Spatial Heterogeneity and Seasonal Evolution of Surface Properties and Radiative Fluxes of Arctic Sea Ice

Spatial Heterogeneity and Seasonal Evolution of Surface Properties and Radiative Fluxes of Arctic Sea Ice PDF Author: Ran Tao
Publisher:
ISBN:
Category :
Languages : en
Pages : 0

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Book Description
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.

Spatial Heterogeneity and Seasonal Evolution of Surface Properties and Radiative Fluxes of Arctic Sea Ice

Spatial Heterogeneity and Seasonal Evolution of Surface Properties and Radiative Fluxes of Arctic Sea Ice PDF Author: Ran Tao
Publisher:
ISBN:
Category :
Languages : en
Pages : 0

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Book Description
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.

The Sensitivity of Arctic Sea Ice to Cloud Radiative Conditions in Spring and Early Summer

The Sensitivity of Arctic Sea Ice to Cloud Radiative Conditions in Spring and Early Summer PDF Author: Michalea D. King
Publisher:
ISBN: 9781369353815
Category : Clouds
Languages : en
Pages : 105

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Book Description
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.

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

Sea Ice in the Arctic

Sea Ice in the Arctic PDF Author: Ola M. Johannessen
Publisher: Springer Nature
ISBN: 3030213013
Category : Technology & Engineering
Languages : en
Pages : 575

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Book Description
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.

Seasonal to Decadal Predictions of Arctic Sea Ice

Seasonal to Decadal Predictions of Arctic Sea Ice PDF Author: National Research Council
Publisher: National Academies Press
ISBN: 0309265266
Category : Science
Languages : en
Pages : 93

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Book Description
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.

Impacts of Snow and Surface Conditions on Radiation Fluxes Through Arctic Sea Ice During Different Seasons

Impacts of Snow and Surface Conditions on Radiation Fluxes Through Arctic Sea Ice During Different Seasons PDF Author: Philipp Anhaus
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Book Description
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.

Report

Report PDF Author: Arctic System Science Ocean-Atmosphere-Ice Interactions (Program)
Publisher:
ISBN:
Category : Arctic regions
Languages : en
Pages : 102

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Book Description


Arctic Sea Ice Decline

Arctic Sea Ice Decline PDF Author: Eric T. DeWeaver
Publisher: John Wiley & Sons
ISBN: 1118671589
Category : Science
Languages : en
Pages : 431

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Book Description
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.

Sea Ice

Sea Ice PDF Author: Mohammed Shokr
Publisher: John Wiley & Sons
ISBN: 1119828163
Category : Science
Languages : en
Pages : 628

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Book Description
SEA ICE The latest edition of the gold standard in sea ice references In the newly revised second edition of Sea Ice: Physics and Remote Sensing, a team of distinguished researchers delivers an in-depth review of the features and structural properties of ice, as well as the latest advances in geophysical sensors, ice parameter retrieval techniques, and remote sensing data. The book has been updated to reflect the latest scientific developments in macro- and micro-scale sea ice research. For this edition, the authors have included high-quality photographs of thin sections from cores of various ice types, as well as a comprehensive account of all major field expeditions that have systematically surveyed sea ice and its properties. Readers will also find: A thorough introduction to ice physics and physical processes, including ice morphology and age-based structural features Practical discussions of radiometric and radar-scattering observations from sea ice, including radar backscatter and microwave emission The latest techniques for the retrieval of sea ice parameters from space-borne and airborne sensor data New chapters on sea ice thermal microwave emissions and on the impact of climate change on polar sea ice Perfect for academic researchers working on sea ice, the cryosphere, and climatology, Sea Ice: Physics and Remote Sensing will also benefit meteorologists, marine operators, and high-latitude construction engineers.

Sea Ice

Sea Ice PDF Author: David N. Thomas
Publisher: John Wiley & Sons
ISBN: 1118778383
Category : Science
Languages : en
Pages : 666

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Book Description
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.