Automated Terminus Detection for Greenland's Peripheral Marine-terminating Glaciers PDF Download
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Author: Julia Liu Publisher: ISBN: Category : Glaciers Languages : en Pages : 45
Book Description
"Changes in the length of marine-terminating glaciers strongly influence the mass balance of glaciers, ice caps, and ice sheets. Currently, quantification of glacier length change through measurement of terminus position relies on time-consuming and subjective manual mapping techniques, limiting our ability to understand the dynamics controlling glacier terminus changes. I developed an automated method of mapping glacier terminus positions in satellite imagery using observations from a representative sample of Greenlands peripheral glaciers. The method is adapted from the 2D Wavelet Transform Modulus Maxima (WTMM) segmentation method, which has been used previously for image segmentation in biomedical and other applied science fields. The gradient-based method places edge detection lines along regions with the greatest gradient in intensity in the image, such as the contrast between glacier ice and water or glacier ice and sea ice. I quantified the accuracy of the automated method with reference to a validation dataset consisting of over 500 manual delineations and determined that the automated method is capable of mapping glacier termini over a wide range of image conditions (light to intermediate cloud cover, uniformly dim or bright lighting, etc.) within 1-pixel uncertainty. These time series generated automatically from Landsat images (which have a frequent repeat interval and a long record of images) are capable of resolving sub-seasonal to multiannual temporal patterns as well as regional patterns in terminus change for these glaciers. The terminus position time series generated from this automated method indicate that the marine-terminating peripheral glaciers in southeast Greenland undergo synchronous terminus retreat in 2016-17. Initial exploration of regional atmospheric and ocean conditions links this synchronous retreat to subsurface ocean warming and increased surface runoff."--Boise State University ScholarWorks.
Author: Julia Liu Publisher: ISBN: Category : Glaciers Languages : en Pages : 45
Book Description
"Changes in the length of marine-terminating glaciers strongly influence the mass balance of glaciers, ice caps, and ice sheets. Currently, quantification of glacier length change through measurement of terminus position relies on time-consuming and subjective manual mapping techniques, limiting our ability to understand the dynamics controlling glacier terminus changes. I developed an automated method of mapping glacier terminus positions in satellite imagery using observations from a representative sample of Greenlands peripheral glaciers. The method is adapted from the 2D Wavelet Transform Modulus Maxima (WTMM) segmentation method, which has been used previously for image segmentation in biomedical and other applied science fields. The gradient-based method places edge detection lines along regions with the greatest gradient in intensity in the image, such as the contrast between glacier ice and water or glacier ice and sea ice. I quantified the accuracy of the automated method with reference to a validation dataset consisting of over 500 manual delineations and determined that the automated method is capable of mapping glacier termini over a wide range of image conditions (light to intermediate cloud cover, uniformly dim or bright lighting, etc.) within 1-pixel uncertainty. These time series generated automatically from Landsat images (which have a frequent repeat interval and a long record of images) are capable of resolving sub-seasonal to multiannual temporal patterns as well as regional patterns in terminus change for these glaciers. The terminus position time series generated from this automated method indicate that the marine-terminating peripheral glaciers in southeast Greenland undergo synchronous terminus retreat in 2016-17. Initial exploration of regional atmospheric and ocean conditions links this synchronous retreat to subsurface ocean warming and increased surface runoff."--Boise State University ScholarWorks.
Author: Carlos R. Mechoso Publisher: Cambridge University Press ISBN: 1108492703 Category : Science Languages : en Pages : 359
Book Description
A comprehensive review of interactions between the climates of different ocean basins and their key contributions to global climate variability and change. Providing essential theory and discussing outstanding examples as well as impacts on monsoons, it a useful resource for graduate students and researchers in the atmospheric and ocean sciences.
Author: Joseph R. Geraci Publisher: National Aquarium in Baltimore ISBN: 0977460908 Category : Marine mammals Languages : en Pages : 386
Book Description
Comprehensive manual for understanding and carrying out marine mammal rescue activities for stranded seals, manatees, dolphins, whales, or sea otters.
Author: National Research Council Publisher: National Academies Press ISBN: 0309301866 Category : Science Languages : en Pages : 240
Book Description
Once ice-bound, difficult to access, and largely ignored by the rest of the world, the Arctic is now front and center in the midst of many important questions facing the world today. Our daily weather, what we eat, and coastal flooding are all interconnected with the future of the Arctic. The year 2012 was an astounding year for Arctic change. The summer sea ice volume smashed previous records, losing approximately 75 percent of its value since 1980 and half of its areal coverage. Multiple records were also broken when 97 percent of Greenland's surface experienced melt conditions in 2012, the largest melt extent in the satellite era. Receding ice caps in Arctic Canada are now exposing land surfaces that have been continuously ice covered for more than 40,000 years. What happens in the Arctic has far-reaching implications around the world. Loss of snow and ice exacerbates climate change and is the largest contributor to expected global sea level rise during the next century. Ten percent of the world's fish catches comes from Arctic and sub-Arctic waters. The U.S. Geological Survey estimated that up to 13 percent of the world's remaining oil reserves are in the Arctic. The geologic history of the Arctic may hold vital clues about massive volcanic eruptions and the consequent release of massive amount of coal fly ash that is thought to have caused mass extinctions in the distant past. How will these changes affect the rest of Earth? What research should we invest in to best understand this previously hidden land, manage impacts of change on Arctic communities, and cooperate with researchers from other nations? The Arctic in the Anthropocene reviews research questions previously identified by Arctic researchers, and then highlights the new questions that have emerged in the wake of and expectation of further rapid Arctic change, as well as new capabilities to address them. This report is meant to guide future directions in U.S. Arctic research so that research is targeted on critical scientific and societal questions and conducted as effectively as possible. The Arctic in the Anthropocene identifies both a disciplinary and a cross-cutting research strategy for the next 10 to 20 years, and evaluates infrastructure needs and collaboration opportunities. The climate, biology, and society in the Arctic are changing in rapid, complex, and interactive ways. Understanding the Arctic system has never been more critical; thus, Arctic research has never been more important. This report will be a resource for institutions, funders, policy makers, and students. Written in an engaging style, The Arctic in the Anthropocene paints a picture of one of the last unknown places on this planet, and communicates the excitement and importance of the discoveries and challenges that lie ahead.
Author: Jeffrey S. Kargel Publisher: Springer ISBN: 3540798188 Category : Technology & Engineering Languages : en Pages : 936
Book Description
An international team of over 150 experts provide up-to-date satellite imaging and quantitative analysis of the state and dynamics of the glaciers around the world, and they provide an in-depth review of analysis methodologies. Includes an e-published supplement. Global Land Ice Measurements from Space - Satellite Multispectral Imaging of Glaciers (GLIMS book for short) is the leading state-of-the-art technical and interpretive presentation of satellite image data and analysis of the changing state of the world's glaciers. The book is the most definitive, comprehensive product of a global glacier remote sensing consortium, Global Land Ice Measurements from Space (GLIMS, http://www.glims.org). With 33 chapters and a companion e-supplement, the world's foremost experts in satellite image analysis of glaciers analyze the current state and recent and possible future changes of glaciers across the globe and interpret these findings for policy planners. Climate change is with us for some time to come, and its impacts are being felt by the world's population. The GLIMS Book, to be released about the same time as the IPCC's 5th Assessment report on global climate warming, buttresses and adds rich details and authority to the global change community's understanding of climate change impacts on the cryosphere. This will be a definitive and technically complete reference for experts and students examining the responses of glaciers to climate change. World experts demonstrate that glaciers are changing in response to the ongoing climatic upheaval in addition to other factors that pertain to the circumstances of individual glaciers. The global mosaic of glacier changes is documented by quantitative analyses and are placed into a perspective of causative factors. Starting with a Foreword, Preface, and Introduction, the GLIMS book gives the rationale for and history of glacier monitoring and satellite data analysis. It includes a comprehensive set of six "how-to" methodology chapters, twenty-five chapters detailing regional glacier state and dynamical changes, and an in-depth summary and interpretation chapter placing the observed glacier changes into a global context of the coupled atmosphere-land-ocean system. An accompanying e-supplement will include oversize imagery and other other highly visual renderings of scientific data.
Author: Intergovernmental Panel on Climate Change (IPCC) Publisher: Cambridge University Press ISBN: 9781009157971 Category : Science Languages : en Pages : 755
Book Description
The Intergovernmental Panel on Climate Change (IPCC) is the leading international body for assessing the science related to climate change. It provides policymakers with regular assessments of the scientific basis of human-induced climate change, its impacts and future risks, and options for adaptation and mitigation. This IPCC Special Report on the Ocean and Cryosphere in a Changing Climate is the most comprehensive and up-to-date assessment of the observed and projected changes to the ocean and cryosphere and their associated impacts and risks, with a focus on resilience, risk management response options, and adaptation measures, considering both their potential and limitations. It brings together knowledge on physical and biogeochemical changes, the interplay with ecosystem changes, and the implications for human communities. It serves policymakers, decision makers, stakeholders, and all interested parties with unbiased, up-to-date, policy-relevant information. This title is also available as Open Access on Cambridge Core.
Author: Jonathan L. Carrivick Publisher: John Wiley & Sons ISBN: 1118895827 Category : Technology & Engineering Languages : en Pages : 208
Book Description
Structure from Motion with Multi View Stereo provides hyperscale landform models using images acquired from standard compact cameras and a network of ground control points. The technique is not limited in temporal frequency and can provide point cloud data comparable in density and accuracy to those generated by terrestrial and airborne laser scanning at a fraction of the cost. It therefore offers exciting opportunities to characterise surface topography in unprecedented detail and, with multi-temporal data, to detect elevation, position and volumetric changes that are symptomatic of earth surface processes. This book firstly places Structure from Motion in the context of other digital surveying methods and details the Structure from Motion workflow including available software packages and assessments of uncertainty and accuracy. It then critically reviews current usage of Structure from Motion in the geosciences, provides a synthesis of recent validation studies and looks to the future by highlighting opportunities arising from developments in allied disciplines. This book will appeal to academics, students and industry professionals because it balances technical knowledge of the Structure from Motion workflow with practical guidelines for image acquisition, image processing and data quality assessment and includes case studies that have been contributed by experts from around the world.
Author: John A. Eddy Publisher: Government Printing Office ISBN: 9780160838088 Category : Business & Economics Languages : en Pages : 316
Book Description
" ... Concise explanations and descriptions - easily read and readily understood - of what we know of the chain of events and processes that connect the Sun to the Earth, with special emphasis on space weather and Sun-Climate."--Dear Reader.
Author: Julia Liu
Author: Julia Liu
Author: Carlos R. Mechoso
Author: Joseph R. Geraci
Author: National Research Council
Author: Jeffrey S. Kargel
Author: Intergovernmental Panel on Climate Change (IPCC)
Author: Anker Weidick
Author: U.S. Geological Survey
Author: Jonathan L. Carrivick
Author: John A. Eddy