used to estimate Kelvin wave activity along the equatorial-coastal waveguide. The resulting Kelvin wave coefficient presents a more accurate representation of Kelvin wave activity than that from raw SLA. Moreover, values of the Kelvin wave coefficient in April-June are a robust predictor of positive Indian Ocean Dipole (pIOD) event development later in the calendar year. Finally, a temperature budget using a strongly eddying POP simulation isolates the specific contributions of mesoscale processes south of Java. It shows that Kelvin waves and local wind forcing both contribute substantially to anomalous cooling during pIOD years, while mesoscale eddies have a modest warming effect. These results suggest that mesoscale processes in the study regions have an important influence on the ocean's structure and can trigger a climate response; use of the new analysis techniques may help quantify the effects of mesoscale eddies and planetary waves elsewhere in the oceans.

Author: Isabella Rosso
Publisher:
ISBN:
Category :
Languages : en
Pages : 0

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The Southern Ocean circulation is dominated by the Antarctic Circumpolar Current (ACC), a quasi-zonal current that encircles Antarctica. Typical features of the ACC are an energetic eddy field and jets that influence both the large scale flow and heat and carbon fluxes and, consequently, impact the climate system. Due to the strong zonal flow and weak stratification of the Southern Ocean, topography steers and influences the ACC. For example, Rossby waves or stationary meanders can be found in the lee of topographic features and the structure of jets and fronts can be modified by topography. ACC dynamics are very complex and understanding these dynamics is crucial, given the Southern Ocean role in the global climate system. The Southern Ocean is an environment where, despite a large nutrient availability, the biological productivity is very low. This biological activity is limited by light irradiance and iron availability. However, there exist several locations in the Southern Ocean where, due to a natural iron fertilisation, phytoplankton blooms can be observed. One such location is the Kerguelen Plateau (KP) region in the south Indian Ocean. Numerous physical mechanisms that drive iron into the euphotic zone of KP waters have been identified. However, in these studies sub-mesoscale dynamics, occurring at horizontal scales of several kilometers, have never been included and their contribution to the iron supply never estimated. These structures have been seen to dramatically trigger an ecosystem response in other parts of the ocean, suggesting that they might represent a significant contribution to Southern Ocean blooms. This thesis is focused on the development and analysis of the first sub-mesoscale-resolving (1/80 resolution) ocean model of the KP area. Resolving sub-mesoscale structures results in an enhancement of vertical velocities and transport, compared to mesoscale-resolving simulations (1/20). Results show that sub-mesoscale fields, such as eddy kinetic energy or vertical velocities, are spatially inhomogeneous. Evidence is presented that this inhomogeneity is strongly related to the topographic features of this region. In particular, it is in part due to internal waves excited by the interaction of the large-scale flow with topography and largely due to an indirect generation by the topography: topography controls mesoscale flows, which in turn generate sub-mesoscale activity. The correlation between mesoscale eddy kinetic energy and strain rate fields with sub-mesoscale vertical velocities suggests a possible new route to parameterise sub-mesoscales in coarser resolution models. The modelled velocity field is used to advect Lagrangian particles. The 1/80 resolution experiments are compared to the 1/20 case, finding that waters reach greater depths at the highest resolution. Built on these Lagrangian experiments is the development of an innovative technique for the study of iron supply, used to contrast the contribution of mesoscales and sub-mesoscales. This technique highlights the sensitivity of iron supply to the horizontal resolution, showing a clear enhancement of iron fluxes (by a factor of 2) at higher resolution. Thus, the vertical motion induced by the sub-mesoscales represents a new process to drive iron into the euphotic waters of the KP region.

Author: Jorge L. Sarmiento
Publisher: Princeton University Press
ISBN: 1400849071
Category : Science
Languages : en
Pages : 527

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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.

Author:
Publisher:
ISBN:
Category : Meteorological satellites
Languages : en
Pages : 296

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Author: Kenneth H. Brink
Publisher: Harvard University Press
ISBN: 9780674017405
Category : Political Science
Languages : en
Pages : 630

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Book Description

Author: Michael J. Follows
Publisher:
ISBN: 9781107086166
Category :
Languages : en
Pages : 434

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Book Description
This textbook for advanced undergraduate and graduate students presents a multidisciplinary approach to understanding ocean circulation and how it drives and controls marine biogeochemistry and biological productivity at a global scale. Background chapters on ocean physics, chemistry and biology provide students with the tools to examine the range of large-scale physical and dynamic phenomena that control the ocean carbon cycle and its interaction with the atmosphere. Throughout the text observational data is integrated with basic physical theory to address cutting-edge research questions in o.

Author: David Anthony Griffin
Publisher:
ISBN:
Category : Ocean currents
Languages : en
Pages : 212

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Author: Xinfeng Liang
Publisher:
ISBN:
Category :
Languages : en
Pages :

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This is particularly important for dispersal of larvae and geochemical tracers associated with hydrothermal sources that are found primarily along the crest of mid-ocean ridges. Also, the observed eddy-modulated mixing is expected to be useful for validating and improving numerical-model parameterizations of turbulence and mixing in the ocean. Furthermore, since the frequency and intensity of mesoscale eddies depend on the state of the climate, the observed eddy modulation of deep ocean mixing connects climate change and climate variability to physical and biogeochemical dynamics in the deep ocean and implies an unexplored feedback mechanism potentially affecting the global climate system.