scholarly journals Spectral albedo of coastal landfast sea ice in Prydz Bay, Antarctica

2020 ◽  
pp. 1-11
Author(s):  
Guanghua Hao ◽  
Roberta Pirazzini ◽  
Qinghua Yang ◽  
Zhongxiang Tian ◽  
Changwei Liu
Keyword(s):  
Sea Ice ◽  
Near Infrared ◽  
Elevation Angle ◽  
Early Summer ◽  
Prydz Bay ◽  
Katabatic Wind ◽  
Surface Conditions ◽  
Zhongshan Station ◽  
Landfast Sea Ice ◽  
Two Phases

Abstract The surface spectral albedo was measured over coastal landfast sea ice in Prydz Bay (off Zhongshan Station), East Antarctica from 5 October to 26 November of 2016. The mean albedo decreased from late-spring to early-summer, mainly responding to the change in surface conditions from dry (phase I) to wet (phase II). The evolution of the albedo was strongly influenced by the surface conditions, with alternation of frequent snowfall events and katabatic wind that induce snow blowing at the surface. The two phases and day-to-day albedo variability were more pronounced in the near-infrared albedo wavelengths than in the visible ones, as the near-infrared photons are more sensitive to snow metamorphism, and to changes in the uppermost millimeters and water content of the surface. The albedo diurnal cycle during clear sky conditions was asymmetric with respect to noon, decreasing from morning to evening over full and patchy snow cover, and decreasing more rapidly in the morning over bare ice. We conclude that snow and ice metamorphism and surface melting dominated over the solar elevation angle dependency in shaping the albedo evolution. However, we realize that more detailed surface observations are needed to clarify and quantify the role of the various surface processes.

scholarly journals Modelling the thickness of landfast sea ice in Prydz Bay, East Antarctica

2015 ◽  
Vol 28 (1) ◽  
pp. 59-70 ◽  
Author(s):  
Yu Yang ◽  
Li Zhijun ◽  
Matti Leppäranta ◽  
Bin Cheng ◽  
Liqiong Shi ◽  
...  
Keyword(s):  
Sea Ice ◽  
Life Time ◽  
Prydz Bay ◽  
Ice Thickness ◽  
Minor Role ◽  
Zhongshan Station ◽  
Landfast Ice ◽  
Model Tuning ◽  
Landfast Sea Ice ◽  
A Minor

AbstractLandfast sea ice forms and remains fixed along the coast for most of its life time. In Prydz Bay, landfast ice is seasonal due to melting, mechanical breakage and drift of ice in summer. Its annual cycle of thickness and temperature was examined using a one-dimensional thermodynamic model. Model calibration was made for March 2006 to March 2007 with forcing based on the Chinese National Antarctic Research Expedition data, which consisted of in situ ice and snow observations and meteorological records at the Zhongshan Station. The observed maximum annual ice thickness was 1.74 m. The ice broke and drifted out in summer when its thickness was 0.5–1.0 m. Oceanic heat flux was estimated by tuning the model with observed ice thickness. In the growth season, it decreased from 25 W m-2 to 5 W m-2, and in summer it recovered back to 25 W m-2. Albedo was important in summer; by model tuning the estimated value was 0.6, consistent with the ice surface being bare all summer. Snow cover was thin, having a minor role. The results can be used to further our understanding of the importance of landfast ice in Antarctica for climate research and high-resolution ice–ocean modelling.

The variability of surface radiation fluxes over landfast sea ice near Zhongshan station, east Antarctica during austral spring

2017 ◽  
Vol 12 (8) ◽  
pp. 860-877 ◽  
Author(s):  
Lejiang Yu ◽  
Qinghua Yang ◽  
Mingyu Zhou ◽  
Donald H. Lenschow ◽  
Xianqiao Wang ◽  
...  
Keyword(s):  
Sea Ice ◽  
East Antarctica ◽  
Surface Radiation ◽  
Austral Spring ◽  
Zhongshan Station ◽  
Radiation Fluxes ◽  
Landfast Sea Ice

Albedo of coastal landfast sea ice in Prydz Bay, Antarctica: Observations and parameterization

2016 ◽  
Vol 33 (5) ◽  
pp. 535-543 ◽  
Author(s):  
Qinghua Yang ◽  
Jiping Liu ◽  
Matti Leppäranta ◽  
Qizhen Sun ◽  
Rongbin Li ◽  
...  
Keyword(s):  
Sea Ice ◽  
Prydz Bay ◽  
Landfast Sea Ice

Observation and thermodynamic modeling of the influence of snow cover on landfast sea ice thickness in Prydz Bay, East Antarctica

2020 ◽  
Author(s):  
Jiechen Zhao ◽  
Bin Cheng ◽  
Timo Vihma ◽  
Qinghua Yang ◽  
Fengming Hui ◽  
...  
Keyword(s):  
Sea Ice ◽  
Snow Cover ◽  
Annual Cycle ◽  
Snow Depth ◽  
Snow Accumulation ◽  
East Antarctica ◽  
Prydz Bay ◽  
Ice Thickness ◽  
Sea Ice Thickness ◽  
Landfast Sea Ice

<p>The observed snow depth and ice thickness on landfast sea ice in Prydz Bay, East Antarctica, were used to determine the role of snow in (a) the annual cycle of sea ice thickness at a fixed location (SIP) where snow usually blows away after snowfall and (b) early summer sea ice thickness within the transportation route surveys (TRS) domain farther from coast, where annual snow accumulation is substantial. The annual mean snow depth and maximum ice thickness had a negative relationship (r = −0.58, p < 0.05) at SIP, indicating a primary insulation effect of snow on ice thickness. However, in the TRS domain, this effect was negligible because snow contributes to ice thickness. A one-dimensional thermodynamic sea ice model, forced by local weather observations, reproduced the annual cycle of ice thickness at SIP well. During the freeze season, the modeled maximum difference of ice thickness using different snowfall scenarios ranged from 0.53–0.61 m. Snow cover delayed ice surface and ice bottom melting by 45 and 24 days, respectively. The modeled snow ice and superimposed ice accounted for 4–23% and 5–8% of the total maximum ice thickness on an annual basis in the case of initial ice thickness ranging from 0.05–2 m, respectively.</p>

scholarly journals Spectral albedo of snow-covered first-year and multi-year sea ice during spring melt

1995 ◽  
Vol 21 ◽  
pp. 337-342 ◽  
Author(s):  
Roger A. De Abreu ◽  
David G. Barber ◽  
Kevin Misurak ◽  
E. F. Ledrew
Keyword(s):  
Sea Ice ◽  
Near Infrared ◽  
First Year ◽  
Specific Interest ◽  
Near Surface ◽  
Surface Conditions ◽  
Ice Volume ◽  
Physical Changes ◽  
Sky Conditions ◽  
The Relationship

Surface spectral-albedo data collected over snow-covered first-year and multi-year sea ice under diffuse sky conditions during the springtime transition are examined. Of specific interest is the relationship between changes in the visible and near-infrared albedo of sea ice and concurrent changes in the geophysical characteristics of the ice volume. With the onset of melt conditions, visible and near-infrared sea-ice albedo decreased due to physical changes within the snow and ice volumes. Visible albedo was found to be sensitive to changes occurring throughout the sea-ice volume, while the near-infrared albedo appeared most influenced by near-surface conditions.

scholarly journals Annual cycle of landfast sea ice in Prydz Bay, east Antarctica

2010 ◽  
Vol 115 (C2) ◽  
Author(s):  
Ruibo Lei ◽  
Zhijun Li ◽  
Bin Cheng ◽  
Zhanhai Zhang ◽  
Petra Heil
Keyword(s):  
Sea Ice ◽  
Annual Cycle ◽  
East Antarctica ◽  
Prydz Bay ◽  
Landfast Sea Ice

scholarly journals The potential of using Landsat 7 ETM+ for the classification of sea-ice surface conditions during summer

2002 ◽  
Vol 34 ◽  
pp. 415-419 ◽  
Author(s):  
Thorsten Markus ◽  
Donald J. Cavalieri ◽  
Alvaro Ivanoff
Keyword(s):  
Sea Ice ◽  
Near Infrared ◽  
Color Image ◽  
Arctic Sea Ice ◽  
The Arctic ◽  
Surface Conditions ◽  
Melt Ponds ◽  
Wet Snow ◽  
Landsat 7 ◽  
The Individual

AbstractDuring spring and summer, the surface of the Arctic sea-ice cover undergoes rapid changes that greatly affect the surface albedo and significantly impact the further decay of the sea ice. These changes are primarily the development of a wet snow cover and the development of melt ponds. As melt ponds generally do not exceed a couple of meters in diameter, the spatial resolutions of sensors like the Advanced Very High Resolution Radiometer and Moderate Resolution Imaging Spectroradiometer are too coarse for their identification. Landsat 7, on the other hand, has a spatial resolution of 30 m (15 m for the panchromatic band) and thus offers the best chance to map the distribution of melt ponds from space. The different wavelengths (bands) from blue to near-infrared offer the potential to distinguish among different surface conditions. Landsat 7 data for the Baffin Bay region for June 2000 have been analyzed. The analysis shows that different surface conditions, such as wet snow and melt-ponded areas, have different signatures in the individual Landsat bands. Consistent with in situ albedo measurements, melt ponds show up as blueish, whereas dry and wet ice have a white to gray appearance in the Landsat true-color image. These spectral differences enable areas with high fractions of melt ponds to be distinguished.

scholarly journals Flexural and compressive strength of the landfast sea ice in the Prydz Bay, East Antarctic

2022 ◽  
Author(s):  
Qingkai Wang ◽  
Zhaoquan Li ◽  
Peng Lu ◽  
Yigang Xu ◽  
Zhijun Li
Keyword(s):  
Compressive Strength ◽  
Flexural Strength ◽  
Sea Ice ◽  
Strain Rate ◽  
Uniaxial Compressive Strength ◽  
Effective Modulus ◽  
Prydz Bay ◽  
Three Point Bending ◽  
Ice Surface ◽  
Landfast Sea Ice

Abstract. A total of 25 flexural and 55 uniaxial compressive strength tests were conducted using landfast sea ice samples collected in the Prydz Bay. Three-point bending tests were performed at ice temperatures of −12 to −3 °C with force applied vertically to original ice surface, and compressive tests were performed at −3 °C with a strain-rate level of 10−6–10−2 s−1 in the directions vertical and horizontal to ice surface. Judging from crystal structure, the ice samples were divided into congelation ice, snow ice, and a mixture of the these two. The results of congelation ice showed that the flexural strength had a decreasing trend depending on porosity rather than brine volume, based on which a mathematical equation was established to estimate flexural strength. Both flexural strength and effective modulus increased with increasing platelet spacing. The uniaxial compressive strength increased and decreased with strain rate below and above the critical regime, respectively, which is 8.0 × 10−4–1.5 × 10−3 s−1 for vertically loaded samples and 2.0 × 10−3–3.0 × 10−3 s−1 for horizontally loaded samples. A drop off in compressive strength was shown with increasing sea ice porosity. Consequently, a model was developed to depict the combined effects of porosity and strain rate on compressive strength in both ductile and brittle regimes. The mechanical strength of mixed ice was lower than congelation ice, and that of snow ice was much weaker. To provide a safe guide for the transportation of goods on landfast sea ice in the Prydz Bay, the bearing capacity of the ice cover is estimated with the lower and upper envelopes of flexural strength and effective modulus, respectively, which turned out to be a function of sea ice porosity.

scholarly journals Spectral albedo of snow-covered first-year and multi-year sea ice during spring melt

1995 ◽  
Vol 21 ◽  
pp. 337-342 ◽  
Author(s):  
Roger A. De Abreu ◽  
David G. Barber ◽  
Kevin Misurak ◽  
E. F. Ledrew
Keyword(s):  
Sea Ice ◽  
Near Infrared ◽  
First Year ◽  
Specific Interest ◽  
Near Surface ◽  
Surface Conditions ◽  
Ice Volume ◽  
Physical Changes ◽  
Sky Conditions ◽  
The Relationship

Surface spectral-albedo data collected over snow-covered first-year and multi-year sea ice under diffuse sky conditions during the springtime transition are examined. Of specific interest is the relationship between changes in the visible and near-infrared albedo of sea ice and concurrent changes in the geophysical characteristics of the ice volume. With the onset of melt conditions, visible and near-infrared sea-ice albedo decreased due to physical changes within the snow and ice volumes. Visible albedo was found to be sensitive to changes occurring throughout the sea-ice volume, while the near-infrared albedo appeared most influenced by near-surface conditions.

Sign in / Sign up

Export Citation Format

Share Document