Download or read book Spatial Heterogeneity and Seasonal Evolution of Surface Properties and Radiative Fluxes of Arctic Sea Ice written by Ran Tao and published by . This book was released on 2024 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: In recent years, the Arctic sea ice has experienced a significant decline, characterised by the smaller extent, longer melt season, and a shift from thick multi-year ice to thinner first-year ice. As a result, more solar radiative energy is deposited into the Arctic sea ice and the ocean underneath, further enhancing sea ice melt and ocean heat. When the Arctic is transitioning from melt onset to freeze onset, the sea ice surface spatial variability becomes stronger, altering the spatial distribution of radiative energy deposition. Understanding the seasonal evolution and spatial variability of solar radiative fluxes is a key step to broadening our knowledge of the changing Arctic sea ice. In this thesis, I investigate the year-round changes in solar radiative fluxes within the Arctic sea ice, both temporally and spatially. I examine the changes in optical properties during the Multidisciplinary drifting Observatory for the Study of Arctic Climate expedition (MOSAiC) in 2020. This thesis utilises a wide range of sensors and platforms, ranging from long-term continuous point measurement, to weekly under-ice mapping of light field, and to ice-floe size parameterization. This thesis highlights the spatial variability of the solar radiative fluxes of Arctic sea ice: under the same atmospheric condition and located on the same ice floe, different locations show highly variable evolution. The largest variability is in the middle of the melt season, due to the changing melt pond coverage and status. The sea ice types and surface conditions are crucial for the sea ice energy budget, thus further controlling the melting process. This thesis provides a comprehensive 3-dimensional view of the sea ice radiative fluxes and improves the parameterization of sea ice optical properties. Also, by investigating the effects of spatial surface variability, which is a function of time and area, this thesis guides future observations of the new Arctic sea ice regime. This study bridges in-situ observation to floe-size parameterisation, advances our understanding of the upscaling of solar radiative energy fluxes both onto and through the Arctic sea ice, and deepens our understanding of the impact of sea ice heterogeneity on the large-scale energy budget of the melting Arctic sea ice.
Download or read book The Sensitivity of Arctic Sea Ice to Cloud Radiative Conditions in Spring and Early Summer written by Michalea D. King and published by . This book was released on 2016 with total page 105 pages. Available in PDF, EPUB and Kindle. Book excerpt: The rapid decline in Arctic sea ice is a key driver of the amplified warming signal observed in the Arctic region, making this a critical phenomenon in climate science. Accurate seasonal sea ice projections, however, remain challenging due to a large degree of interannual variability in sea ice extent. This study analyzed the role of clouds in the early melt season, and their associated surface radiative effects, in modulating the magnitude of sea ice loss. A combination of observed and modeled sea ice thickness data was used to track temporal and spatial patterns of sea ice volume loss. A stepwise multiple linear regression analysis revealed that variants of Arctic cloud radiative fluxes in March and June were valuable in predicting the total volume of sea ice loss during the melt season. This study then explored the causalities behind the particular variable selection by the regression model, which yielded an adjusted R2 value of 0.88. Downwelling longwave cloud radiative fluxes in March were found to be negatively correlated with melt onset, with enhanced downward fluxes initiating earlier melt. Downwelling longwave fluxes in June were interpreted to be significant due to the large volume of ice volume lost in June, as well as the heightened effect of clouds on the surface radiative budget during periods of maximum insolation. Sea ice loss can also be influenced by the spatial patterns and magnitude of sea ice advection. Anomalous surface wind conditions and resulting anomalies in sea ice advection, were found to be critical in 2013, a year that fell outside the confidence interval of the regression model.
Download or read book Sea Ice written by David N. Thomas and published by John Wiley & Sons. This book was released on 2008-04-15 with total page 419 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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
Download or read book An Investigation of the Arctic Sea Ice Surface written by Melinda A. Webster and published by . This book was released on 2016 with total page 136 pages. Available in PDF, EPUB and Kindle. Book excerpt: The oldest records of the Arctic sea ice pack illustrate a frozen, yet dynamic icescape composed of hummocks and weathered ridges draped in thick snow. In recent decades, the effects of climate change have transformed this image: the Arctic sea ice pack is younger, thinner, and more dynamic. As a result, the properties of its surface are changing and impacting its ice mass balance. This work investigates the recent geophysical changes of the Arctic sea ice surface, giving emphasis to snow, melt ponds, and sea ice surface topography through the three following papers: (1) interdecadal changes in spring snow depth, (2) seasonal evolution of melt ponds, and (3) the spatial scaling of melt pond distributions. In the first analysis, recent in situ and airborne observations were used to extend the snow climatology to the contemporary period. Through this, we were able to identify the interdecadal change in spring snow depth distributions, and found that snow has thinned by 37 ± 29% in the western Arctic and 56 ± 33% in the Beaufort and Chukchi seas. The decrease was attributed to later autumnal sea ice formation. During the peak snowfall period in autumn, snow falls into the ocean and melts due to the absence of sea ice. In the second analysis, an algorithm was developed for identifying melt ponds in high-resolution satellite images of a Lagrangian site. The site was composed mixed sea ice types, allowing for a comparison of seasonal melt pond evolution between first-year and multiyear sea ice undergoing the same forcings. Surprisingly, melt ponds formed three weeks earlier on multiyear sea ice than first-year sea ice. Nearly half of the snow on the multiyear sea ice was optically-thin, which likely contributed to early melt pond formation. The uniformity in melt pond formation, drainage, and distribution was inversely proportional to the level of sea ice deformation; melt pond uniformity increased with decreasing sea ice deformation. The third analysis investigated the spatial scaling of melt pond distributions at two sites with homogenous (undeformed first-year) and heterogeneous (mixed deformation and age) sea ice. The relationship between small-scale variability in melt pond geometries and aggregate-scale estimates of melt pond fractions was examined. The results revealed that: (1) melt pond geometry is most variable before melt pond drainage at the heterogeneous site, but after melt pond drainage at the homogenous site, (2) aggregate-scale estimates of melt pond fractions in homogenous and heterogeneous sea ice sites are larger than previously recognized, ranging from ~70 km2 to ~480 km2, and (3) aggregate-scale estimates of melt pond fractions may be dependent on the composition of sea ice types and stage of melt pond evolution.
Download or read book Sea Ice in the Arctic written by Ola M. Johannessen and published by Springer Nature. This book was released on 2019-11-12 with total page 575 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides in-depth information about the sea ice in the Arctic at scales from paleoenvironmental variability to more contemporary changes during the past and present centuries. The book is based on several decades of research related to sea ice in the Arctic and its variability, sea ice process studies as well as implications of the sea ice variability on human activities. The chapters provide an extensive overview of the research results related to sea ice in the Arctic at paleo-scales to more resent scales of variations as well as projections for changes during the 21st century. The authors have pioneered the satellite remote sensing monitoring of sea ice and used other monitoring data in order to study, monitor and model sea ice and its processes.
Download or read book Seasonal to Decadal Predictions of Arctic Sea Ice written by National Research Council and published by National Academies Press. This book was released on 2013-01-03 with total page 93 pages. Available in PDF, EPUB and Kindle. Book excerpt: Recent well documented reductions in the thickness and extent of Arctic sea ice cover, which can be linked to the warming climate, are affecting the global climate system and are also affecting the global economic system as marine access to the Arctic region and natural resource development increase. Satellite data show that during each of the past six summers, sea ice cover has shrunk to its smallest in three decades. The composition of the ice is also changing, now containing a higher fraction of thin first-year ice instead of thicker multi-year ice. Understanding and projecting future sea ice conditions is important to a growing number of stakeholders, including local populations, natural resource industries, fishing communities, commercial shippers, marine tourism operators, national security organizations, regulatory agencies, and the scientific research community. However, gaps in understanding the interactions between Arctic sea ice, oceans, and the atmosphere, along with an increasing rate of change in the nature and quantity of sea ice, is hampering accurate predictions. Although modeling has steadily improved, projections by every major modeling group failed to predict the record breaking drop in summer sea ice extent in September 2012. Establishing sustained communication between the user, modeling, and observation communities could help reveal gaps in understanding, help balance the needs and expectations of different stakeholders, and ensure that resources are allocated to address the most pressing sea ice data needs. Seasonal-to-Decadal Predictions of Arctic Sea Ice: Challenges and Strategies explores these topics.
Download or read book Report written by Arctic System Science Ocean-Atmosphere-Ice Interactions (Program) and published by . This book was released on with total page 102 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Arctic Sea Ice Decline written by Eric T. DeWeaver and published by John Wiley & Sons. This book was released on 2013-05-28 with total page 431 pages. Available in PDF, EPUB and Kindle. Book excerpt: Published by the American Geophysical Union as part of the Geophysical Monograph Series, Volume 180. This volume addresses the rapid decline of Arctic sea ice, placing recent sea ice decline in the context of past observations, climate model simulations and projections, and simple models of the climate sensitivity of sea ice. Highlights of the work presented here include An appraisal of the role played by wind forcing in driving the decline; A reconstruction of Arctic sea ice conditions prior to human observations, based on proxy data from sediments; A modeling approach for assessing the impact of sea ice decline on polar bears, used as input to the U.S. Fish and Wildlife Service's decision to list the polar bear as a threatened species under the Endangered Species Act; Contrasting studies on the existence of a "tipping point," beyond which Arctic sea ice decline will become (or has already become) irreversible, including an examination of the role of the small ice cap instability in global warming simulations; A significant summertime atmospheric response to sea ice reduction in an atmospheric general circulation model, suggesting a positive feedback and the potential for short-term climate prediction. The book will be of interest to researchers attempting to understand the recent behavior of Arctic sea ice, model projections of future sea ice loss, and the consequences of sea ice loss for the natural and human systems of the Arctic.
Download or read book Impacts of Snow and Surface Conditions on Radiation Fluxes Through Arctic Sea Ice During Different Seasons written by Philipp Anhaus and published by . This book was released on 2022 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Sea ice and its snow cover play a key role within the climate and ecosystem. Due to global environmental changes which are amplified in the Arctic Ocean, its sea-ice cover will primarily consist of thin and young sea ice with a reduction in extent. In particular, the area where snow accumulates reduces and the fraction of melt-pond covered sea ice and of openings in the sea-ice cover such as leads increase. Those changes of the surface conditions strongly influence the partitioning of solar radiation. The main objective of this dissertation was to establish relationships between the surface conditions that are observed and expected to dominate in the future Arctic and under-ice radiation. A deeper and broader knowledge of such relationships is especially necessary in spring and autumn during which the under-ice radiation can have significant impacts on the annual energy budget. To achieve that, field measurements collected using a variety of instruments during three campaigns for three different sea-ice types, locations, and seasons were analysed and interpreted. A main result was to derive a new parametrization for snow depth retrieval from spectral under ice-radiation measurements. This was successfully achieved with an accuracy of approximately 5 cm for two ice types, in two locations, during two seasons. In contrast to the established theory that melt ponds act as bright windows to the underlying ocean, it was possible to document and analyse cases where a thicker snow cover accumulated on melt ponds compared to on adjacent bare ice. This resulted, surprisingly, in lower levels of under-ice radiation underneath the melt ponds than underneath bare ice. New analyses of relationships between thermodynamics and optics of a refreezing lead and thin ice suggest that radiative transfer in thin ice is often not accurately accounted for using bulk formulations, as they are applicable for thicker ice. The initial states of the lead's opening and refreezing need to be treated separately and cannot generally be considered windows into the ocean. This dissertation extended our knowledge of the relationships between snow and surface conditions and under-ice radiation. The results point towards impacts on sea-ice energy balance, ocean heat content, thermodynamic ice growth, and ice-and ocean-associated ecosystem activity.
Download or read book Sea Ice written by David N. Thomas and published by John Wiley & Sons. This book was released on 2017-03-06 with total page 666 pages. Available in PDF, EPUB and Kindle. Book excerpt: Over the past 20 years the study of the frozen Arctic and Southern Oceans and sub-arctic seas has progressed at a remarkable pace. This third edition of Sea Ice gives insight into the very latest understanding of the how sea ice is formed, how we measure (and model) its extent, the biology that lives within and associated with sea ice and the effect of climate change on its distribution. How sea ice influences the oceanography of underlying waters and the influences that sea ice has on humans living in Arctic regions are also discussed. Featuring twelve new chapters, this edition follows two previous editions (2001 and 2010), and the need for this latest update exhibits just how rapidly the science of sea ice is developing. The 27 chapters are written by a team of more than 50 of the worlds’ leading experts in their fields. These combine to make the book the most comprehensive introduction to the physics, chemistry, biology and geology of sea ice that there is. This third edition of Sea Ice will be a key resource for all policy makers, researchers and students who work with the frozen oceans and seas.
Download or read book Sea Ice Bridging Spatial Temporal Scales and Disciplines written by Hauke Flores and published by Frontiers Media SA. This book was released on 2020-06-25 with total page 155 pages. Available in PDF, EPUB and Kindle. Book excerpt: This eBook is a collection of articles from a Frontiers Research Topic. Frontiers Research Topics are very popular trademarks of the Frontiers Journals Series: they are collections of at least ten articles, all centered on a particular subject. With their unique mix of varied contributions from Original Research to Review Articles, Frontiers Research Topics unify the most influential researchers, the latest key findings and historical advances in a hot research area! Find out more on how to host your own Frontiers Research Topic or contribute to one as an author by contacting the Frontiers Editorial Office: frontiersin.org/about/contact.
Download or read book Field Techniques for Sea Ice Research written by Hajo Eicken and published by University of Alaska Press. This book was released on 2010-03-15 with total page 590 pages. Available in PDF, EPUB and Kindle. Book excerpt: As much as one-tenth of the world’s oceans are covered with sea ice, or frozen ocean water, at some point during the annual cycle. Sea ice thus plays an important, often defining, role in the natural environment and the global climate system. This book is a global look at the changes in sea ice and the tools and techniques used to measure and record those changes. The first comprehensive research done on sea-ice field techniques, this volume will be indispensable for the study of northern sea ice and a must-have for scientists in the field of climate change research.
Download or read book The Geophysics of Sea Ice written by Norbert Untersteiner and published by Springer. This book was released on 2013-12-19 with total page 1197 pages. Available in PDF, EPUB and Kindle. Book excerpt: Based on the proceedings of the NATO Advanced Study Institute on Air-Sea-Ice Interaction held September 28-October 10, 1981 in Acquafredda di maratea, Italy. Intent is to present the topic of sea ice in the broad and interdisciplinary context of atmospheric and oceanographic science.
Download or read book The Arctic in the Anthropocene written by National Research Council and published by National Academies Press. This book was released on 2014-07-31 with total page 240 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Download or read book Arctic Climate Characteristics and Recent Trends from Space written by Xuanji Wang and published by . This book was released on 2003 with total page 176 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Dissertation Abstracts International written by and published by . This book was released on 2009 with total page 810 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Observing and Modeling the Surface Scattering Layer of First Year Arctic Sea Ice written by and published by . This book was released on 2007 with total page 8 pages. Available in PDF, EPUB and Kindle. Book excerpt: The goal of this work is to increase our quantitative understanding of the partitioning of incident solar (shortwave) radiation by sea ice. The partitioning of shortwave radiation into components backscattered to the atmosphere, absorbed by the ice, and transmitted to the ocean is central to the ice-albedo feedback mechanism, the mean annual cycle of ice thickness, mechanical properties of the ice, and the quality and quantity of light available to under-ice biological communities. This partitioning is known to depend on the presence of surface scattering layers (SSLs). We conducted field observations and model simulations of radiative transfer within the surface layer and interior layers of sea ice. Results have been used to improve characterization of the properties of bare and ponded ice for the purpose of understanding the surface energy and mass balances of sea ice during summer. Three broad concepts have emerged from this work: (i) a 3-layer structure for specifying the vertical variation of optical properties of both bare and ponded sea ice, (ii) the optical properties found in the ice interior are independent of time, and (iii) a picture of the evolution of scattering near the surface of bare and ponded ice as the melt season progresses.
