Heat-Budget Measurements on the Quelccaya Ice Cap, Peruvian Andes
Abstract During the June-August 1976 Quelccaya ice cap expedition, global, SW↓, and net long-wave radiation, LW↑↓, were measured through several complete day-night cycles, and for a wide range of cloudiness conditions. Field work further included albedo measurements along representative transects ac...
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Cambridge University Press (CUP)
1978
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Online Access: | http://dx.doi.org/10.1017/s0022143000021237 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143000021237 |
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crcambridgeupr:10.1017/s0022143000021237 2024-03-03T08:45:19+00:00 Heat-Budget Measurements on the Quelccaya Ice Cap, Peruvian Andes Hastenrath, Stefan 1978 http://dx.doi.org/10.1017/s0022143000021237 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143000021237 en eng Cambridge University Press (CUP) Journal of Glaciology volume 20, issue 82, page 85-97 ISSN 0022-1430 1727-5652 Earth-Surface Processes journal-article 1978 crcambridgeupr https://doi.org/10.1017/s0022143000021237 2024-02-08T08:46:13Z Abstract During the June-August 1976 Quelccaya ice cap expedition, global, SW↓, and net long-wave radiation, LW↑↓, were measured through several complete day-night cycles, and for a wide range of cloudiness conditions. Field work further included albedo measurements along representative transects across the ice cap and lysimeter-type estimates of ablation. Automatic stations recording wind, temperature and sunshine duration were also installed. Daily totals of SW↓ and LW↑↓ representative of completely clear and overcast days are derived. On this basis, empirical relationships allow the computation of monthly totals of radiation fluxes for an entire year from records of sunshine duration and temperature expected from the automatic stations. The larger part of the plateau is situated above 5400 m and has an albedo mostly in excess of 80%. Sub-freezing temperatures essentially limit ablation to the energetically expensive sublimation. For clear sky, daily totals of SW↓and LW↑↓ are of the order of 312 and 53 W m –2 , respectively. With the albedo found, net short-wave radiation SW↑↓ becomes of the same general magnitude as LW↑↓, and the energy left for ablation is near to nil. Cloudiness would reduce both SW↑↓ and LW↑↓, thus largely compensating the effect on the residual net radiation, SWLW↑↓. This is consistent with ablation measurements. Over the larger area of the ice plateau, ablation may be close to zero in a first approximation; some ablation, including melting, takes place near the lower-lying rim of the ice cap, and calving off steep cliffs seems to provide a major mechanism for the disposal of the ice mass. Article in Journal/Newspaper Ice cap Journal of Glaciology Cambridge University Press Journal of Glaciology 20 82 85 97 |
institution |
Open Polar |
collection |
Cambridge University Press |
op_collection_id |
crcambridgeupr |
language |
English |
topic |
Earth-Surface Processes |
spellingShingle |
Earth-Surface Processes Hastenrath, Stefan Heat-Budget Measurements on the Quelccaya Ice Cap, Peruvian Andes |
topic_facet |
Earth-Surface Processes |
description |
Abstract During the June-August 1976 Quelccaya ice cap expedition, global, SW↓, and net long-wave radiation, LW↑↓, were measured through several complete day-night cycles, and for a wide range of cloudiness conditions. Field work further included albedo measurements along representative transects across the ice cap and lysimeter-type estimates of ablation. Automatic stations recording wind, temperature and sunshine duration were also installed. Daily totals of SW↓ and LW↑↓ representative of completely clear and overcast days are derived. On this basis, empirical relationships allow the computation of monthly totals of radiation fluxes for an entire year from records of sunshine duration and temperature expected from the automatic stations. The larger part of the plateau is situated above 5400 m and has an albedo mostly in excess of 80%. Sub-freezing temperatures essentially limit ablation to the energetically expensive sublimation. For clear sky, daily totals of SW↓and LW↑↓ are of the order of 312 and 53 W m –2 , respectively. With the albedo found, net short-wave radiation SW↑↓ becomes of the same general magnitude as LW↑↓, and the energy left for ablation is near to nil. Cloudiness would reduce both SW↑↓ and LW↑↓, thus largely compensating the effect on the residual net radiation, SWLW↑↓. This is consistent with ablation measurements. Over the larger area of the ice plateau, ablation may be close to zero in a first approximation; some ablation, including melting, takes place near the lower-lying rim of the ice cap, and calving off steep cliffs seems to provide a major mechanism for the disposal of the ice mass. |
format |
Article in Journal/Newspaper |
author |
Hastenrath, Stefan |
author_facet |
Hastenrath, Stefan |
author_sort |
Hastenrath, Stefan |
title |
Heat-Budget Measurements on the Quelccaya Ice Cap, Peruvian Andes |
title_short |
Heat-Budget Measurements on the Quelccaya Ice Cap, Peruvian Andes |
title_full |
Heat-Budget Measurements on the Quelccaya Ice Cap, Peruvian Andes |
title_fullStr |
Heat-Budget Measurements on the Quelccaya Ice Cap, Peruvian Andes |
title_full_unstemmed |
Heat-Budget Measurements on the Quelccaya Ice Cap, Peruvian Andes |
title_sort |
heat-budget measurements on the quelccaya ice cap, peruvian andes |
publisher |
Cambridge University Press (CUP) |
publishDate |
1978 |
url |
http://dx.doi.org/10.1017/s0022143000021237 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143000021237 |
genre |
Ice cap Journal of Glaciology |
genre_facet |
Ice cap Journal of Glaciology |
op_source |
Journal of Glaciology volume 20, issue 82, page 85-97 ISSN 0022-1430 1727-5652 |
op_doi |
https://doi.org/10.1017/s0022143000021237 |
container_title |
Journal of Glaciology |
container_volume |
20 |
container_issue |
82 |
container_start_page |
85 |
op_container_end_page |
97 |
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1792500842499145728 |