Ice action on Nanisivik wharf, Strathcona Sound, N.W.T., winter 1978–1979

R. M. W. Frederking

doi:10.1139/l80-064

Characteristics of Sea-ice thickness and Snow-depth distributions of the Summer landfast ice in Lützow-Holm Bay, East Antarctica

Annals of Glaciology ◽

10.3189/172756406781811240 ◽

2006 ◽

Vol 44 ◽

pp. 281-287 ◽

Cited By ~ 9

Author(s):

Shotaro Uto ◽

Haruhito Shimoda ◽

Shuki Ushio

Keyword(s):

Sea Ice ◽

Interannual Variability ◽

Snow Depth ◽

East Antarctica ◽

Ice Thickness ◽

First Year ◽

Total Thickness ◽

Sea Ice Thickness ◽

Landfast Ice ◽

Northeasterly Wind

AbstractSea-ice observations have been conducted on board icebreaker shirase as a part of the Scientific programs of the Japanese Antarctic Research Expedition. We Summarize these to investigate Spatial and interannual variability of ice thickness and Snow depth of the Summer landfast ice in Lützow-Holm Bay, East Antarctica. Electromagnetic–inductive observations, which have been conducted Since 2000, provide total thickness distributions with high Spatial resolution. A clear discontinuity, which Separates thin first-year ice from thick multi-year ice, was observed in the total thickness distributions in two voyages. Comparison with Satellite images revealed that Such phenomena reflected the past breakup of the landfast ice. Within 20–30km from the Shore, total thickness as well as Snow depth decrease toward the Shore. This is due to the Snowdrift by the Strong northeasterly wind. Video observations of Sea-ice thickness and Snow depth were conducted on 11 voyages Since December 1987. Probability density functions derived from total thickness distributions in each year are categorized into three types: a thin-ice, thick-ice and intermediate type. Such interannual variability primarily depends on the extent and duration of the Successive break-up events.

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A Field Study of Brine Drainage and Oil Entrainment in First-Year Sea Ice

Journal of Glaciology ◽

10.3189/s0022143000014477 ◽

1979 ◽

Vol 22 (88) ◽

pp. 473-502 ◽

Cited By ~ 5

Author(s):

Seelye Martin

Keyword(s):

Sea Ice ◽

Growth And Development ◽

Salt Transport ◽

First Year ◽

Field Observations ◽

Melt Pond ◽

Ice Surface ◽

Melt Ponds ◽

Brine Channel ◽

Horizontal Layers

AbstractFrom field observations this paper describes the growth and development of first-year sea ice and its interaction with petroleum. In particular, when sea ice initially forms, there is an upward salt transport so that the ice surface has a highly saline layer, regardless of whether the initial ice is frazil, columnar, or slush ice. When the ice warms in the spring, because of the eutectic condition, the surface salt liquifies and drains through the ice, leading to the formation of top-to-bottom brine channels and void spaces in the upper part of the ice. If oil is released beneath winter ice, then the oil becomes entrained in thin lenses within the ice. In the spring, this oil flows up to the surface through the newly-opened brine channels and distributes itself within the brine-channel feeder systems, on the ice surface, and in horizontal layers in the upper part of the ice. The paper shows that these layers probably form from the interaction of the brine drainage with the percolation of melt water from surface snow down into the ice and the rise of the oil from below. Finally in the summer, the oil on the surface leads to melt-pond formation. The solar energy absorbed by the oil on the surface of these melt ponds eventually causes the melt pond to melt through the ice, and the oil is again released into the ocean.

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Arctic sea-ice albedo derived from RGPS-based ice-thickness estimates

Annals of Glaciology ◽

10.3189/172756401781818103 ◽

2001 ◽

Vol 33 ◽

pp. 225-229 ◽

Cited By ~ 8

Author(s):

R.W. Lindsay

Keyword(s):

Sea Ice ◽

Empirical Relationship ◽

Early Spring ◽

Snow Accumulation ◽

Arctic Sea Ice ◽

Ice Thickness ◽

First Year ◽

Large Set ◽

Radar Images ◽

Arctic Sea

AbstractThe RADARSAT geophysical processor system (RGPS) uses sequential synthetic aperture radar images of Arctic sea ice taken every 3 days to track a large set of Lagrangian points over the winter and spring seasons. The points are the vertices of cells, which are initially square and 10 km on a side, and the changes in the area of these cells due to opening and closing of the ice are used to estimate the fractional area of a set of first-year ice categories. The thickness of each category is estimated by the RGPS from an empirical relationship between ice thickness and the freezing degree-days since the formation of the ice. With a parameterization of the albedo based on the ice thickness, the albedo may be estimated from the first-year ice distribution. We compute the albedo for the first spring processed by the RGPS, the early spring of 1997. The data include most of the Beaufort and Chukchi Seas. We find that the mean albedo is 0.79 with a standard deviation of 0.04, with lower albedo values near the edge of the perennial ice zone. The biggest source of error is likely the assumed rate of snow accumulation on new ice.

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A sea-ice thickness retrieval model for 1.4 GHz radiometry and application to airborne measurements over low salinity sea-ice

The Cryosphere ◽

10.5194/tc-4-583-2010 ◽

2010 ◽

Vol 4 (4) ◽

pp. 583-592 ◽

Cited By ~ 59

Author(s):

L. Kaleschke ◽

N. Maaß ◽

C. Haas ◽

S. Hendricks ◽

G. Heygster ◽

...

Keyword(s):

Sea Ice ◽

Brightness Temperature ◽

Ice Thickness ◽

First Year ◽

Sea Ice Thickness ◽

Model Calculations ◽

Airborne Measurements ◽

Low Salinity ◽

Research Aircraft ◽

L Band

Abstract. In preparation for the European Space Agency's (ESA) Soil Moisture and Ocean Salinity (SMOS) mission, we investigated the potential of L-band (1.4 GHz) radiometry to measure sea-ice thickness. Sea-ice brightness temperature was measured at 1.4 GHz and ice thickness was measured along nearly coincident flight tracks during the SMOS Sea-Ice campaign in the Bay of Bothnia in March 2007. A research aircraft was equipped with the L-band Radiometer EMIRAD and coordinated with helicopter based electromagnetic induction (EM) ice thickness measurements. We developed a three layer (ocean-ice-atmosphere) dielectric slab model for the calculation of ice thickness from brightness temperature. The dielectric properties depend on the relative brine volume which is a function of the bulk ice salinity and temperature. The model calculations suggest a thickness sensitivity of up to 1.5 m for low-salinity (multi-year or brackish) sea-ice. For Arctic first year ice the modelled thickness sensitivity is less than half a meter. It reduces to a few centimeters for temperatures approaching the melting point. The campaign was conducted under unfavorable melting conditions and the spatial overlap between the L-band and EM-measurements was relatively small. Despite these disadvantageous conditions we demonstrate the possibility to measure the sea-ice thickness with the certain limitation up to 1.5 m. The ice thickness derived from SMOS measurements would be complementary to ESA's CryoSat-2 mission in terms of the error characteristics and the spatiotemporal coverage. The relative error for the SMOS ice thickness retrieval is expected to be not less than about 20%.

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Characterizing Arctic sea ice topography using high-resolution IceBridge data

The Cryosphere ◽

10.5194/tc-10-1161-2016 ◽

2016 ◽

Vol 10 (3) ◽

pp. 1161-1179 ◽

Cited By ~ 15

Author(s):

Alek A. Petty ◽

Michel C. Tsamados ◽

Nathan T. Kurtz ◽

Sinead L. Farrell ◽

Thomas Newman ◽

...

Keyword(s):

High Resolution ◽

Sea Ice ◽

Arctic Sea Ice ◽

Surface Feature ◽

Ice Thickness ◽

First Year ◽

Data Set ◽

Surface Features ◽

Developed Surface ◽

Arctic Sea

Abstract. We present an analysis of Arctic sea ice topography using high-resolution, three-dimensional surface elevation data from the Airborne Topographic Mapper, flown as part of NASA's Operation IceBridge mission. Surface features in the sea ice cover are detected using a newly developed surface feature picking algorithm. We derive information regarding the height, volume and geometry of surface features from 2009 to 2014 within the Beaufort/Chukchi and Central Arctic regions. The results are delineated by ice type to estimate the topographic variability across first-year and multi-year ice regimes. The results demonstrate that Arctic sea ice topography exhibits significant spatial variability, mainly driven by the increased surface feature height and volume (per unit area) of the multi-year ice that dominates the Central Arctic region. The multi-year ice topography exhibits greater interannual variability compared to the first-year ice regimes, which dominates the total ice topography variability across both regions. The ice topography also shows a clear coastal dependency, with the feature height and volume increasing as a function of proximity to the nearest coastline, especially north of Greenland and the Canadian Archipelago. A strong correlation between ice topography and ice thickness (from the IceBridge sea ice product) is found, using a square-root relationship. The results allude to the importance of ice deformation variability in the total sea ice mass balance, and provide crucial information regarding the tail of the ice thickness distribution across the western Arctic. Future research priorities associated with this new data set are presented and discussed, especially in relation to calculations of atmospheric form drag.

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Early winter ice and snow thickness distribution, ice structure and development of the western Ross Sea pack ice between the ice edge and the Ross Ice Shelf

Antarctic Science ◽

10.1017/s0954102097000242 ◽

1997 ◽

Vol 9 (2) ◽

pp. 188-200 ◽

Cited By ~ 50

Author(s):

Martin O. Jeffries ◽

Ute Adolphs

Keyword(s):

Sea Ice ◽

Layer Thickness ◽

Ross Sea ◽

Ice Thickness ◽

First Year ◽

Ross Ice Shelf ◽

Antarctic Sea Ice ◽

Pack Ice ◽

Ice Edge ◽

Snow And Ice

A study of early winter first-year sea ice conditions and development in the western Ross Sea in May and June 1995 included measurements of snow and ice thickness, freeboard, ice core structure and stable isotopic composition. These variables showed strong spatial variability between the Ross Ice Shelf and the ice edge 1400 km to the north, and indicate that the development of the Ross Sea pack ice is quite different from that observed in other Antarctic sea ice zones. The thinnest snow and ice occurred in a 200 km wide coastal zone. The thickest snow and ice were observed in a continental shelf zone 200–600 km from the coast where the average ice thickness (0.8 m) determined by drilling is as thick as first-year sea ice later in winter elsewhere in Antarctica. A zone of moderate snow and ice thickness occurred on the deep ocean from 600 km to the ice edge at 1400 km. Thermodynamic thickening of the ice in the inner pack ice, <800 km from the coast, was dominated by congelation ice growth, which occurred in a greater amount (65%) and in thicker layers (mean: 20 cm) than was observed in the outer pack ice >800 km from the coast (amount: 22%; mean layer thickness: 12 cm) and elsewhere in the Antarctic pack ice. The preponderance of congelation ice in the inner pack ice might be due to a low oceanic heat flux on the Ross Sea continental shelf, and a colder, less stormy environment which favours the more frequent and prolonged calm conditions necessary for significant congelation ice growth. In the outer pack ice, thermodynamic thickening occurred mainly by snow ice formation (mean layer thickness: 20 cm) while dynamic processes, i.e., rafting and ridging, caused the thickening of frazil ice and columnar ice (mean layer thickness: 14 cm and 12 cm respectively). A greater amount of snow ice (37%) occurred in the outer pack ice than in the inner pack ice (15%), and both values indicate that in the Ross Sea, unlike other Antarctic sea ice zones, there can be significant seawater flooding of the snow/ice interface and snow ice formation before midwinter.

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Modeling the seasonal evolution of the Arctic sea ice floe size distribution

Elem Sci Anth ◽

10.12952/journal.elementa.000126 ◽

2016 ◽

Vol 4 ◽

Cited By ~ 9

Author(s):

Jinlun Zhang ◽

Harry Stern ◽

Byongjun Hwang ◽

Axel Schweiger ◽

Michael Steele ◽

...

Keyword(s):

Sea Ice ◽

Size Distribution ◽

Power Law ◽

Annual Cycle ◽

Arctic Sea Ice ◽

The Arctic ◽

Ice Thickness ◽

First Year ◽

Seasonal Evolution ◽

Marginal Ice Zone

Abstract To better simulate the seasonal evolution of sea ice in the Arctic, with particular attention to the marginal ice zone, a sea ice model of the distribution of ice thickness, floe size, and enthalpy was implemented into the Pan-arctic Ice–Ocean Modeling and Assimilation System (PIOMAS). Theories on floe size distribution (FSD) and ice thickness distribution (ITD) were coupled in order to explicitly simulate multicategory FSD and ITD distributions simultaneously. The expanded PIOMAS was then used to estimate the seasonal evolution of the Arctic FSD in 2014 when FSD observations are available for model calibration and validation. Results indicate that the simulated FSD, commonly described equivalently as cumulative floe number distribution (CFND), generally follows a power law across space and time and agrees with the CFND observations derived from TerraSAR-X satellite images. The simulated power-law exponents also correlate with those derived using MODIS images, with a low mean bias of –2%. In the marginal ice zone, the modeled CFND shows a large number of small floes in winter because of stronger winds acting on thin, weak first-year ice in the ice edge region. In mid-spring and summer, the CFND resembles an upper truncated power law, with the largest floes mostly broken into smaller ones; however, the number of small floes is lower than in winter because floes of small sizes or first-year ice are easily melted away. In the ice pack interior there are fewer floes in late fall and winter than in summer because many of the floes are “welded” together into larger floes in freezing conditions, leading to a relatively flat CFND with low power-law exponents. The simulated mean floe size averaged over all ice-covered areas shows a clear annual cycle, large in winter and smaller in summer. However, there is no obvious annual cycle of mean floe size averaged over the marginal ice zone. The incorporation of FSD into PIOMAS results in reduced ice thickness, mainly in the marginal ice zone, which improves the simulation of ice extent and yields an earlier ice retreat.

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North Atlantic warming and declining volume of arctic sea ice

The Cryosphere Discussions ◽

10.5194/tcd-7-245-2013 ◽

2013 ◽

Vol 7 (1) ◽

pp. 245-265 ◽

Cited By ~ 28

Author(s):

V. A. Alexeev ◽

V. V. Ivanov ◽

R. Kwok ◽

L. H. Smedsrud

Keyword(s):

Sea Ice ◽

Large Scale ◽

Atlantic Water ◽

Arctic Sea Ice ◽

The Arctic ◽

Ice Thickness ◽

First Year ◽

Pacific Water ◽

Svalbard Archipelago ◽

Arctic Sea

Abstract. Long-term thinning of arctic sea ice over the last few decades has resulted in significant declines in the coverage of thick multi-year ice accompanied by a proportional increase in thinner first-year ice. This change is often attributed to changes in the arctic atmosphere, both in composition and large-scale circulation, and greater inflow of warmer Pacific water through the Bering Strait. The Atlantic Water (AW) entering the Arctic through Fram Strait has often been considered less important because of strong stratification in the Arctic Ocean and the deeper location of AW compared to Pacific water. In our combined examination of oceanographic measurements and satellite observations of ice concentration and thickness, we find evidence that AW has a direct impact on the thinning of arctic sea ice downstream of Svalbard Archipelago. The affected area extends as far as Severnaya Zemlya Archipelago. The imprints of AW appear as local minima in sea ice thickness; ice thickness is significantly less than that expected of first-year ice. Our lower-end conservative estimates indicate that the recent AW warming episode could have contributed up to 150–200 km3 of sea ice melt per year, which would constitute about 20% of the total 900 km3yr−1 negative trend in sea ice volume since 2004.

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Stages of sea ice development in the Laptev sea

Arctic and Antarctic Research ◽

10.30758/0555-2648-2017-0-4-5-15 ◽

2017 ◽

pp. 5-15 ◽

Cited By ~ 1

Author(s):

S. V. Hotchenkov

Keyword(s):

Sea Ice ◽

Ice Cover ◽

Ice Thickness ◽

Winter Period ◽

First Year ◽

Laptev Sea ◽

Partial Concentration ◽

Fast Ice ◽

Drifting Ice ◽

The Laptev Sea

Variability of the stages of sea ice development in the Laptev Sea is assessed with 10-days periodicity for the autumn — winter period on a basis of AARI digital ice charts for 1997–2017. Difference in formation of the stages of ice development (ice thickness) was revealed between the drifting and fast ice, which is manifested in an earlier appearance of the first-year ice for the fast ice area and in its partial concentration. On average, the ice cover of the Laptev Sea is by 60 % composed of thick first-year ice, most of which is formed within the fast ice area — 38%, while the area of drifting ice is 1,5 times larger.

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