About the Relevance of Snow Microstructure Study in Cryospheric Sciences PDF Download

Author: Maurine Montagnat
Publisher: Frontiers Media SA
ISBN: 2889663590
Category : Science
Languages : en
Pages : 135

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Author: Marco Tedesco
Publisher: John Wiley & Sons
ISBN: 1118368851
Category : Technology & Engineering
Languages : en
Pages : 430

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Book Description
The cryosphere, that region of the world where water is temporarily or permanently frozen, plays a crucial role on our planet. Recent developments in remote sensing techniques, and the acquisition of new data sets, have resulted in significant advances in our understanding of all components of the cryosphere and its processes. This book, based on contributions from 40 leading experts, offers a comprehensive and authoritative overview of the methods, techniques and recent advances in applications of remote sensing of the cryosphere. Examples of the topics covered include: • snow extent, depth, grain-size and impurities • surface and subsurface melting • glaciers • accumulation over the Greenland and Antarctica ice sheets • ice thickness and velocities • gravimetric measurements from space • sea, lake and river ice • frozen ground and permafrost • fieldwork activities • recent and future cryosphere-oriented missions and experiments All figures are in color and provide an excellent visual accompaniment to the technical and scientific aspect of the book. Readership: Senior undergraduates, Masters and PhD Students, PostDocs and Researchers in cryosphere science and remote sensing. Remote Sensing of the Cryosphere is the significant first volume in the new Cryosphere Science Series. This new series comprises volumes that are at the cutting edge of new research, or provide focussed interdisciplinary reviews of key aspects of the science.

Author: Daniel August Miller
Publisher:
ISBN: 9781423510499
Category : Depth hoar
Languages : en
Pages : 261

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Book Description
Snow microstructure significantly influences the mechanical, thermal, and electromagnetic properties of snow. The microstructure is constantly evolving from the time it is deposited on the surface until it sublimates or melts. The resulting time variant material properties make the study of snow metamorphism of fundamental importance to a wide variety of snow science disciplines. Dry snow metamorphism has traditionally been classified by the thermal gradient encountered in the snowpack. Snow experiencing a predominantly equi-temperature environment develops different micro structure than snow that is subjected to a temperature gradient. As such, previous research has evaluated snow metamorphism based upon select thermal gradient dependent processes, when in reality, there is a continuum of physical processes simultaneously contributing to metamorphism. In previous research, a discrete temperature gradient transition between the two thermal environments has been used to activate separate morphological analyses. The current research focuses on a unifying approach to dry snow metamorphism that is applicable to generalized thermal environments. The movement of heat and mass is not prescribed, but is allowed to develop naturally through modeling of physical processes. Heat conduction, mass conservation, and phase change equations are derived in a simplified two-dimensional approach. Each differential equation is non-linearly coupled to the others through phase change. The microstructural network is then discretized into elements and nodes. Finite difference equations are developed for the network, and numerically solved using iterative techniques. The finite difference model provides a unique platform to study the influence of numerous geometric and thermodynamic parameters relating to dry snow metamorphism. Numerical metamorphism studies in an equi-temperature environment agree well with established trends and published experimental results.

Author: Alden Claire Adolph
Publisher:
ISBN:
Category :
Languages : en
Pages : 266

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Book Description
Snow, ice, and firn (snow more than one year old) have many roles within the environmental system, and our understanding of their physical structures can help to answer a myriad of important open questions in cryospheric sciences. To investigate past climate, scientists study natural archives of atmospheric composition and temperature found in the polar ice sheets. Firn is the porous material on the top 50-120 meters of these ice sheets, and movement of atmospheric gases in firn plays an important role the formation of ice core climate records. In this work, we develop and implement an improved technique to measure firn gas diffusivity. Through laboratory measurements, we determine that gas transport parameters of diffusivity and permeability are sensitive to variability in firn microstructure that density alone cannot describe. As a highly reflective material, snow serves as an important control on global surface energy balance and plays a critical role in the dynamic climate system due to the snow albedo temperature feedback. Increased monitoring and understanding of snow albedo (or reflectivity) and snow temperature is imperative for improved future climate modeling. Through field-based observations in New Hampshire, we determine that snow grain size, and not impurity content, is the main driver of changes in snow albedo in this region. We use these extensive field observations to evaluate a physically-based snow albedo model that is embedded in major climate models, and we show that the model largely overestimates albedo throughout the winter season. In a ground validation experiment of satellite remote sensing snow temperatures in Greenland, we show that agreement between ground-based and satellite-based infrared temperatures is better than previous literature indicates. Throughout this thesis, we use direct measurements of physical properties of snow and firn to generate greater understanding of past, present, and future climate.

Author: H. G. Jones
Publisher: Cambridge University Press
ISBN: 9780521188890
Category : Science
Languages : en
Pages : 0

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Book Description
In this volume, a multidisciplinary group of acknowledged experts fully intergrate the physical, chemical, and biological sciences to provide a complete understanding of the interrelationships between snow structure and life. This volume opens a new perspecitve on snow cover as a habitat for organisms under extreme environmental conditions and as a key factor in the ecology of much of the Earth's surface. The contributors describe the fundamental physical and small-scale chemical processes that characterize the evolution of snow and their influence on the life cycles of true snow organisms and the biota of cold regions with extended snow cover. The book further expands on the role of snow in the biosphere by the study of the relationship between snow and climate and the paleo-ecological evidence for the influence of past snow regimes on plant communities. Snow Ecology will form a main textbook on advanced courses in biology, ecology, geography, environmental science, and earth science where an important component is devoted to the study of the cryosphere. It will also be useful as a reference text for graduate students, researchers, and professionals at academic institutions and in government and nongovernmental agencies with environmental concerns.

Author: H. S. Santeford
Publisher: National Academies
ISBN:
Category : Science
Languages : en
Pages : 816

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Author: Emanuele Santi
Publisher: MDPI
ISBN: 3038978205
Category : Technology & Engineering
Languages : en
Pages : 224

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Book Description
Past research has comprehensively assessed the capabilities of satellite sensors operating at microwave frequencies, both active (SAR, scatterometers) and passive (radiometers), for the remote sensing of Earth’s surface. Besides brightness temperature and backscattering coefficient, microwave indices, defined as a combination of data collected at different frequencies and polarizations, revealed a good sensitivity to hydrological cycle parameters such as surface soil moisture, vegetation water content, and snow depth and its water equivalent. The differences between microwave backscattering and emission at more frequencies and polarizations have been well established in relation to these parameters, enabling operational retrieval algorithms based on microwave indices to be developed. This Special Issue aims at providing an overview of microwave signal capabilities in estimating the main land parameters of the hydrological cycle, e.g., soil moisture, vegetation water content, and snow water equivalent, on both local and global scales, with a particular focus on the applications of microwave indices.

Author: Roger G. Barry
Publisher: Cambridge University Press
ISBN: 1108806708
Category : Science
Languages : en
Pages : 624

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Book Description
Recent studies indicate that - due to climate change - the Earth is undergoing rapid changes in all cryospheric components, including polar sea ice shrinkage, mountain glacier recession, thawing permafrost, and diminishing snow cover. This book provides a comprehensive summary of all components of the Earth's cryosphere, reviewing their history, physical and chemical characteristics, geographical distributions, and projected future states. This new edition has been completely updated throughout, and provides state-of-the-art data from GlobSnow-2 CRYOSAT, ICESAT, and GRACE. It includes a comprehensive summary of cryospheric changes in land ice, permafrost, freshwater ice, sea ice, and ice sheets. It discusses the models developed to understand cryosphere processes and predict future changes, including those based on remote sensing, field campaigns, and long-term ground observations. Boasting an extensive bibliography, over 120 figures, and end-of-chapter review questions, it is an ideal resource for students and researchers of the cryosphere.

Author: W. Tad Pfeffer
Publisher: Frontiers Media SA
ISBN: 2889456196
Category :
Languages : en
Pages : 160

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Book Description
Melt takes place where the surface of glaciers or ice sheets interacts with the atmosphere. While the processes governing surface melt are fairly well understood, the pathways of the meltwater, from its origin to the moment it leaves a glacier system, remain enigmatic. It is not even guaranteed that meltwater leaves a glacier or ice sheet. On Greenland, for example, only slightly more than 50% of the meltwater runs off. The remainder mostly refreezes within the so-called firn cover of the ice sheet. This eBook contains 11 studies which tackle the challenge of understanding meltwater retention in snow and firn from various angles. The studies focus both on mountain glaciers and on the Greenland ice sheet and address challenges such as measuring firn properties, quantifying their influence on meltwater retention, modelling firn processes and meltwater refreezing as well as unravelling the mechanisms within the recently discovered Greenland firn aquifers.

Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 261

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Book Description
Snow microstructure significantly influences the mechanical, thermal, and electromagnetic properties of snow. The microstructure is constantly evolving from the time it is deposited on the surface until it sublimates or melts. The resulting time variant material properties make the study of snow metamorphism of fundamental importance to a wide variety of snow science disciplines. Dry snow metamorphism has traditionally been classified by the thermal gradient encountered in the snowpack. Snow experiencing a predominantly equi-temperature environment develops different micro structure than snow that is subjected to a temperature gradient. As such, previous research has evaluated snow metamorphism based upon select thermal gradient dependent processes, when in reality, there is a continuum of physical processes simultaneously contributing to metamorphism. In previous research, a discrete temperature gradient transition between the two thermal environments has been used to activate separate morphological analyses. The current research focuses on a unifying approach to dry snow metamorphism that is applicable to generalized thermal environments. The movement of heat and mass is not prescribed, but is allowed to develop naturally through modeling of physical processes. Heat conduction, mass conservation, and phase change equations are derived in a simplified two-dimensional approach. Each differential equation is non-linearly coupled to the others through phase change. The microstructural network is then discretized into elements and nodes. Finite difference equations are developed for the network, and numerically solved using iterative techniques. The finite difference model provides a unique platform to study the influence of numerous geometric and thermodynamic parameters relating to dry snow metamorphism. Numerical metamorphism studies in an equi-temperature environment agree well with established trends and published experimental results.