Author: National Research Council
Publisher: National Academies Press
ISBN: 0309301246
Category : Science
Languages : en
Pages : 171
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Book Description
Permafrost is a thermal condition-its formation, persistence and disappearance are highly dependent on climate. General circulation models predict that, for a doubling of atmospheric concentrations of carbon dioxide, mean annual air temperatures may rise up to several degrees over much of the Arctic. In the discontinuous permafrost region, where ground temperatures are within 1-2 degrees of thawing, permafrost will likely ultimately disappear as a result of ground thermal changes associated with global climate warming. Where ground ice contents are high, permafrost degradation will have associated physical impacts. Permafrost thaw stands to have wide-ranging impacts, such as the draining and drying of the tundra, erosion of riverbanks and coastline, and destabilization of infrastructure (roads, airports, buildings, etc.), and including potential implications for ecosystems and the carbon cycle in the high latitudes. Opportunities to Use Remote Sensing in Understanding Permafrost and Related Ecological Characteristics is the summary of a workshop convened by the National Research Council to explore opportunities for using remote sensing to advance our understanding of permafrost status and trends and the impacts of permafrost change, especially on ecosystems and the carbon cycle in the high latitudes. The workshop brought together experts from the remote sensing community with permafrost and ecosystem scientists. The workshop discussions articulated gaps in current understanding and potential opportunities to harness remote sensing techniques to better understand permafrost, permafrost change, and implications for ecosystems in permafrost areas. This report addresses questions such as how remote sensing might be used in innovative ways, how it might enhance our ability to document long-term trends, and whether it is possible to integrate remote sensing products with the ground-based observations and assimilate them into advanced Arctic system models. Additionally, the report considers the expectations of the quality and spatial and temporal resolution possible through such approaches, and the prototype sensors that are available that could be used for detailed ground calibration of permafrost/high latitude carbon cycle studies.
Author:
Publisher:
ISBN: 9780309302319
Category :
Languages : en
Pages :
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Book Description
Author: Ni-Bin Chang
Publisher: CRC Press
ISBN: 1351650637
Category : Technology & Engineering
Languages : en
Pages : 627
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Book Description
In the last few years the scientific community has realized that obtaining a better understanding of interactions between natural systems and the man-made environment across different scales demands more research efforts in remote sensing. An integrated Earth system observatory that merges surface-based, air-borne, space-borne, and even underground sensors with comprehensive and predictive capabilities indicates promise for revolutionizing the study of global water, energy, and carbon cycles as well as land use and land cover changes. The aim of this book is to present a suite of relevant concepts, tools, and methods of integrated multisensor data fusion and machine learning technologies to promote environmental sustainability. The process of machine learning for intelligent feature extraction consists of regular, deep, and fast learning algorithms. The niche for integrating data fusion and machine learning for remote sensing rests upon the creation of a new scientific architecture in remote sensing science that is designed to support numerical as well as symbolic feature extraction managed by several cognitively oriented machine learning tasks at finer scales. By grouping a suite of satellites with similar nature in platform design, data merging may come to help for cloudy pixel reconstruction over the space domain or concatenation of time series images over the time domain, or even both simultaneously. Organized in 5 parts, from Fundamental Principles of Remote Sensing; Feature Extraction for Remote Sensing; Image and Data Fusion for Remote Sensing; Integrated Data Merging, Data Reconstruction, Data Fusion, and Machine Learning; to Remote Sensing for Environmental Decision Analysis, the book will be a useful reference for graduate students, academic scholars, and working professionals who are involved in the study of Earth systems and the environment for a sustainable future. The new knowledge in this book can be applied successfully in many areas of environmental science and engineering.
Author: National Academies of Sciences, Engineering, and Medicine
Publisher: National Academies Press
ISBN: 0309467608
Category : Science
Languages : en
Pages : 717
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Book Description
We live on a dynamic Earth shaped by both natural processes and the impacts of humans on their environment. It is in our collective interest to observe and understand our planet, and to predict future behavior to the extent possible, in order to effectively manage resources, successfully respond to threats from natural and human-induced environmental change, and capitalize on the opportunities â€" social, economic, security, and more â€" that such knowledge can bring. By continuously monitoring and exploring Earth, developing a deep understanding of its evolving behavior, and characterizing the processes that shape and reshape the environment in which we live, we not only advance knowledge and basic discovery about our planet, but we further develop the foundation upon which benefits to society are built. Thriving on Our Changing Planet presents prioritized science, applications, and observations, along with related strategic and programmatic guidance, to support the U.S. civil space Earth observation program over the coming decade.
Author: National Research Council
Publisher: National Academies Press
ISBN: 0309371619
Category : Science
Languages : en
Pages : 37
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Book Description
Viewed in satellite images as a jagged white coat draped over the top of the globe, the high Arctic appears distant and isolated. But even if you don't live there, don't do business there, and will never travel there, you are closer to the Arctic than you think. Arctic Matters: The Global Connection to Changes in the Arctic is a new educational resource produced by the Polar Research Board of the National Research Council (NRC). It draws upon a large collection of peer-reviewed NRC reports and other national and international reports to provide a brief, reader-friendly primer on the complex ways in which the changes currently affecting the Arctic and its diverse people, resources, and environment can, in turn, affect the entire globe. Topics in the booklet include how climate changes currently underway in the Arctic are a driver for global sea-level rise, offer new prospects for natural resource extraction, and have rippling effects through the world's weather, climate, food supply and economy.
Author: Jinyang Du
Publisher: MDPI
ISBN: 3039215701
Category : Technology & Engineering
Languages : en
Pages : 210
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Book Description
This Special Issue gathers papers reporting recent advances in the remote sensing of cold regions. It includes contributions presenting improvements in modeling microwave emissions from snow, assessment of satellite-based sea ice concentration products, satellite monitoring of ice jam and glacier lake outburst floods, satellite mapping of snow depth and soil freeze/thaw states, near-nadir interferometric imaging of surface water bodies, and remote sensing-based assessment of high arctic lake environment and vegetation recovery from wildfire disturbances in Alaska. A comprehensive review is presented to summarize the achievements, challenges, and opportunities of cold land remote sensing.
Author: Zachary Lance Langford
Publisher:
ISBN:
Category : Arctic regions
Languages : en
Pages : 181
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Book Description
Amplified warming in the Arctic has likely increased the rate of landscape change and disturbances in northern high latitude regions. Satellite remote sensing is a valuable tool for monitoring natural and anthropogenic changes occurring in remote, northern high latitude environments over multiple time scales. It offers the potential to characterize the vegetation, land cover, hydrology, geomorphology and permafrost characteristics of the Arctic landscape and improve and improve our understanding of changes these ecosystems are undergoing due to effect of natural and anthropogenic climate change and changing disturbance regimes. Combined with ground based observations of ecological processes, remote sensing offers opportunities for upscaling the ground based measurements to better understand the larger landscape. In this dissertation research I have developed 1) new techniques for integration of remote sensing data set from a range of platforms with different spatial and temporal resolutions; 2) computationally efficient statistical and machine learning techniques to get ecological insights from large volumes of high dimensional remote sensing data; 3) methods to characterize and map vegetation characteristics at NGEE Arctic field sites in Alaska; and 4) techniques for identification and attribution of disturbance regimes in Alaska. In a close partnership with field ecologist, geospatial and machine learning techniques I have developed in this research has led to new insights and high resolution datasets of Arctic vegetation processes.
Author: Daqing Yang
Publisher: Springer Nature
ISBN: 3030509303
Category : Science
Languages : en
Pages : 914
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Book Description
This book provides a comprehensive, up-to-date assessment of the key terrestrial components of the Arctic system, i.e., its hydrology, permafrost, and ecology, drawing on the latest research results from across the circumpolar regions. The Arctic is an integrated system, the elements of which are closely linked by the atmosphere, ocean, and land. Using an integrated system approach, the book’s 30 chapters, written by a diverse team of leading scholars, carefully examine Arctic climate variability/change, large river hydrology, lakes and wetlands, snow cover and ice processes, permafrost characteristics, vegetation/landscape changes, and the future trajectory of Arctic system evolution. The discussions cover the fundamental features of and processes in the Arctic system, with a special focus on critical knowledge gaps, i.e., the interactions and feedbacks between water, permafrost, and ecosystem, such as snow pack and permafrost changes and their impacts on basin hydrology and ecology, river flow, geochemistry, and energy fluxes to the Arctic Ocean, and the structure and function of the Arctic ecosystem in response to past/future changes in climate, hydrology, and permafrost conditions. Given its scope, the book offers a valuable resource for researchers, graduate students, environmentalists, managers, and administrators who are concerned with the northern environment and resources.
Author: Eva Stephani
Publisher:
ISBN:
Category : Erosion
Languages : en
Pages : 664
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Book Description
The Arctic and its permafrost terrain are inherently dynamic, complex, and sensitive environments. Understanding the past and current changes occurring in these systems is key in predicting future variations, including the response of permafrost to climate change, and to terrain modifications resulting from natural processes or anthropogenic activities. This study contributes to advance our understanding of permafrost dynamics in varying permafrost environments of northern Alaska and northwestern Canada using a terrain-cryofacies approach. This unique approach helps to increase our understanding of permafrost dynamics from the site-specific scale to over extended areas by recognizing linkages between terrain and subsurface properties, and by identifying similar terrain units in remote sensing analysis. In the Colville River Delta (Alaska), our terrain-cryofacies study integrated data from 79 boreholes with a remote sensing analysis to evaluate the temporal changes in the Nigliq channel positions from 1948 to 2013 and the related permafrost dynamics. Most land cover changes occurred as land exposition (64%), whereas about 36% of the total changes were classified as eroded. The erosion of the older terrain units from the floodplain toposequence, such as the inactive-floodplain cover deposits, implied ground loss volumes of about one-fifth of soil solids and four-fifths of ground ice. Along this channel, we also identified the typical configuration and properties of taliks and cryopegs, as well as subsequent epigenetic permafrost growth. We found that the active channel was underlain by closed taliks, rather than through taliks and thus did not penetrate the entire layer of permafrost connecting supra- and sub-permafrost groundwater. A cryopeg connected to the active channel talik was identified from borehole data in the adjacent terrain units that developed following channel migration. We estimated the likelihood of encountering such taliks and cryopegs over extended areas. The terrain-cryofacies approach was also applied to understand permafrost dynamics of hillslope thermokarst located in multiple ecoregions of northern Alaska and northwestern Canada, including areas affected by interactions with infrastructure. Six features were studied through the combination of field-based and remote sensing methods, whereas 150 others were assessed solely by remote sensing. Studies along a pipeline indicated that embankment construction led to an increase in the active layer thickness, reaching the underlying ice-rich intermediate layer, and causing thaw settlement. This formed a thermokarst-ditch that facilitated channelization of cross-drainage water, and thermal erosion of the ice-rich permafrost that became affected by thermal denudation and caused a retrogressive thaw slump (RTS). The RTS later selfstabilized mainly due to the lateral discontinuity of massive ice (i.e., ice wedge) and the low-relief terrain. We suggested approaches to develop adaptation strategies for infrastructure at risk of RTS based on: these findings and conditions that favor or limit RTS growth by local feedbacks; considering the interaction patterns that we identified between RTS and infrastructure; and the main destabilization processes that we highlighted by terrain units. Further research is necessary, however, and must include testing potential mitigation techniques at multiple sites with monitoring programs to assess the variability in performance with respect to site-specific conditions.
Author: Dana Rachel Nossov Brown
Publisher:
ISBN:
Category : Forest fires
Languages : en
Pages : 228
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Book Description
A warming climate is expected to cause widespread thawing of discontinuous permafrost, and the co-occurrence of wildfire may function to exacerbate this process. Here, I examined the vulnerability of permafrost to degradation from fire disturbance as it varies across different landscapes of the Interior Alaskan boreal forest using a combination of observational, modeling, and remote sensing approaches. Across all landscapes, the severity of burning strongly influenced both post-fire vegetation and permafrost degradation. The thickness of the remaining surface organic layer was a key control on permafrost degradation because its low thermal conductivity limits ground heat flux. Thus, variation in burn severity controlled the local distribution of near-surface permafrost. Mineral soil texture and permafrost ice content interacted with climate to influence the response of permafrost to fire. Permafrost was vulnerable to deep thawing after fire in coarse-textured or rocky soils throughout the region; low ice content likely enabled this rapid thawing. After thawing, increased drainage in coarse-textured soils caused reductions in surface soil moisture, which contributed to warmer soil temperatures. By contrast, permafrost in fine-textured soils was resilient to fire disturbance in the silty uplands of the Yukon Flats ecoregion, but was highly vulnerable to thawing in the silty lowlands of the Tanana Flats. The resilience of silty upland permafrost was attributed to higher water content of the active layer and the associated high latent heat content of the ice-rich permafrost, coupled with a relatively cold continental climate and sloping topography that removes surface water. In the Tanana Flats, permafrost in silty lowlands thawed after fire despite high water and ice content of soils. This thawing was associated with significant ground surface subsidence, which resulted in water impoundment on the flat terrain, generating a positive feedback to permafrost degradation and wetland expansion. The response of permafrost to fire, and its ecological effects, thus varied spatially due to complex interactions between climate, topography, vegetation, burn severity, soil properties, and hydrology. The sensitivity of permafrost to fire disturbance has also changed over time due to variation in weather at multi-year to multi-decadal time scales. Simulations of soil thermal dynamics showed that increased air temperature, increased snow accumulation, and their interactive effects, have since the 1970s caused permafrost to become more vulnerable to talik formation and deep thawing from fire disturbance. Wildfire coupled with climate change has become an important driver of permafrost loss and ecological change in the northern boreal forest. With continued climate warming, we expect fire disturbance to accelerate permafrost thawing and reduce the likelihood of permafrost recovery. This regime shift is likely to have strong effects on a suite of ecological characteristics of the boreal forest, including surface energy balance, soil moisture, nutrient cycling, vegetation composition, and ecosystem productivity.