Role of Debris Cover in the Thermal Physics of Glaciers
Abstract A mathematical model is presented of non-stationary melting processes of ice including particles of morainic material. The problem is treated as a Stephen-type one with the phase boundary of ice melting being located under the debris cover. The main terms of the heat-balance equation for a...
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Language: | English |
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Cambridge University Press (CUP)
1986
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Online Access: | http://dx.doi.org/10.1017/s0022143000015598 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143000015598 |
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crcambridgeupr:10.1017/s0022143000015598 2024-05-19T07:43:13+00:00 Role of Debris Cover in the Thermal Physics of Glaciers Bozhinskiy, A. N. Krass, M. S. Popovnin, V. V. 1986 http://dx.doi.org/10.1017/s0022143000015598 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143000015598 en eng Cambridge University Press (CUP) Journal of Glaciology volume 32, issue 111, page 255-266 ISSN 0022-1430 1727-5652 journal-article 1986 crcambridgeupr https://doi.org/10.1017/s0022143000015598 2024-05-02T06:51:11Z Abstract A mathematical model is presented of non-stationary melting processes of ice including particles of morainic material. The problem is treated as a Stephen-type one with the phase boundary of ice melting being located under the debris cover. The main terms of the heat-balance equation for a glacier surface are solar radiation and convective heat transfer. The quantitative relationships characterizing the effect of glacier run-off augmentation from under a thin layer of debris cover are obtained for different bulk moraine concentrations inside the ice. The concept of equivalent time is introduced. It is defined as the time elapsed until the moment the sub-moraine ice-ablation rate becomes equal to the ablation rate of clean ice. This moment signifies the beginning of the shielding stage. Thus, a glacier can be considered as a self-controlling system with respect to its summer run-off. A series of numerical tests for Djankuat glacier, Central Caucasus, has been carried out. The dynamics of moraine-cover growth and alterations of seasonal ablation rate under debris show perfect agreement between the computed data and the results of 14 years of direct observations. Some practical recommendations concerning artificial blackening of a glacier surface for augmentation of liquid run-off are presented. Conditions promoting increase of run-off are: relatively high albedo, relatively low summer air temperature, and relatively small convective heat transfer between the air and the ice surface. The method of artificially blackening a glacier surface is by means of a durable thin dark polymer film. In conclusion, some further aspects of the problem are discussed. Article in Journal/Newspaper Journal of Glaciology Cambridge University Press Journal of Glaciology 32 111 255 266 |
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Cambridge University Press |
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language |
English |
description |
Abstract A mathematical model is presented of non-stationary melting processes of ice including particles of morainic material. The problem is treated as a Stephen-type one with the phase boundary of ice melting being located under the debris cover. The main terms of the heat-balance equation for a glacier surface are solar radiation and convective heat transfer. The quantitative relationships characterizing the effect of glacier run-off augmentation from under a thin layer of debris cover are obtained for different bulk moraine concentrations inside the ice. The concept of equivalent time is introduced. It is defined as the time elapsed until the moment the sub-moraine ice-ablation rate becomes equal to the ablation rate of clean ice. This moment signifies the beginning of the shielding stage. Thus, a glacier can be considered as a self-controlling system with respect to its summer run-off. A series of numerical tests for Djankuat glacier, Central Caucasus, has been carried out. The dynamics of moraine-cover growth and alterations of seasonal ablation rate under debris show perfect agreement between the computed data and the results of 14 years of direct observations. Some practical recommendations concerning artificial blackening of a glacier surface for augmentation of liquid run-off are presented. Conditions promoting increase of run-off are: relatively high albedo, relatively low summer air temperature, and relatively small convective heat transfer between the air and the ice surface. The method of artificially blackening a glacier surface is by means of a durable thin dark polymer film. In conclusion, some further aspects of the problem are discussed. |
format |
Article in Journal/Newspaper |
author |
Bozhinskiy, A. N. Krass, M. S. Popovnin, V. V. |
spellingShingle |
Bozhinskiy, A. N. Krass, M. S. Popovnin, V. V. Role of Debris Cover in the Thermal Physics of Glaciers |
author_facet |
Bozhinskiy, A. N. Krass, M. S. Popovnin, V. V. |
author_sort |
Bozhinskiy, A. N. |
title |
Role of Debris Cover in the Thermal Physics of Glaciers |
title_short |
Role of Debris Cover in the Thermal Physics of Glaciers |
title_full |
Role of Debris Cover in the Thermal Physics of Glaciers |
title_fullStr |
Role of Debris Cover in the Thermal Physics of Glaciers |
title_full_unstemmed |
Role of Debris Cover in the Thermal Physics of Glaciers |
title_sort |
role of debris cover in the thermal physics of glaciers |
publisher |
Cambridge University Press (CUP) |
publishDate |
1986 |
url |
http://dx.doi.org/10.1017/s0022143000015598 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143000015598 |
genre |
Journal of Glaciology |
genre_facet |
Journal of Glaciology |
op_source |
Journal of Glaciology volume 32, issue 111, page 255-266 ISSN 0022-1430 1727-5652 |
op_doi |
https://doi.org/10.1017/s0022143000015598 |
container_title |
Journal of Glaciology |
container_volume |
32 |
container_issue |
111 |
container_start_page |
255 |
op_container_end_page |
266 |
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1799482941588373504 |