Optical Properties of Melting First‐year Arctic Sea Ice

Optical Properties of Melting First‐year Arctic Sea Ice PDF Author: Donald K. Perovich
Publisher:
ISBN:
Category : Albedo
Languages : en
Pages : 19

Get Book Here

Book Description
The albedo and transmittance of melting, first‐year Arctic sea ice were measured during two cruises of the Impacts of Climate on the Eco‐Systems and Chemistry of the Arctic Pacific Environment (ICESCAPE) project during the summers of 2010 and 2011. Spectral measurements were made for both bare and ponded ice types at a total of 19 ice stations in the Chukchi and Beaufort Seas. These data, along with irradiance profiles taken within boreholes, laboratory measurements of the optical properties of core samples, ice physical property observations, and radiative transfer model simulations are employed to describe representative optical properties for melting first‐year Arctic sea ice. Ponded ice was found to transmit roughly 4.4 times more total energy into the ocean, relative to nearby bare ice. The ubiquitous surface‐scattering layer and drained layer present on bare, melting sea ice are responsible for its relatively high albedo and relatively low transmittance. Light transmittance through ponded ice depends on the physical thickness of the ice and the magnitude of the scattering coefficient in the ice interior. Bare ice reflects nearly three‐quarters of the incident sunlight, enhancing its resiliency to absorption by solar insolation. In contrast, ponded ice absorbs or transmits to the ocean more than three‐quarters of the incident sunlight. Characterization of the heat balance of a summertime ice cover is largely dictated by its pond coverage, and light transmittance through ponded ice shows strong contrast between first‐year and multiyear Arctic ice covers.

Optical Properties of Melting First‐year Arctic Sea Ice

Optical Properties of Melting First‐year Arctic Sea Ice PDF Author: Donald K. Perovich
Publisher:
ISBN:
Category : Albedo
Languages : en
Pages : 19

Get Book Here

Book Description
The albedo and transmittance of melting, first‐year Arctic sea ice were measured during two cruises of the Impacts of Climate on the Eco‐Systems and Chemistry of the Arctic Pacific Environment (ICESCAPE) project during the summers of 2010 and 2011. Spectral measurements were made for both bare and ponded ice types at a total of 19 ice stations in the Chukchi and Beaufort Seas. These data, along with irradiance profiles taken within boreholes, laboratory measurements of the optical properties of core samples, ice physical property observations, and radiative transfer model simulations are employed to describe representative optical properties for melting first‐year Arctic sea ice. Ponded ice was found to transmit roughly 4.4 times more total energy into the ocean, relative to nearby bare ice. The ubiquitous surface‐scattering layer and drained layer present on bare, melting sea ice are responsible for its relatively high albedo and relatively low transmittance. Light transmittance through ponded ice depends on the physical thickness of the ice and the magnitude of the scattering coefficient in the ice interior. Bare ice reflects nearly three‐quarters of the incident sunlight, enhancing its resiliency to absorption by solar insolation. In contrast, ponded ice absorbs or transmits to the ocean more than three‐quarters of the incident sunlight. Characterization of the heat balance of a summertime ice cover is largely dictated by its pond coverage, and light transmittance through ponded ice shows strong contrast between first‐year and multiyear Arctic ice covers.

The Optical and Microwave Properties of Melt Ponds Over First Year Arctic Sea Ice

The Optical and Microwave Properties of Melt Ponds Over First Year Arctic Sea Ice PDF Author: Robert B. Kirk
Publisher:
ISBN:
Category :
Languages : en
Pages : 444

Get Book Here

Book Description


The Optical Properties of Sea Ice

The Optical Properties of Sea Ice PDF Author: Donald K. Perovich
Publisher:
ISBN:
Category : Albedo
Languages : en
Pages : 34

Get Book Here

Book Description
Sea ice is a translucent material with an intricate structure and complex optical properties. Understanding the reflection, absorption, and transmission of shortwave radiation by sea ice is important to a diverse array of scientific problems, including those in ice thermodynamics and polar climatology. Radiative transfer in sea ice is a combination of absorption and scattering. Differences in the magnitude of sea ice optical properties are due primarily to differences in scattering. Spectral variations are mainly a result of absorption. Changes in such optical properties as the albedo, reflectance, transmittance, and extinction coefficient are directly related to changes in the state and structure of the ice. Physical changes that enhance scattering, such as the formation of air bubbles due to brine drainage, result in larger albedos and extinction coefficients. The albedo is quite sensitive to the surface state. If the ice has a snow cover, albedos are large. In contrast, the presence of liquid water on a bare ice surface causes a decrease in albedo, which is more pronounced at longer wavelengths. Sea-ice optical properties depend on the volume of brine and air and on how the brine and air are distributed.

Detection of Melt Ponds on Arctic Sea Ice with Optical Satellite Data

Detection of Melt Ponds on Arctic Sea Ice with Optical Satellite Data PDF Author: Anja Rösel
Publisher: Springer Science & Business Media
ISBN: 3642370330
Category : Law
Languages : en
Pages : 120

Get Book Here

Book Description
The Arctic sea ice is characterized by profound changes caused by surface melting processes and the formation of melt ponds in summer. Melt ponds contribute to the ice-albedo feedback as they reduce the surface albedo of sea ice, and hence accelerate the decay of Arctic sea ice. To quantify the melting of the entire Arctic sea ice, satellite based observations are necessary. Due to different spectral properties of snow, ice, and water, theoretically, multi-spectral optical sensors are necessary for the analysis of these distinct surface types. This study demonstrates the potential of optical sensors to detect melt ponds on Arctic sea ice. For the first time, an Arctic-wide, multi-annual melt pond data set for the years 2000-2011 has been created and analyzed.

Sea Ice

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

Get Book Here

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.

Observing and Modeling the Surface Scattering Layer of First-Year Arctic Sea Ice

Observing and Modeling the Surface Scattering Layer of First-Year Arctic Sea Ice PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 8

Get Book Here

Book Description
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.

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

Get Book Here

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 Geophysics of Sea Ice

The Geophysics of Sea Ice PDF Author: Norbert Untersteiner
Publisher: Springer
ISBN: 9781489953544
Category : Science
Languages : en
Pages : 0

Get Book Here

Book Description
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.

The Alaskan Beaufort Sea

The Alaskan Beaufort Sea PDF Author: Peter W. Barnes
Publisher: Elsevier
ISBN: 148326839X
Category : Science
Languages : en
Pages : 483

Get Book Here

Book Description
The Alaskan Beaufort Sea: Ecosystems and Environments provides an interdisciplinary view into almost all aspects of the environment, with a detailed survey of the background literature. This book focuses on the Alaskan Beaufort Shelf environment. Organized into four parts encompassing 20 chapters, this book begins with an overview of the characteristics and history of the region in which the research took place and defines the objectives of the studies program. This text then examines the subsynoptic meteorological networks along the Beaufort Sea coast and shelf. Other chapters consider the thermally generated mesoscale effects on surface winds and the orographic mesoscale effects on surface winds. This book discusses as well the phytoplankton associations and relative phytoplankton production in the area between the 20-m depth contour and the edge of the ice in summer. The final chapter deals with the characteristics of the ice cover and oil-ice interactions that will affect cleanup activities after blowout. This book is a valuable resource for scientists and conservationists.

The Optical Properties of Sea Ice

The Optical Properties of Sea Ice PDF Author: David D. Erickson
Publisher:
ISBN:
Category : Sea ice
Languages : en
Pages : 158

Get Book Here

Book Description