Physical properties, spectral reflectance and thickness development of first year fast ice in Kongsfjorden, Svalbard

1999 ◽  
Vol 18 (2) ◽  
pp. 275-282 ◽  
Author(s):  
Sebastian Gerland ◽  
Jan-Gunnar Winther ◽  
Jon Børre Ørbæk ◽  
Boris V. Ivanov
1999 ◽  
Vol 18 (2) ◽  
pp. 275-282 ◽  
Author(s):  
Sebastian Gerland ◽  
Jan-Gunnar Winther ◽  
Jon Børre Ørbæk ◽  
Boris V. Ivanov

1994 ◽  
Vol 20 ◽  
pp. 61-66 ◽  
Author(s):  
A.L. Veazey ◽  
M.O. Jeffries ◽  
K. Morris

The small-scale variability of physical properties and structural characteristics of multiple pairs of fast-ice cores obtained during the austral summer of 1991-92 at two Antarctic sites, McMurdo Sound (MCM) and Pine Island Bay (PIB), are examined and discussed with respect to the growth and decay of the sea ice. The ice at the MCM site was thicker than that at the PIB site and was covered by a somewhat thinner snowpack. While mean salinity and temperature of the ice at the two sites were similar, small-scale variations in both salinity and temperature were greater at PIB than at MCM. The ice sheet at MCM was a two-layer medium consisting of congelation ice overlying platelet ice. The ice from the PIB site, however, was composed of mainly frazil ice and layers of congelation ice with occasional thin layers of snow-ice at the surface of the cores. Crystal sub-structure measurements, c-axis orientation and brine-layer spacing from the MCM cores revealed that the congelation ice had moderately aligned, horizontally oriented c axes, suggesting that east-west currents off the southwest tip of Hut Point Peninsula control crystal-growth orientation.d others: Variability of physical and structural characteristics of Antarctic fast ice


2019 ◽  
Vol 32 (15) ◽  
pp. 4805-4828 ◽  
Author(s):  
Jake J. Gristey ◽  
J. Christine Chiu ◽  
Robert J. Gurney ◽  
Keith P. Shine ◽  
Stephan Havemann ◽  
...  

AbstractThe spectrum of reflected solar radiation emerging at the top of the atmosphere is rich with Earth system information. To identify spectral signatures in the reflected solar radiation and directly relate them to the underlying physical properties controlling their structure, over 90 000 solar reflectance spectra are computed over West Africa in 2010 using a fast radiation code employing the spectral characteristics of the Scanning Imaging Absorption Spectrometer for Atmospheric Chartography (SCIAMACHY). Cluster analysis applied to the computed spectra reveals spectral signatures related to distinct surface properties, and cloud regimes distinguished by their spectral shortwave cloud radiative effect (SWCRE). The cloud regimes exhibit a diverse variety of mean broadband SWCREs, and offer an alternative approach to define cloud type for SWCRE applications that does not require any prior assumptions. The direct link between spectral signatures and distinct physical properties extracted from clustering remains robust between spatial scales of 1, 20, and 240 km, and presents an excellent opportunity to understand the underlying properties controlling real spectral reflectance observations. Observed SCIAMACHY spectra are assigned to the calculated spectral clusters, showing that cloud regimes are most frequent during the active West African monsoon season of June–October in 2010, and all cloud regimes have a higher frequency of occurrence during the active monsoon season of 2003 compared with the inactive monsoon season of 2004. Overall, the distinct underlying physical properties controlling spectral signatures show great promise for monitoring evolution of the Earth system directly from solar spectral reflectance observations.


Author(s):  
S. V. Hotchenkov

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.


1981 ◽  
Vol 27 (96) ◽  
pp. 315-330 ◽  
Author(s):  
M. Nakawo ◽  
N. K Sinha

AbstractThis paper describes the growth of sea ice and the salinity profiles observed in Eclipse Sound near Pond Inlet, Baffin Island, Canada, during the winter of 1977–78. A numerical method of calculation has been developed to incorporate the variations in snow conditions and physical properties of ice and snow during the growth season. It is shown that the growth rate can be predicted reasonably well. It is also shown that the vertical salinity profile in the ice towards the end of the season, provides a record of previous climatological conditions. A dependence has been shown between the predicted growth rate and the measured salinity.


1994 ◽  
Vol 20 ◽  
pp. 61-66 ◽  
Author(s):  
A.L. Veazey ◽  
M.O. Jeffries ◽  
K. Morris

The small-scale variability of physical properties and structural characteristics of multiple pairs of fast-ice cores obtained during the austral summer of 1991-92 at two Antarctic sites, McMurdo Sound (MCM) and Pine Island Bay (PIB), are examined and discussed with respect to the growth and decay of the sea ice. The ice at the MCM site was thicker than that at the PIB site and was covered by a somewhat thinner snowpack. While mean salinity and temperature of the ice at the two sites were similar, small-scale variations in both salinity and temperature were greater at PIB than at MCM. The ice sheet at MCM was a two-layer medium consisting of congelation ice overlying platelet ice. The ice from the PIB site, however, was composed of mainly frazil ice and layers of congelation ice with occasional thin layers of snow-ice at the surface of the cores. Crystal sub-structure measurements, c-axis orientation and brine-layer spacing from the MCM cores revealed that the congelation ice had moderately aligned, horizontally oriented c axes, suggesting that east-west currents off the southwest tip of Hut Point Peninsula control crystal-growth orientation.d others: Variability of physical and structural characteristics of Antarctic fast ice


2006 ◽  
Vol 44 ◽  
pp. 154-162 ◽  
Author(s):  
M. Johnston

AbstractMeasurements made on first-year ice in the Arctic and sub-Arctic are used to show that ice from both regions decays in a similar manner during the spring/summer melt season. One notable difference is that melt-induced changes in sub-Arctic Labrador occur about 2 months earlier than in the Arctic. In both regions, the temperature and strength of the ice change gradually over the season, whereas the bulk salinity and thickness of the ice do not change substantially until later in the season, when the ice becomes isothermal at a temperature of –1.8˚C. Results show that the seasonal decrease in the strength of first-year sea ice and the temperature-induced increase in brine volume are correlated. Once the ice is devoid of salt in late summer, the air volume continues to increase but has minimal effect on the ice strength.


2020 ◽  
Vol 6 (10) ◽  
pp. 135-142
Author(s):  
S. Gurbanov

The article is devoted to the study of the regularity of changes in the specific surface of soil under the influence of agromeliorative measures, mainly irrigation and agrotechnical works carried out in the gray-brown soils of the Absheron Peninsula of Azerbaijan. Based on four years of experiments, it was determined that changes occur in the specific surface of the soil in the plowed layer as a result of the agromeliorative measures taken. Thus, a decrease in the specific surface area was observed in the 0–20 cm soil layer, and an increase in the specific surface area was observed in the 20–40 cm soil layer. In the first year of the experiments, the value of the average specific surface in the 0–20 cm soil layer was 3,098–3,988 cm2/g, and in the 20–40 cm soil layer it was 1,056–3,567 cm2 /g. However, after four years, the value of the special surface was 1,949–3,340 cm2/g in the 0–20 cm soil layer and 3,290–5,023 cm2/g in the 20–40 cm layer. The increase in the specific surface area in the lower layers of the soil is due to the gradual washing of dust, silt and colloidal particles from the plow layer to the lower layers. The reduction of the specific surface in the topsoil leads to the degradation of the topsoil, the deterioration of the water-physical properties, the formation of compaction below the topsoil, and ultimately the reduction of soil fertility. The article makes specific suggestions to prevent this process. It was also identified based on the calculations that the specific surface area of the soil, rich in silt, dust and colloidal particles, is many times larger than the specific surface area of sandy soil. The specific surface area of colloidal silt is 43,000 times larger than the specific surface area of dust and 130,000 times larger than the specific surface area of sand.


HortScience ◽  
1995 ◽  
Vol 30 (4) ◽  
pp. 794B-794
Author(s):  
Bert T. Swanson ◽  
James B. Calkins

Five composted Municipal Solid Waste (MSW) (garbage) products and a composted manure were evaluated as container growing media components on eight woody and herbaceous plants. Plant growth response to the different composts and to the quality of compost used was species-specific. Media UM Manure 100 provided the greatest increase in plant height across all species during the first year. However, only one species, V. lentaga, actually ranked number one in UM Manure 100. J.h. `Blue Chip' and A. tuberosa both grew the tallest in Control I. The remaining five species grew tallest in five different media. Therefore, several amended media can provide increased plant height for specific species; however, the top three media for plant height across all species were: #1 UM Manure 100, #2 Prairieland 50, and #3 Pennington 50. Plant height was the lowest in Recomp 100 media. Pennington 50 provided the greatest increase in plant volume. Media producing the highest plant dry weights across all species were: #1 Prairieland 50, #2 Pennington 50 and #3 UM Manure 50. Plants grown in Recomp 100 had the lowest plant dry weight. Media physical properties such as media drainage and aeration were affected by amendment quality and quantity.


1994 ◽  
Vol 31 (5) ◽  
pp. 703-713 ◽  
Author(s):  
Arne Instanes ◽  
David C. Sego ◽  
Kofi Addo

During the winter of 1990–1991, a field research program was undertaken to investigate the in situ properties of spray ice, since information on the mechanical and physical properties of undisturbed field-produced spray ice is scarce. The main objective of this research was to retrieve undisturbed field samples for laboratory characterization and to make field measurements to assist in studying the formation processes and physical properties after formation. For this purpose, a spray-ice pad was constructed in the freshwater Tuktoyaktuk Harbour, Northwest Territories, Canada. The 4.3 m thick pad was partly grounded in water depths of 3–6 m and had a maximum freeboard of 2.2 m. The spray-ice pad was constructed using a mobile spray-ice system placed on the first-year ice sheet. The ice production efficiency of the system was measured and found to give an ice content higher than 50%. A total of 11.8 m of cores of nonsaturated undisturbed spray ice were retrieved from three locations on the pad and transported to a cold room facility for density, shear wave velocity, and mechanical behavior testing. In addition, surface wave testing of the in situ spray ice and first-year ice was performed. This paper describes the field study and the methodologies employed to carry out this research. Key words : spray ice, construction, sampling, density, Rayleigh wave velocity.


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