The Effect of Slope, Exposure and Mountain Screening on the Solar Radiation of McCall Glacier, Alaska: A Contribution to the International Hydrological Decade
The McCall Glacier is located in the Brooks Range, north Alaska. Most of its slopes have a northerly exposure with an inclination between 5°and 15°. The reduction in direct solar radiation owing to this northerly exposure is small (1.7%) in summer (ablation period, solar declination 20°), as the red...
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Cambridge University Press (CUP)
1974
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crcambridgeupr:10.1017/s0022143000023030 2024-03-03T08:43:21+00:00 The Effect of Slope, Exposure and Mountain Screening on the Solar Radiation of McCall Glacier, Alaska: A Contribution to the International Hydrological Decade Wendler, Gerd Ishikawa, Nobuyoshi 1974 http://dx.doi.org/10.1017/s0022143000023030 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143000023030 en eng Cambridge University Press (CUP) Journal of Glaciology volume 13, issue 68, page 213-226 ISSN 0022-1430 1727-5652 Earth-Surface Processes journal-article 1974 crcambridgeupr https://doi.org/10.1017/s0022143000023030 2024-02-08T08:47:47Z The McCall Glacier is located in the Brooks Range, north Alaska. Most of its slopes have a northerly exposure with an inclination between 5°and 15°. The reduction in direct solar radiation owing to this northerly exposure is small (1.7%) in summer (ablation period, solar declination 20°), as the reduction in radiation received on a north slope during the noon hours is mostly compensated by the increase of energy during the “night” hours, as the sun does not set at that latitude in summer. With the shortening of the solar path, the decrease in direct solar radiation as compared with a horizontal surface becomes more important. At the equinox the loss is 24.8%, and at a solar declination of —10° (20 October or 24 February) even higher with 32.6%. A further reduction in solar radiation is caused by the steep mountains, which surround the McCall Glacier. The duration of sunshine is reduced during the ablation period by nearly 40%, which, however, represents an energy loss of only 13.4%, as the screening effect of the mountains is most important with low solar angles, i.e. at times when the total energy received at the surface is small. The screening effect of the mountains becomes more severe with lower sun angles and shorter paths of the sun. During the equinox a loss in duration of 67.6%, and in energy of 55.7% is observed. For a solar declination of —10°, there is hardly any direct sunshine on the glacier at all. There is then a loss in duration of 93.6%, resulting in a loss of energy of 87.8%. Together, these two components reduce the direct solar radiation by about 15% in the ablation period, 67% at the equinox and more than 90% at a solar declination of —10°. Article in Journal/Newspaper Brooks Range glacier Journal of Glaciology north slope Alaska Cambridge University Press McCall ENVELOPE(-66.619,-66.619,-67.029,-67.029) Journal of Glaciology 13 68 213 226 |
institution |
Open Polar |
collection |
Cambridge University Press |
op_collection_id |
crcambridgeupr |
language |
English |
topic |
Earth-Surface Processes |
spellingShingle |
Earth-Surface Processes Wendler, Gerd Ishikawa, Nobuyoshi The Effect of Slope, Exposure and Mountain Screening on the Solar Radiation of McCall Glacier, Alaska: A Contribution to the International Hydrological Decade |
topic_facet |
Earth-Surface Processes |
description |
The McCall Glacier is located in the Brooks Range, north Alaska. Most of its slopes have a northerly exposure with an inclination between 5°and 15°. The reduction in direct solar radiation owing to this northerly exposure is small (1.7%) in summer (ablation period, solar declination 20°), as the reduction in radiation received on a north slope during the noon hours is mostly compensated by the increase of energy during the “night” hours, as the sun does not set at that latitude in summer. With the shortening of the solar path, the decrease in direct solar radiation as compared with a horizontal surface becomes more important. At the equinox the loss is 24.8%, and at a solar declination of —10° (20 October or 24 February) even higher with 32.6%. A further reduction in solar radiation is caused by the steep mountains, which surround the McCall Glacier. The duration of sunshine is reduced during the ablation period by nearly 40%, which, however, represents an energy loss of only 13.4%, as the screening effect of the mountains is most important with low solar angles, i.e. at times when the total energy received at the surface is small. The screening effect of the mountains becomes more severe with lower sun angles and shorter paths of the sun. During the equinox a loss in duration of 67.6%, and in energy of 55.7% is observed. For a solar declination of —10°, there is hardly any direct sunshine on the glacier at all. There is then a loss in duration of 93.6%, resulting in a loss of energy of 87.8%. Together, these two components reduce the direct solar radiation by about 15% in the ablation period, 67% at the equinox and more than 90% at a solar declination of —10°. |
format |
Article in Journal/Newspaper |
author |
Wendler, Gerd Ishikawa, Nobuyoshi |
author_facet |
Wendler, Gerd Ishikawa, Nobuyoshi |
author_sort |
Wendler, Gerd |
title |
The Effect of Slope, Exposure and Mountain Screening on the Solar Radiation of McCall Glacier, Alaska: A Contribution to the International Hydrological Decade |
title_short |
The Effect of Slope, Exposure and Mountain Screening on the Solar Radiation of McCall Glacier, Alaska: A Contribution to the International Hydrological Decade |
title_full |
The Effect of Slope, Exposure and Mountain Screening on the Solar Radiation of McCall Glacier, Alaska: A Contribution to the International Hydrological Decade |
title_fullStr |
The Effect of Slope, Exposure and Mountain Screening on the Solar Radiation of McCall Glacier, Alaska: A Contribution to the International Hydrological Decade |
title_full_unstemmed |
The Effect of Slope, Exposure and Mountain Screening on the Solar Radiation of McCall Glacier, Alaska: A Contribution to the International Hydrological Decade |
title_sort |
effect of slope, exposure and mountain screening on the solar radiation of mccall glacier, alaska: a contribution to the international hydrological decade |
publisher |
Cambridge University Press (CUP) |
publishDate |
1974 |
url |
http://dx.doi.org/10.1017/s0022143000023030 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143000023030 |
long_lat |
ENVELOPE(-66.619,-66.619,-67.029,-67.029) |
geographic |
McCall |
geographic_facet |
McCall |
genre |
Brooks Range glacier Journal of Glaciology north slope Alaska |
genre_facet |
Brooks Range glacier Journal of Glaciology north slope Alaska |
op_source |
Journal of Glaciology volume 13, issue 68, page 213-226 ISSN 0022-1430 1727-5652 |
op_doi |
https://doi.org/10.1017/s0022143000023030 |
container_title |
Journal of Glaciology |
container_volume |
13 |
container_issue |
68 |
container_start_page |
213 |
op_container_end_page |
226 |
_version_ |
1792498782835834880 |