Sea Ice Mechanics Research Progress

Sea Ice Mechanics Research Progress PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 0

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Book Description
The architecture for a new large scale (5 to 100 km, 1 hour to 1 day) sea ice dynamics model based on an anisotropic constitutive law is presented here. This architecture accounts directly for refrozen lead systems in the pack ice strength (with an anisotropic failure surface) and in the ice thickness distribution (with an oriented thickness distribution). The lower limit (5 km) of the model resolution is controlled by the fracture spacing of old, thicker ice and the maximum lead width. The upper limit of the model resolution (100 km) is controlled by curvature in the lead directions and variations in the lead width. These in turn are controlled by the variations in internal ice stress due to driving forces (winds and currents), which set the time resolution. This architecture features abrupt changes in the failure surface and the associated flow rule that cannot be averaged over a time step. In addition, the principal stress normal to a new lead must be zero as it opens. This model has sub-scale simulations that allow for the inclusion of phenomena such as ridging, rafting, buckling, and fracture on the behavior of the ice. With this new ice constitutive law, it is possible to directly test the ice failure strength, plastic flow rule, and ice thickness distribution. The data most useful for this testing come from ice stress and position buoys together with SAR deformation data. Some data comparisons have already been made.

Sea Ice Mechanics Research Progress

Sea Ice Mechanics Research Progress PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 0

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Book Description
The architecture for a new large scale (5 to 100 km, 1 hour to 1 day) sea ice dynamics model based on an anisotropic constitutive law is presented here. This architecture accounts directly for refrozen lead systems in the pack ice strength (with an anisotropic failure surface) and in the ice thickness distribution (with an oriented thickness distribution). The lower limit (5 km) of the model resolution is controlled by the fracture spacing of old, thicker ice and the maximum lead width. The upper limit of the model resolution (100 km) is controlled by curvature in the lead directions and variations in the lead width. These in turn are controlled by the variations in internal ice stress due to driving forces (winds and currents), which set the time resolution. This architecture features abrupt changes in the failure surface and the associated flow rule that cannot be averaged over a time step. In addition, the principal stress normal to a new lead must be zero as it opens. This model has sub-scale simulations that allow for the inclusion of phenomena such as ridging, rafting, buckling, and fracture on the behavior of the ice. With this new ice constitutive law, it is possible to directly test the ice failure strength, plastic flow rule, and ice thickness distribution. The data most useful for this testing come from ice stress and position buoys together with SAR deformation data. Some data comparisons have already been made.

Recent Progress in Snow and Ice Research

Recent Progress in Snow and Ice Research PDF Author: Jacqueline A. Richter-Menge
Publisher:
ISBN:
Category : Ice
Languages : en
Pages : 9

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Book Description
Snow and ice research during the past quadrennial covers a wide range of topics varying from the climatic effects of large ice sheets and sea ice covers to applied problems such as the icing of power lines and communication facilities. This review focuses in more detail on three topics of the many subjects investigated to provide a more coherent look at the advances achieved and prospects for the future. These are: the influences of layers in seasonal snow covers; research in ice mechanics on freshwater and sea ice; and remote sensing of polar ice sheets. These topics provide useful examples of the general needs in snow and ice research applicable to most areas, e.g. better representation in models of detailed processes, careful controlled laboratory experiments to quantify processes, and field studies to provide the appropriate context for interpretation of processes from remote sensing.

Sea Ice Dynamics Project

Sea Ice Dynamics Project PDF Author: J. F. Lane
Publisher:
ISBN:
Category : Sea ice
Languages : en
Pages : 13

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Book Description


Research in Sea Ice Mechanics

Research in Sea Ice Mechanics PDF Author: National Research Council (U.S.). Panel on Sea Ice Mechanics
Publisher:
ISBN:
Category : Ice mechanics
Languages : en
Pages : 96

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Book Description
Panel appointed in 1979 to investigate available information and research needs in field of sea ice mechanics, referring especially to engineering activities in and under ice of polar oceans.

Research in Sea Ice Mechanics

Research in Sea Ice Mechanics PDF Author: National Research Council (U.S.). Assembly of Engineering
Publisher:
ISBN:
Category :
Languages : en
Pages : 80

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Book Description


Sea Ice

Sea Ice PDF Author: David N. Thomas
Publisher: John Wiley & Sons
ISBN: 0470756926
Category : Technology & Engineering
Languages : en
Pages : 419

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Book Description
Sea ice, which covers up to 7% of the planet’s surface, is a major component of the world’s oceans, partly driving ocean circulation and global climate patterns. It provides a habitat for a rich diversity of marine organisms, and is an extremely valuable source of information in studies of global climate change and the evolution of present day life forms. Increasingly sea ice is being used as a proxy for extraterrestrial ice covered systems. Sea Ice provides a comprehensive review of our current available knowledge of polar pack ice, the study of which is severely constrained by the logistic difficulties of working in such harsh and remote regions of the earth. The book’s editors, Drs Thomas and Dieckmann have drawn together an impressive group of international contributing authors, providing a well-edited and integrated volume, which will stand for many years as the standard work on the subject. Contents of the book include details of the growth, microstructure and properties of sea ice, large-scale variations in thickness and characteristics, its primary production, micro-and macrobiology, sea ice as a habitat for birds and mammals, sea ice biogeochemistry, particulate flux, and the distribution and significance of palaeo sea ice. Sea Ice is an essential purchase for oceanographers and marine scientists, environmental scientists, biologists, geochemists and geologists. All those involved in the study of global climate change will find this book to contain a wealth of important information. All libraries in universities and research establishments where these subjects are studied and taught will need multiple copies on their shelves. David Thomas is at the School of Ocean Sciences, University of Wales, Bangor, UK. Gerhard Dieckmann is at the Alfred Wegener Institute for Polar and Marine Research, Bremerhaven, Germany

Physics and Mechanics of Ice

Physics and Mechanics of Ice PDF Author: P. Tryde
Publisher: Springer Science & Business Media
ISBN: 3642814344
Category : Science
Languages : en
Pages : 392

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Book Description
In the programme of the symposium was written: "The International Union of Theoretical and Applied Me chanics has taken the initiative to organize the sympo sium. As the name of IUTAM implies, the organization brings forward achievements within the field of theore tical mechanics for application in science and engineer ing. According to the rules of IUTAM that only invited persons can attend, all lecturers and participants have been ap pOinted by the members of the scientific committee. To facilitate contact among the attending persons, it has been decided to restrict the total number to 85 persons including the lecturers. Only one session is planned, making it possible for everybody to attend all lectures. Most scientists and engineers have realized that the knowledge attained by extensive basic research is essen tial in order to solve technological problems. In the process of acquiring this knowledge we often fail to un derstand that scientific progress is only achieved by two main principles: (1) By studying the scientific litera ture and applying or improving the theories in order to predict behaviour and forces correctly, or (2) by re jecting existing theories and developing new ways to cope with the problem, resulting in a more differenti ated and, hopefully, more exact theory. Ice seems to be a simple material, but it is in fact so complex and strange that it is only in the latest dec ades that we have come to know some of the natural laws governing its behaviour.

Drift, Deformation, and Fracture of Sea Ice

Drift, Deformation, and Fracture of Sea Ice PDF Author: Jerome Weiss
Publisher: Springer Science & Business Media
ISBN: 940076202X
Category : Science
Languages : en
Pages : 95

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Book Description
Sea ice is a major component of polar environments, especially in the Arctic where it covers the entire Arctic Ocean throughout most of the year. However, in the context of climate change, the Arctic sea ice cover has been declining significantly over the last decades, either in terms of its concentration or thickness. The sea ice cover evolution and climate change are strongly coupled through the albedo positive feedback, thus possibly explaining the Arctic amplification of climate warming. In addition to thermodynamics, sea ice kinematics (drift, deformation) appears as an essential factor in the evolution of the ice cover through a reduction of the average ice age (and consequently of the cover's thickness), or ice export out of the Arctic. This is a first motivation for a better understanding of the kinematical and mechanical processes of sea ice. A more upstream, theoretical motivation is a better understanding of the brittle deformation of geophysical objects across a wide range of scales. Indeed, owing to its very strong kinematics, compared e.g. to the Earth’s crust, an unrivaled kinematical data set is available for sea ice from in situ (e.g. drifting buoys) or satellite observations. Here, we review the recent advances in the understanding of sea ice drift, deformation and fracturing obtained from these data. We focus particularly on the scaling properties in time and scale that characterize these processes, and we emphasize the analogies that can be drawn from the deformation of the Earth’s crust. These scaling properties, which are the signature of long-range elastic interactions within the cover, constrain future developments in the modeling of sea ice mechanics. We also show that kinematical and rheological variables such as average velocity, average strain-rate or strength have significantly changed over the last decades, accompanying and actually accelerating the Arctic sea ice decline.

Sea Ice Mechanics Research

Sea Ice Mechanics Research PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 147

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Book Description
The Sea Ice Mechanics and Arctic Workshop was held in Anchorage, Alaska, April 25-28, 1995. The workshop focused on current state of the practice and future research needs relative to offshore oil and gas facilities, and also reviewed the results of the U.S. Navy's Office of Naval Research (ONR) Sea Ice Mechanics Initiative (SIMI). SIMI was an Office of Naval Research Accelerated Research Initiative (ARI), spanning the years 1991 to 1996. Its goals were to: understand sea ice constitutive laws and fracture mechanics over the full range of geophysical scales; and determine the scaled response to applied external forces and develop physically based constitutive and fracture models.

IUTAM Symposium on Physics and Mechanics of Sea Ice

IUTAM Symposium on Physics and Mechanics of Sea Ice PDF Author: Jukka Tuhkuri
Publisher: Springer Nature
ISBN: 3030804399
Category : Technology & Engineering
Languages : en
Pages : 333

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Book Description
This book presents the results of the IUTAM Symposium on Physics and Mechanics of Sea Ice which brought together researchers who have made significant contributions in the study of sea ice. The topics include: Fracture of ice, Thermodynamics of sea ice ridges, Global and local ice loads on ships and marine structures, Computational ice engineering and ice mechanics; and Physical and engineering problems related to ice and waves.