Engineering Properties of Sea Ice

AbstractAs the continental shelves of the Arctic become important as source areas for the oil and minerals required by human society, sea ice becomes an increasing challenge to engineers. The present paper starts with a consideration of the different fields of engineering which require information on sea ice with the tasks ranging from the design of ice-breaking ships to Arctic drilling platforms and man-made ice islands. Then the structure of sea ice is described as it influences the observed variations in physical properties. Next the status of our knowledge of the physical properties important to engineering is reviewed. Properties discussed include mechanical properties (compressive, tensile, shear and flexural strengths; dynamic and static elastic moduli; Poisson’s ratio), friction and adhesion, thermal properties (specific and latent heats, thermal conductivity and diffusivity, density) and finally electromagnetic properties (dielectric permittivity and loss, resistivity). Particular attention is given to parameters such as temperature, strain-rate, brine volume, and loading direction as they affect property variations. Gaps, contradictions in the data, and inadequacies in testing techniques are pointed out. Finally suggestions are made for future research, especially for more basic laboratory studies designed to provide the data base upon which further theoretical developments as well as field studies can be built.

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Antarctic sea ice variability and trends, 1979–2010

The Cryosphere Discussions ◽

10.5194/tcd-6-931-2012 ◽

2012 ◽

Vol 6 (2) ◽

pp. 931-956 ◽

Cited By ~ 16

Author(s):

C. L. Parkinson ◽

D. J. Cavalieri

Keyword(s):

Indian Ocean ◽

Sea Ice ◽

Ross Sea ◽

Ice Cover ◽

Weddell Sea ◽

The Arctic ◽

Future Research ◽

Positive Trend ◽

Antarctic Sea Ice ◽

Ice Coverage

Abstract. In sharp contrast to the decreasing sea ice coverage of the Arctic, in the Antarctic the sea ice cover has, on average, expanded since the late 1970s. More specifically, satellite passive-microwave data for the period November 1978–December 2010 reveal an overall positive trend in ice extents of 17 100 ± 2300 km2 yr−1. Much of the increase, at 13 700 ± 1500 km2 yr−1, has occurred in the region of the Ross Sea, with lesser contributions from the Weddell Sea and Indian Ocean. One region, that of the Bellingshausen/Amundsen Seas, has, like the Arctic, instead experienced significant sea ice decreases, with an overall ice extent trend of −8200 ± 1200 km2 yr−1. When examined through the annual cycle over the 32-yr period 1979–2010, the Southern Hemisphere sea ice cover as a whole experienced positive ice extent trends in every month, ranging in magnitude from a low of 9100 ± 6300 km2 yr−1 in February to a high of 24 700 ± 10 000 km2 yr−1 in May. The Ross Sea and Indian Ocean also had positive trends in each month, while the Bellingshausen/Amundsen Seas had negative trends in each month, and the Weddell Sea and Western Pacific Ocean had a mixture of positive and negative trends. Comparing ice-area results to ice-extent results, in each case the ice-area trend has the same sign as the ice-extent trend, but differences in the magnitudes of the two trends identify regions with overall increasing ice concentrations and others with overall decreasing ice concentrations. The strong pattern of decreasing ice coverage in the Bellingshausen/Amundsen Seas region and increasing ice coverage in the Ross Sea region is suggestive of changes in atmospheric circulation. This is a key topic for future research.

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A parameter model of gas exchange for the seasonal sea ice zone

Ocean Science ◽

10.5194/os-10-17-2014 ◽

2014 ◽

Vol 10 (1) ◽

pp. 17-28 ◽

Cited By ~ 37

Author(s):

B. Loose ◽

W. R. McGillis ◽

D. Perovich ◽

C. J. Zappa ◽

P. Schlosser

Keyword(s):

Boundary Layer ◽

Gas Exchange ◽

Sea Ice ◽

Open Water ◽

Field Studies ◽

The Arctic ◽

Gas Transfer ◽

Transfer Velocity ◽

Using Data ◽

Effective Transfer

Abstract. Carbon budgets for the polar oceans require better constraint on air–sea gas exchange in the sea ice zone (SIZ). Here, we utilize advances in the theory of turbulence, mixing and air–sea flux in the ice–ocean boundary layer (IOBL) to formulate a simple model for gas exchange when the surface ocean is partially covered by sea ice. The gas transfer velocity (k) is related to shear-driven and convection-driven turbulence in the aqueous mass boundary layer, and to the mean-squared wave slope at the air–sea interface. We use the model to estimate k along the drift track of ice-tethered profilers (ITPs) in the Arctic. Individual estimates of daily-averaged k from ITP drifts ranged between 1.1 and 22 m d−1, and the fraction of open water (f) ranged from 0 to 0.83. Converted to area-weighted effective transfer velocities (keff), the minimum value of keff was 10−55 m d−1 near f = 0 with values exceeding keff = 5 m d−1 at f = 0.4. The model indicates that effects from shear and convection in the sea ice zone contribute an additional 40% to the magnitude of keff, beyond what would be predicted from an estimate of keff based solely upon a wind speed parameterization. Although the ultimate scaling relationship for gas exchange in the sea ice zone will require validation in laboratory and field studies, the basic parameter model described here demonstrates that it is feasible to formulate estimates of k based upon properties of the IOBL using data sources that presently exist.

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Antarctic sea ice variability and trends, 1979–2010

The Cryosphere ◽

10.5194/tc-6-871-2012 ◽

2012 ◽

Vol 6 (4) ◽

pp. 871-880 ◽

Cited By ~ 292

Author(s):

C. L. Parkinson ◽

D. J. Cavalieri

Keyword(s):

Indian Ocean ◽

Sea Ice ◽

Ross Sea ◽

Ice Cover ◽

Weddell Sea ◽

The Arctic ◽

Future Research ◽

Positive Trend ◽

Antarctic Sea Ice ◽

Ice Coverage

Abstract. In sharp contrast to the decreasing sea ice coverage of the Arctic, in the Antarctic the sea ice cover has, on average, expanded since the late 1970s. More specifically, satellite passive-microwave data for the period November 1978–December 2010 reveal an overall positive trend in ice extents of 17 100 ± 2300 km2 yr−1. Much of the increase, at 13 700 ± 1500 km2 yr−1, has occurred in the region of the Ross Sea, with lesser contributions from the Weddell Sea and Indian Ocean. One region, that of the Bellingshausen/Amundsen Seas, has (like the Arctic) instead experienced significant sea ice decreases, with an overall ice extent trend of −8200 ± 1200 km2 yr−1. When examined through the annual cycle over the 32-yr period 1979–2010, the Southern Hemisphere sea ice cover as a whole experienced positive ice extent trends in every month, ranging in magnitude from a low of 9100 ± 6300 km2 yr−1 in February to a high of 24 700 ± 10 000 km2 yr−1 in May. The Ross Sea and Indian Ocean also had positive trends in each month, while the Bellingshausen/Amundsen Seas had negative trends in each month, and the Weddell Sea and western Pacific Ocean had a mixture of positive and negative trends. Comparing ice-area results to ice-extent results, in each case the ice-area trend has the same sign as the ice-extent trend, but the magnitudes of the two trends differ, and in some cases these differences allow inferences about the corresponding changes in sea ice concentrations. The strong pattern of decreasing ice coverage in the Bellingshausen/Amundsen Seas region and increasing ice coverage in the Ross Sea region is suggestive of changes in atmospheric circulation. This is a key topic for future research.

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Observations on the Physical Properties of Sea-Ice at Hopedale, Labrador

ARCTIC ◽

10.14430/arctic3740 ◽

1958 ◽

Vol 11 (3) ◽

pp. 134 ◽

Cited By ~ 54

Author(s):

Wilford F. Weeks ◽

Owen S. Lee

Keyword(s):

Sea Ice ◽

Physical Properties ◽

Air Force ◽

Sea Water ◽

Field Studies ◽

Water Levels ◽

Cambridge Research ◽

Freezing Period ◽

Before And After ◽

General Physical

Preliminary results are reported of field studies 1955-56 by the U.S. Air Force Cambridge Research Center, the Hydrographic Office and SIPRE on the general physical properties of sea ice; methods of measurement are described. Characteristics of sea water during the freezing period are outlined: formation, structure, and salinity of the initial ice cover, formation and characteristics of infiltrated snow-ice, growth of the ice and influencing factors, density of the ice at various periods, and crack formation are discussed. Data on the salinity of sea ice formed during during wave action and that of sheet-ice, hourly averages of air and ice temperatures at various levels, snow and slush density and thickness, observed slush levels and theoretical water levels are shown. Salinity of ice before and after the slush layer froze, and that of deteriorating ice , salinity of ice vs. ice thickness, thickness of ice versus degree-days, the density of the ice, and measured ice densities vs. theoretical density of air-free sea ice at -15 C are figured and discussed. The orientation of sea ice c-axes and of infiltrated snow-ice c-axes are diagrammed.--From SIPRE.

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Physical Properties of Summer Sea Ice in the Pacific Sector of the Arctic During 2008–2018

Journal of Geophysical Research Oceans ◽

10.1029/2020jc016371 ◽

2020 ◽

Vol 125 (9) ◽

Author(s):

Q. Wang ◽

P. Lu ◽

M. Leppäranta ◽

B. Cheng ◽

G. Zhang ◽

...

Keyword(s):

Sea Ice ◽

Physical Properties ◽

The Arctic ◽

The Pacific

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A REVIEW ON THE ENGINEERING PROPERTIES OF SOYBEAN TO SUPPORT THE TOFU AGRO-INDUSTRIAL MACHINERY DEVELOPMENT AND IMPORTANT HIGHLIGHTS

AGROINTEK ◽

10.21107/agrointek.v15i3.10496 ◽

2021 ◽

Vol 15 (3) ◽

pp. 921-931

Author(s):

Agustami Sitorus ◽

Devianti Devianti ◽

Ramayanty Bulan

Keyword(s):

Mechanical Properties ◽

Moisture Content ◽

Physical Properties ◽

Angle Of Repose ◽

Engineering Properties ◽

Future Research ◽

Aerodynamic Properties ◽

Study Results ◽

Scientific Papers ◽

Soybean Processing

The physical and mechanical properties of the material to be processed are fundamental and continue to be a challenge for researchers to design a machine appropriately. Studies of the soybean engineering properties have not been widely highlighted and reviewed. This makes researchers and engineers of soybean processing machines still have to search through experimentation or read deeply through scientific papers before applying it. Therefore, this paper presents highlights and reviews of studies related to the measurement and modelling of soybean engineering properties. The objective is to study methodologies uses and identify future research directions to get a result in more accuracy. Several papers are searched from various search engines for scientific articles that are available online. Some keywords and a combination of keywords used in the search process are “physical properties”, “mechanical properties”, “soybean grains” and “moisture-dependent”. The results show that ten scientific papers are strictly related to the measurement and modelling of the engineering properties of soybean. In general, the documents found were in the period 1993 to 2012. The research paper investigated the engineering properties of soybean in the moisture content ranges from 6.7% (d.b.) to 49.7% (d.b.). The widely studied physical properties are diameter, surface area, roundness, the weight of 1000 soybeans, bulk density, and true density associated with moisture content. Mechanical parameters investigated include friction coefficient, angle of repose, terminal velocity, angle of internal friction, rupture force, and rupture energy. On the one hand, some of the engineering properties of soybeans that have not yet been discovered are thermal, optical, and aerodynamic properties. On the other hand, the effect of soaking and blanching on changes in the engineering properties of soybean (physical, mechanical, thermal, optical, and aerodynamic) has not been done in-depth. Besides that, most of the soybean processing agro-industry requires engineering properties of soybean to be able to design their machines more precisely. One of the agro-industries that need data on the study results of the nature of engineering with these treatments is the tofu processing industry.

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Laboratory Experiments on Crystal Orientation in NaCl Ice

Annals of Glaciology ◽

10.3189/s0260305500005413 ◽

1983 ◽

Vol 4 ◽

pp. 163-169 ◽

Cited By ~ 8

Author(s):

Patricia J. Langhorne

Keyword(s):

Sea Ice ◽

Laboratory Experiments ◽

Fluid Motion ◽

Preferred Orientation ◽

The Arctic ◽

Electromagnetic Properties ◽

Relative Growth ◽

Relative Growth Rates ◽

Polar Research Institute ◽

Oceanic Currents

Over extensive areas of the Arctic and Antarctic, the c-axes of the grains in a sea-ice sheet develop a preferred orientation in a particular direction in the Horizontal plane, causing the physical and electromagnetic properties of the material to be anisotropic. A number of mechanisms have been proposed for this alignment, the more likely including the tilting of floes, horizontal temperature gradient, horizontal deviatone stresses, and oceanic currents. Laboratory experiments have been performed at the Scott Polar Research Institute to distinguish the effects of these mechanisms on the fabric of sea ice. Ho correlation was found between the development of the preferred orientation of c-axes and any of the first three mechanisms. However, in the presence of a current, the strength of the alignment increases rapidly with depth in the ice, the mean c-axis direction coinciding with the current direction. A significant reduction in alignment was produced when the flow was reduced to zero. In addition, upstream deflection of the columnar axis was observed in flowing brine. These results indicate the importance of fluid motion in controlling the rate of transport of solute from the interface and hence the relative growth rates of grains of different orientations.

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Trend analysis of aerosol particle physical properties at Villum Research Station, Northern Greenland

10.5194/egusphere-egu21-12767 ◽

2021 ◽

Author(s):

Jakob Pernov ◽

Henrik Skov ◽

Daniel Thomas ◽

Andreas Massling

Keyword(s):

Sea Ice ◽

Physical Properties ◽

The Arctic ◽

Anthropogenic Emissions ◽

Research Station ◽

Sea Ice Extent ◽

Accumulation Mode ◽

Cloud Properties ◽

Arctic Aerosol ◽

Increasing Trends

IntroductionThe Arctic region is particularly sensitive to global climate change, experiencing warming at twice the rate of the global average. Anthropogenic pollution (e.g. aerosols, black carbon, ozone, and greenhouse gases), which to a large extent originates from the mid-latitudes, is suspected to be partly responsible for this warming. Atmospheric aerosols can alter the planetary radiation balance directly through scattering and absorption and indirectly through modification of cloud properties. These interactions depend on aerosol physicochemical properties. The Arctic cryosphere and atmosphere has undergone significant changes in recent decades, accompanied by reductions in anthropogenic emissions, especially in Europe and North America. These changes have important ramifications for the ambient Arctic aerosol. Understanding the direction and magnitude of recent changes in the Arctic aerosol population is key to elucidating the implications for the changing Arctic, although this remains a scientific challenge. Here we report recent trends for aerosol particle physical properties, which will aid in this understanding of the changing Arctic.Measurement Site & MethodsAll measurements were obtained at Villum Research Station (Villum, N 81o36&#8217; W 16o39&#8217; 24 m a.s.l) in northeastern Greenland. Particle number size distributions (PNSD) were measured using a Scanning Mobility Particle Sizer (SMPS) from 2010&#8211;2018.We have utilized mode fitting on daily averaged PNSDs to characterize three distinct modes (Nucleation, Aitken, and Accumulation) along with geometric mean diameters (GMD) and number concentrations (PN) for each mode.The trends in these parameters were identified and quantified using the Mann-Kendal test and Theil Sen slope on the 90th % confidence interval. Trends in different months were analyzed using daily modal parameters.ResultsStatistically significant (s.s.) decreasing trends were detected for the Nucleation and Aitken modes GMDs in the winter, spring, and summer, with the only s.s. increasing trends occurring in the autumn. The Accumulation mode GMD showed a s.s. decrease in the spring and s.s. increase in the summer. For the PN of each mode, large s.s. increasing trends were detected for Nucleation and Aitken mode PN in the spring and summer. The Accumulation mode PN showed a small s.s. increase in the summer and a large s.s. decrease in the autumn.&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160; These results show that ultrafine modes (Nucleation and Aitken) are decreasing in diameter while simultaneously increasing in number concentration. These trends are most likely related to changes in sea ice extent, as previous research has indicated a negative correlation between new particle formation and sea ice extent. The decrease in Accumulation mode GMD in spring (during the peak of the Arctic Haze) is possibly related to decreases in anthropogenic emissions, while the increase PN during summer could signal an increase in primary biogenic aerosol emissions from the ocean surface. The large decrease in Accumulation mode PN during autumn requires further investigation.&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160; This work will help confirm trends of other aerosol components observed at other High Arctic sites and can offer insight into the climatic implications (i.e., radiative balance and cloud properties) for a future Arctic climate.

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Litter and Microplastics: Environmental monitoring in the Arctic

10.5194/egusphere-egu21-16515 ◽

2021 ◽

Author(s):

Jan Rene Larsen ◽

Jennifer Provencher ◽

Eivind Farmen

Keyword(s):

Sea Ice ◽

Monitoring Program ◽

The Arctic ◽

Expert Group ◽

Plastic Pollution ◽

Arctic Council ◽

Arctic Ecosystem ◽

The Status ◽

New Research ◽

Climate Crisis

While the Arctic Ecosystem is already stressed by the effects of the climate crisis, another threat is emerging: plastics. Plastic pollution has become an environmental issue of the highest concern world-wide, and the plastic pollution tide is also rising in the Arctic.The pristine Arctic environments, far from most of the world&#8217;s major industrial areas, are becoming laden with plastic pollution. Microplastics have been found in Arctic snow, sea-ice, seawater, in sediments collected on the ocean floor, and on Arctic beaches. Larger pieces of plastic debris are also making their way into the food webs as whales, fish and birds can ingest them or get entangled in them. Climate change is expected to exacerbate the amount of debris in the Arctic, via melting sea-ice and increasing contributions from human activities.The Artic Monitoring and Assessment Programme (AMAP) is a Working Group of the Arctic Council. AMAP has a mandate to monitor and assess the status and trends of contaminants in the Arctic. In the Spring of 2019, AMAP decided to step up its efforts on the plastic issue and established an Expert Group on microplastics and litter with experts from Artic Council States and Observer countries.The Expert Group has developed a comprehensive monitoring plan and technical guidelines for monitoring microplastics and litter in the Arctic. It will be the first time that all parts of the Arctic ecosystem are examined for traces of this type of pollution. The Expert Group aims to:<ul><li>Design a program for the monitoring of microplastics and litter in the Arctic environment.</li> <li>Develop necessary guidelines supporting the monitoring program.</li> <li>Formulate recommendations and identify areas where new research and development is necessary from an Arctic perspective.</li> </ul>

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