Download or read book Sensitivity of the Ocean s Climate to Diapycnal Diffusivity in an EMIC written by Fabio Dalan and published by . This book was released on 2005 with total page 37 pages. Available in PDF, EPUB and Kindle. Book excerpt: (cont.) Surface warming, induced by enhanced CO2 in the atmosphere, leads to a reduction of the isopycnal slope which translates into a reduction of the above fluxes. The amount of reduction is directly related to the magnitude of the isopycnal diffusive flux and GM advective flux at equilibrium. These latter fluxes depend on the thickness of the thermocline at equilibrium, hence on the diapycnal diffusion. Thus, the increase of deep-ocean heat uptake with diapycnal diffusivity is an indirect effect that the latter parameter has on the isopycnal diffusion and GM advection.
Download or read book Sensitivity of Climate to Diapycnal Diffusivity in the Ocean written by Fabio Dalan and published by . This book was released on 2004 with total page 46 pages. Available in PDF, EPUB and Kindle. Book excerpt: (Cont.) Thus larger diapycnal diffusion is compensated for by changes in isopycnal diffusion and GM advection. Little change is found for the advective flux because of compensation between downward and upward advection. We present sensitivity results for the hysteresis curve of the thermohaline circulation. The stability of the climate system to slow freshwater perturbations is reduced as a consequence of a smaller diapycnal diffusivity. This result confirms the findings of 2-dimensional climate models. However, contrary to the results of these studies, a common threshold for the shutdown of the thermohaline circulation is not found in our model. Part II: The sensitivity of the transient climate to the diapycnal diffusivity in the ocean is studied for a global warming scenario in which CO2 increases by 1% per year for 75 years. The thermohaline circulation slows down for about 100 years and recovers afterward, for any value of the diapycnal diffusivity. The rates of slowdown and of recovery, as well as the percentage recovery of the circulation at the end of 1000-year integrations, are variable but a direct relation with the diapycnal diffusivity cannot be found ...
Download or read book Sensitivity of Climate Change to Diapycnal Diffusivity in the Ocean written by Fabio Dalan and published by . This book was released on 2003 with total page 192 pages. Available in PDF, EPUB and Kindle. Book excerpt: The diapycnal diffusivity of the ocean is one of the least known parameters in cur- rent climate models. Measurements of this diffusivity are sparse and insufficient for compiling a global map. Inferences from inverse methods and energy budget calculations suggests as much as a factor of 5 difference in the global mean value of the diapycnal diffusivity. Yet, the climate is extremely sensitive to the diapycnal diffusivity, as shown by studies using single-hemispheric ocean General Circulation Models (GCMs) and 2-dimensional coupled models. In this thesis we study the sensitivity of both the current climate and the climate change to the diapycnal diffusivity - using, for the first time, a coupled model with a 3-dimensional global ocean component and idealized geometry. Our results show that, at equilibrium, the strength of the thermohaline circulation in the North Atlantic scales with the 0.44 power of the diapycnal diffusivity, in contrast to the theoretical value of 2/3. On the other hand, the strength of the circulation in the South Pacific scales with the 0.63 power of the diapycnal diffusivity. The implication is that the amount of water upwelling from the deep ocean may be regulated by the diapycnal diffusion in the Indo-Pacific ocean. The vertical heat balance in the ocean is controlled by: in the downward direction, (i) advection and (ii) diapycnal diffusion; in the upward direction, (iii) isopycnal diffusion and (iv) bolus velocity (GM) advection. The size of the latter three fluxes increases with diapycnal diffusivity.
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 Ocean Circulation written by Andreas Schmittner and published by John Wiley & Sons. This book was released on 2013-05-02 with total page 752 pages. Available in PDF, EPUB and Kindle. Book excerpt: Published by the American Geophysical Union as part of the Geophysical Monograph Series, Volume 173. The ocean's meridional overturning circulation (MOC) is a key factor in climate change. The Atlantic MOC, in particular, is believed to play an active role in the regional and global climate variability. It is associated with the recent debate on rapid climate change, the Atlantic Multi-Decadal Oscillation (AMO), global warming, and Atlantic hurricanes. This is the first book to deal with all aspects of the ocean's large-scale meridional overturning circulation, and is a coherent presentation, from a mechanistic point of view, of our current understanding of paleo, present-day, and future variability and change. It presents the current state of the science by bringing together the world's leading experts in physical, chemical, and biological oceanography, marine geology, geochemistry, paleoceanography, and climate modeling. A mix of overview and research papers makes this volume suitable not only for experts in the field, but also for students and anyone interested in climate change and the oceans.
Download or read book Sensitivities of Deep ocean Heat Uptake and Heat Content to Surface Fluxes and Subgrid scale Parameters in an Ocean GCM with Idealized Geometry written by Boyin Huang and published by . This book was released on 2002 with total page 43 pages. Available in PDF, EPUB and Kindle. Book excerpt: Sensitivities of the net heat flux into the deep-ocean (Qnet) and of the deep-ocean heat content (DOC) below 700 m are studied using an ocean general circulation model and its adjoint. Both are found to have very similar sensitivities. The sensitivity to the surface freshwater flux (E-P-R) is positive in the Atlantic, but negative in the Pacific and Southern Ocean. A positive sensitivity to the downward net surface heat flux is found only in the North Atlantic north of 40ʻN and the Southern Ocean. The diapycnal diffusivity of temperature affects Qnet and DOC positively in a large area of the tropics and subtropics in both the Pacific and Atlantic Ocean. The isopycnal diffusivity contributes to Qnet and DOC mainly in the Southern Ocean. Detailed analysis indicates that the surface freshwater flux affects Qnet and DOC by changing vertical velocity, temperature stratification, and overturning circulation. The downward net surface heat flux appears to increase Qnet and DOC by strengthening vertical advection and isopycnal mixing. The contribution of isopycnal diffusivity to Qnet and DOC is largely associated with the vertical heat flux due to isopycnal mixing. Similarly, the diapycnal diffusivity of temperature modulates Qnet and DOC through the downward heat flux due to diapycnal diffusion. The uncertainties of Qnet and DOC are estimated based on the sensitivities and error bars of observed surface forcing and oceanic diffusivities. For DOC, they are about 0.7°K (1°K = 3 x 1024 J) for the isopycnal diffusivity, 0.4°K for the diapycnal diffusivity of temperature, 0.3°K for the surface freshwater flux, and 0.1°K for the net surface heat flux and zonal wind stress. Our results suggest that the heat uptake by ocean GCMs in climate experiments is sensitive to the isopycnal diffusivity as well to the diapycnal thermal diffusivity.
Download or read book Sensitivities of Deep ocean Heat Uptake and Heat Content in an OGM with Idealized Geometry written by Boyin Huang and published by . This book was released on 2003 with total page 18 pages. Available in PDF, EPUB and Kindle. Book excerpt: (Cont.) The uncertainties of Qnet and DOC are estimated based on the sensitivities and error bars of observed surface forcing and oceanic diffusivities. For DOC, they are about 0.7°K (1°K = 3 x 1024J) for the isopycnal diffusivity, 0.4°K for the diapycnal diffusivity of temperature, 0.3°K for the surface freshwater flux, and 0.1°K for the net surface heat flux and zonal wind stress. Our results suggest that the heat uptake by ocean GCMs in climate experiments is sensitive to the isopycnal diffusivity as well to the diapycnal thermal diffusivity.
Download or read book Russian Journal of Mathematical Physics written by and published by . This book was released on 2007 with total page 546 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Sensitivity of Ocean Circulation and Climate to Ocean Mixing Parameters and CO2 Forcing in an EMIC with Two Different Atmospheric Representations written by William Griffiths and published by . This book was released on 2014 with total page 76 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Ocean Circulation and Climate written by Jennifer MacKinnon and published by Elsevier Inc. Chapters. This book was released on 2013-10-22 with total page 62 pages. Available in PDF, EPUB and Kindle. Book excerpt: Diapycnal mixing in the ocean interior is driven by a wide range of processes, each with distinct governing physics and unique global geography. Here we review the primary processes responsible for turbulent mixing in the ocean interior, with an emphasis on active work from the past decade. We conclude with a discussion of global patterns of mixing and their importance for regional and large-scale modeling accuracy.
Download or read book Heaving Stretching and Spicing Modes written by Rui Xin Huang and published by . This book was released on 2020 with total page 391 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is focused on fundamental aspects of climate variability in the ocean, in particular changes of the wind-driven circulation. The vertical movement of isopycnal (isothermal) layers, including their stretching and compression, is called heaving and stretching. A major part of climate variability in the ocean is heaving in nature. Heave is primarily associated with the adiabatic motions of isopycnal layers due to change of wind stress. It is rather difficult to separate the contributions from adiabatic and diabatic processes. Isopycnal analysis has been widely used in climate study; however, it is much more accurate to study the isopycnal layers. Here climate signals are examined in terms of changes of layer depth, layer thickness, layer temperature/salinity, spicity and others. In addition to the traditional Theta-S diagram, the sigma-pi (potential density -- potential spicity) diagram can also be used in analyzing water mass property distribution and climate variability. In fact, a radius of signal can be defined rigorously for signals in the sigma-pi diagram; the combination of isopycnal analysis and evaluation of radius of signal provides a powerful tool in analyzing climate variability in the world oceans.
Download or read book Driving the Ocean s Overturning written by Véronique Bugnion and published by . This book was released on 2001 with total page 193 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Diapycnal Mixing in the Ocean written by Ali Mashayek and published by . This book was released on 2013 with total page 438 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Ocean Processes in Climate Dynamics written by P.M. Malanotte-Rizzoli and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 449 pages. Available in PDF, EPUB and Kindle. Book excerpt: One of the most crucial but still very poorly understood topics of oceanographic science is the role of ocean processes in contributing to the dynamics of climate and global change. This book presents a series of high level lectures on the major categories of ocean/atmosphere processes. Three of these major issues are the focus of the lectures: (1) air--sea interaction processes; (2) water mass formation, dispersion and mixing; (3) general circulation, with specific emphasis on the thermohaline component. Global examples in the world ocean are provided and discussed in the lectures. In parallel, the Mediterranean Sea is a laboratory basin in providing analogues of the above global processes relevant to climate dynamics. They include the Mediterranean thermohaline circulation with its own `conveyor belt'; intermediate and deep water mass formation and transformations, dispersion and mixing. No other book in the field provides a review of fundamental lectures on these processes, coupled with global examples and their Mediterranean analogues.
Download or read book Geospatial Modeling for Environmental Management written by Shruti Kanga and published by CRC Press. This book was released on 2022-02-16 with total page 390 pages. Available in PDF, EPUB and Kindle. Book excerpt: This is a comprehensive resource that integrates the application of innovative remote sensing techniques and geospatial tools in modeling Earth systems for environmental management beyond customary digitization and mapping practices. It identifies the most suitable approaches for a specific environmental problem, emphasizes the importance of physically based modeling, their uncertainty analysis, advantages, and disadvantages. The case studies on the Himalayas with a complex topography call for innovation in geospatial techniques to find solutions for various environmental problems. Features: Presents innovative geospatial methods in environmental modeling of Earth systems. Includes case studies from South Asia and discusses different processes and outcomes using spatially explicit models. Explains contemporary environmental problems through the analysis of various information layers. Provides good practices for developing countries to help manage environmental issues using low-cost geospatial approaches. Integrates geospatial modeling with policy and analysis its direct implication in decision making. Using a systems’ approach analysis, Geospatial Modeling for Environmental Management: Case Studies from South Asia shall serve environmental managers, students, researchers, and policymakers.
Download or read book Climate System Modeling written by Kevin E. Trenberth and published by Cambridge University Press. This book was released on 1992 with total page 822 pages. Available in PDF, EPUB and Kindle. Book excerpt: Climate Systems Modeling presents an interdisciplinary and comprehensive study of the dynamics of the whole global system. As a comprehensive text it will appeal to students and researchers concerned with any aspect of climatology and the study of related topics in the broad earth and environmental sciences.
