The surface albedo of the Greenland ice sheet: satellite-derived and in situ measurements in the Søndre Strømfjord area during the 1991 melt season
Abstract The temporal and spatial variation in the surface albedo of the Greenland ice sheet during the ablation season of 1991 is investigated. The study focuses on an area east of Søndre Strømfjord measuring 200 km by 200 km and centred at 67°5′ N, 48° 13′W. The analysis is based on satellite radi...
Published in: | Journal of Glaciology |
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Language: | English |
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Cambridge University Press (CUP)
1996
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Online Access: | http://dx.doi.org/10.1017/s0022143000004214 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143000004214 |
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crcambridgeupr:10.1017/s0022143000004214 2024-09-15T18:09:12+00:00 The surface albedo of the Greenland ice sheet: satellite-derived and in situ measurements in the Søndre Strømfjord area during the 1991 melt season Knap, Wouter H. Oerlemans, Johannes 1996 http://dx.doi.org/10.1017/s0022143000004214 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143000004214 en eng Cambridge University Press (CUP) Journal of Glaciology volume 42, issue 141, page 364-374 ISSN 0022-1430 1727-5652 journal-article 1996 crcambridgeupr https://doi.org/10.1017/s0022143000004214 2024-07-24T04:02:42Z Abstract The temporal and spatial variation in the surface albedo of the Greenland ice sheet during the ablation season of 1991 is investigated. The study focuses on an area east of Søndre Strømfjord measuring 200 km by 200 km and centred at 67°5′ N, 48° 13′W. The analysis is based on satellite radiance measurements carried out by the Advanced Very High Resolution Radiometer (AVHRR). The broad-band albedo is estimated from the albedos in channel 1 (visible) and channel 2 (near-infrared). The results are calibrated with the surface albedo of sea and dry snow. Satellite-derived albedos are compared with GIMEX ground measurements at three stations. There is a high degree of consistency in temporal variation at two of the three stations. Large systematic differences are attributed to albedo variations on sub-pixel scale. In the course of the ablation season four zones appear, each parallel to the ice edge. It is proposed that these are, in order of increasing altitude: (I) clean and dry ice, (II) ice with surface water, (III) superimposed ice, and (IV) snow. An extensive description of these zones is given on the basis of the situation on 25 July 1991. Zones I, III and IV reveal fairly constant albedos (0.46, 0.65 and 0.75 on average), whereas zone II is characterised by an albedo minimum (0.34). Survey of the western margin of the Greenland ice sheet (up to 71° N) shows that the zonation occurs between 66° and 70° N. Article in Journal/Newspaper Greenland Ice Sheet Journal of Glaciology Søndre strømfjord Cambridge University Press Journal of Glaciology 42 141 364 374 |
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Open Polar |
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Cambridge University Press |
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crcambridgeupr |
language |
English |
description |
Abstract The temporal and spatial variation in the surface albedo of the Greenland ice sheet during the ablation season of 1991 is investigated. The study focuses on an area east of Søndre Strømfjord measuring 200 km by 200 km and centred at 67°5′ N, 48° 13′W. The analysis is based on satellite radiance measurements carried out by the Advanced Very High Resolution Radiometer (AVHRR). The broad-band albedo is estimated from the albedos in channel 1 (visible) and channel 2 (near-infrared). The results are calibrated with the surface albedo of sea and dry snow. Satellite-derived albedos are compared with GIMEX ground measurements at three stations. There is a high degree of consistency in temporal variation at two of the three stations. Large systematic differences are attributed to albedo variations on sub-pixel scale. In the course of the ablation season four zones appear, each parallel to the ice edge. It is proposed that these are, in order of increasing altitude: (I) clean and dry ice, (II) ice with surface water, (III) superimposed ice, and (IV) snow. An extensive description of these zones is given on the basis of the situation on 25 July 1991. Zones I, III and IV reveal fairly constant albedos (0.46, 0.65 and 0.75 on average), whereas zone II is characterised by an albedo minimum (0.34). Survey of the western margin of the Greenland ice sheet (up to 71° N) shows that the zonation occurs between 66° and 70° N. |
format |
Article in Journal/Newspaper |
author |
Knap, Wouter H. Oerlemans, Johannes |
spellingShingle |
Knap, Wouter H. Oerlemans, Johannes The surface albedo of the Greenland ice sheet: satellite-derived and in situ measurements in the Søndre Strømfjord area during the 1991 melt season |
author_facet |
Knap, Wouter H. Oerlemans, Johannes |
author_sort |
Knap, Wouter H. |
title |
The surface albedo of the Greenland ice sheet: satellite-derived and in situ measurements in the Søndre Strømfjord area during the 1991 melt season |
title_short |
The surface albedo of the Greenland ice sheet: satellite-derived and in situ measurements in the Søndre Strømfjord area during the 1991 melt season |
title_full |
The surface albedo of the Greenland ice sheet: satellite-derived and in situ measurements in the Søndre Strømfjord area during the 1991 melt season |
title_fullStr |
The surface albedo of the Greenland ice sheet: satellite-derived and in situ measurements in the Søndre Strømfjord area during the 1991 melt season |
title_full_unstemmed |
The surface albedo of the Greenland ice sheet: satellite-derived and in situ measurements in the Søndre Strømfjord area during the 1991 melt season |
title_sort |
surface albedo of the greenland ice sheet: satellite-derived and in situ measurements in the søndre strømfjord area during the 1991 melt season |
publisher |
Cambridge University Press (CUP) |
publishDate |
1996 |
url |
http://dx.doi.org/10.1017/s0022143000004214 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143000004214 |
genre |
Greenland Ice Sheet Journal of Glaciology Søndre strømfjord |
genre_facet |
Greenland Ice Sheet Journal of Glaciology Søndre strømfjord |
op_source |
Journal of Glaciology volume 42, issue 141, page 364-374 ISSN 0022-1430 1727-5652 |
op_doi |
https://doi.org/10.1017/s0022143000004214 |
container_title |
Journal of Glaciology |
container_volume |
42 |
container_issue |
141 |
container_start_page |
364 |
op_container_end_page |
374 |
_version_ |
1810446626127347712 |