Deterioration of Floating Ice Covers

1985 ◽  
Vol 107 (2) ◽  
pp. 177-182 ◽  
Author(s):  
G. D. Ashton
Keyword(s):  
Surface Albedo ◽  
Ice Cover ◽  
Short Wave ◽  
Wave Radiation ◽  
Strength Analysis ◽  
Short Wave Radiation ◽  
Beam Type ◽  
Unsteady Heat Conduction ◽  
Original Strength

The deterioration of floating ice covers is analyzed to determine under what conditions the ice cover loses strength due to internal melting. The analysis considers the interaction between sensible heat transfer and long wave radiation loss at the surface, the surface albedo, the short wave radiation penetration and absorption and the unsteady heat conduction within the ice. The thermal analysis then leads to a determination of the porosity of the ice that allows strength analysis to be made using beam-type analyses. The results provide criteria to determine when and how rapidly the ice cover loses strength and under what conditions it will regain the original strength associated with an ice cover of full integrity.

scholarly journals Albedo of Melting Sea Ice in the Southern Beaufort Sea

1971 ◽  
Vol 10 (58) ◽  
pp. 101-104 ◽  
Author(s):  
M.P. Langleben
Keyword(s):  
Sea Ice ◽  
Northwest Territories ◽  
Beaufort Sea ◽  
Ice Cover ◽  
Short Wave ◽  
Wave Radiation ◽  
Short Wave Radiation ◽  
Melting Period ◽  
Fast Ice ◽  
Made In

AbstractTwo Kipp hemispherical radiometers mounted back to back and suspended by an 18 m cable from a helicopter flying at an altitude of about 90 m were used to make measurements of incident and reflected short-wave radiation. The helicopter was brought to a hovering position at the instant of measurement to ensure that the radiometers were in the proper attitude and a photograph of the ice cover was taken at the same time. The observations were made in 1969 during 16 flights out of Tuktoyaktuk, Northwest Territories (lat. 69° 26’N., long. 133° 02’W.) over the fast ice extending 80 km north of Tuktoyaktuk. Values of albedo of the ice cover were found to decrease during the melting period according to the equation A = 0.59 —0.32P where P is the degree of puddling of the surface.

scholarly journals Radiation and Cloud Observations on a High Arctic Plateau Ice Cap

1987 ◽  
Vol 33 (114) ◽  
pp. 162-168 ◽  
Author(s):  
M.C. Serreze ◽  
R.S. Bradley
Keyword(s):  
Surface Albedo ◽  
High Surface ◽  
High Arctic ◽  
Short Wave ◽  
Wave Radiation ◽  
Net Radiation ◽  
Short Wave Radiation ◽  
Ice Cap ◽  
Long Wave ◽  
Long Wave Radiation

AbstractHourly measurements of incoming short-wave and long-wave radiation, surface albedo, and net radiation were made on and around a plateau ice cap on north-eastern Ellesmere Island during the summers of 1982 and 1983. These data were stratified by cloud type and amount. All cloud types increased incoming long-wave radiation, especially low dense clouds, fog, and clouds associated with snowfall. Relative transmission of incoming short-wave radiation, expressed as a percentage of clear-sky radiation receipts, was high for all cloud types compared to clouds at lower latitudes. With high surface albedo (≥0.75), net radiation was strongly and positively correlated with net long-wave radiation but showed little relationship to net short-wave radiation. By contrast, with low surface albedo (≤0.20) net radiation was negatively correlated with net long-wave radiation but positively correlated with net short-wave radiation. Under high-albedo conditions, an increase in cloudiness led to higher values of net radiation but under low-albedo conditions net radiation decreased as cloud cover increased. Survival of a snow cover would seem to be favoured if the seasonal decline in albedo is accompanied by a corresponding increase in cloudiness.

scholarly journals Albedo and Degree of Puddling of a Melting Cover of Sea Ice

1969 ◽  
Vol 8 (54) ◽  
pp. 407-412 ◽  
Author(s):  
M. P. Langleben
Keyword(s):  
Air Temperature ◽  
Time Lapse ◽  
Ice Cover ◽  
Short Wave ◽  
Ellesmere Island ◽  
Wave Radiation ◽  
Melting Time ◽  
Short Wave Radiation ◽  
Screen Height ◽  
Observation Period

AbstractContinuous measurements of incident and reflected short-wave radiation have been obtained from 12 May to 17 June 1968 on the ice cover at Tanquary Fiord, Ellesmere Island (lat. 81° 25′ N., long. 76° 50′ W.). The observations were made with radiometers suspended between two towers at a height of 50 ft (15 m) to sample an area large enough to be representative of the surface of the ice cover. From the start of surface melting, time-lapse photographs were taken at intervals of 3 h with a camera mounted on one of the towers at a height of 20 ft (6 m) and slanted below the horizontal.Values are presented, for the observation period, of incident short-wave radiation, albedo, air temperature at screen height and percentage of surface covered with melt pools. It is shown that the albedo decreases linearly with increasing area of water puddles.

scholarly journals Soil surface albedo and multispectral reflectance of short-wave radiation as a function of degree of soil slaking.

1980 ◽  
Vol 28 (4) ◽  
pp. 252-258
Author(s):  
G. van der Heide ◽  
A.J. Koolen
Keyword(s):  
Remote Sensing ◽  
Surface Albedo ◽  
Soil Surface ◽  
Short Wave ◽  
Wave Radiation ◽  
High Moisture ◽  
Short Wave Radiation ◽  
Surface Reflection ◽  
Moisture Contents ◽  
Dry Conditions

The feasibility of mapping the degree of soil slaking using remote sensing on the basis of reflected solar radiation was investigated in the laboratory. Relationships between soil surface reflection and wavelength of light were plotted for a range of soil moisture contents and degrees of soil slaking. Reflection tended to increase with decreasing moisture content. Slaking had little effect on reflection at high moisture contents, but slightly increased reflection at low moisture contents. The detection of slaking by spectral analysis is not recommended, while albedo measurements may be successful under dry conditions. (Abstract retrieved from CAB Abstracts by CABI’s permission)

scholarly journals Albedo of Melting Sea Ice in the Southern Beaufort Sea

1971 ◽  
Vol 10 (58) ◽  
pp. 101-104 ◽  
Author(s):  
M.P. Langleben
Keyword(s):  
Sea Ice ◽  
Northwest Territories ◽  
Beaufort Sea ◽  
Ice Cover ◽  
Short Wave ◽  
Wave Radiation ◽  
Short Wave Radiation ◽  
Melting Period ◽  
Fast Ice ◽  
Made In

Two Kipp hemispherical radiometers mounted back to back and suspended by an 18 m cable from a helicopter flying at an altitude of about 90 m were used to make measurements of incident and reflected short-wave radiation. The helicopter was brought to a hovering position at the instant of measurement to ensure that the radiometers were in the proper attitude and a photograph of the ice cover was taken at the same time. The observations were made in 1969 during 16 flights out of Tuktoyaktuk, Northwest Territories (lat. 69° 26’N., long. 133° 02’W.) over the fast ice extending 80 km north of Tuktoyaktuk. Values of albedo of the ice cover were found to decrease during the melting period according to the equationA= 0.59 —0.32PwherePis the degree of puddling of the surface.

scholarly journals Albedo and Degree of Puddling of a Melting Cover of Sea Ice

1969 ◽  
Vol 8 (54) ◽  
pp. 407-412 ◽  
Author(s):  
M. P. Langleben
Keyword(s):  
Air Temperature ◽  
Time Lapse ◽  
Ice Cover ◽  
Short Wave ◽  
Ellesmere Island ◽  
Wave Radiation ◽  
Melting Time ◽  
Short Wave Radiation ◽  
Screen Height ◽  
Observation Period

AbstractContinuous measurements of incident and reflected short-wave radiation have been obtained from 12 May to 17 June 1968 on the ice cover at Tanquary Fiord, Ellesmere Island (lat. 81° 25′ N., long. 76° 50′ W.). The observations were made with radiometers suspended between two towers at a height of 50 ft (15 m) to sample an area large enough to be representative of the surface of the ice cover. From the start of surface melting, time-lapse photographs were taken at intervals of 3 h with a camera mounted on one of the towers at a height of 20 ft (6 m) and slanted below the horizontal.Values are presented, for the observation period, of incident short-wave radiation, albedo, air temperature at screen height and percentage of surface covered with melt pools. It is shown that the albedo decreases linearly with increasing area of water puddles.

scholarly journals Radiation and Cloud Observations on a High Arctic Plateau Ice Cap

1987 ◽  
Vol 33 (114) ◽  
pp. 162-168 ◽  
Author(s):  
M.C. Serreze ◽  
R.S. Bradley
Keyword(s):  
Surface Albedo ◽  
High Surface ◽  
High Arctic ◽  
Short Wave ◽  
Wave Radiation ◽  
Net Radiation ◽  
Short Wave Radiation ◽  
Ice Cap ◽  
Long Wave ◽  
Long Wave Radiation

AbstractHourly measurements of incoming short-wave and long-wave radiation, surface albedo, and net radiation were made on and around a plateau ice cap on north-eastern Ellesmere Island during the summers of 1982 and 1983. These data were stratified by cloud type and amount. All cloud types increased incoming long-wave radiation, especially low dense clouds, fog, and clouds associated with snowfall. Relative transmission of incoming short-wave radiation, expressed as a percentage of clear-sky radiation receipts, was high for all cloud types compared to clouds at lower latitudes. With high surface albedo (≥0.75), net radiation was strongly and positively correlated with net long-wave radiation but showed little relationship to net short-wave radiation. By contrast, with low surface albedo (≤0.20) net radiation was negatively correlated with net long-wave radiation but positively correlated with net short-wave radiation. Under high-albedo conditions, an increase in cloudiness led to higher values of net radiation but under low-albedo conditions net radiation decreased as cloud cover increased. Survival of a snow cover would seem to be favoured if the seasonal decline in albedo is accompanied by a corresponding increase in cloudiness.

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