Daily cycle of the surface energy balance in Antarctica and the influence of clouds
We present the summertime daily cycle of the Antarctic surface energy balance (SEB) and its sensitivity to cloud cover. We use data of automatic weather stations (AWS) located in four major Antarctic climate zones: the coastal ice shelf, the coastal and interior katabatic wind zone and the interior...
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ftunivutrecht:oai:dspace.library.uu.nl:1874/42857 2023-07-23T04:15:09+02:00 Daily cycle of the surface energy balance in Antarctica and the influence of clouds van den Broeke, M.R. Reijmer, C.H. van As, D. Boot, W. Marine and Atmospheric Research Sub Dynamics Meteorology Dep Natuurkunde Afd Marine and Atmospheric Research 2006 text/plain https://dspace.library.uu.nl/handle/1874/42857 other unknown 0899-8418 https://dspace.library.uu.nl/handle/1874/42857 info:eu-repo/semantics/OpenAccess Article 2006 ftunivutrecht 2023-07-01T23:41:40Z We present the summertime daily cycle of the Antarctic surface energy balance (SEB) and its sensitivity to cloud cover. We use data of automatic weather stations (AWS) located in four major Antarctic climate zones: the coastal ice shelf, the coastal and interior katabatic wind zone and the interior plateau. Absorbed short wave radiation drives the daily cycle of the SEB, in spite of the high surface albedo (0.84–0.88). The dominant heat sink is the cooling by long wave radiation, but this flux is distributed more evenly throughout the day so that a pronounced daily cycle in net all-wave radiation remains with all-sky night-time heat losses of 20–30 W m−2 and noontime heat gains of 30–40 W m−2. During the night, heat is re-supplied to the snow surface by the sensible heat flux, especially in the katabatic wind zone, and the sub-surface heat flux. Daytime radiative energy excess is removed from the surface by sublimation (except at the high plateau) and sub-surface heat transport. Daytime convection occurs at all sites around solar noon but is generally weak. Spatial differences in the SEB are largely controlled by differences in cloud cover. Clouds are associated with higher surface temperatures and near-surface wind speeds. This especially limits nocturnal cooling, so that the strongest daytime convection is found during overcast conditions on the interior plateau. Article in Journal/Newspaper Antarc* Antarctic Antarctica Ice Shelf Utrecht University Repository Antarctic The Antarctic |
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Utrecht University Repository |
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ftunivutrecht |
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unknown |
description |
We present the summertime daily cycle of the Antarctic surface energy balance (SEB) and its sensitivity to cloud cover. We use data of automatic weather stations (AWS) located in four major Antarctic climate zones: the coastal ice shelf, the coastal and interior katabatic wind zone and the interior plateau. Absorbed short wave radiation drives the daily cycle of the SEB, in spite of the high surface albedo (0.84–0.88). The dominant heat sink is the cooling by long wave radiation, but this flux is distributed more evenly throughout the day so that a pronounced daily cycle in net all-wave radiation remains with all-sky night-time heat losses of 20–30 W m−2 and noontime heat gains of 30–40 W m−2. During the night, heat is re-supplied to the snow surface by the sensible heat flux, especially in the katabatic wind zone, and the sub-surface heat flux. Daytime radiative energy excess is removed from the surface by sublimation (except at the high plateau) and sub-surface heat transport. Daytime convection occurs at all sites around solar noon but is generally weak. Spatial differences in the SEB are largely controlled by differences in cloud cover. Clouds are associated with higher surface temperatures and near-surface wind speeds. This especially limits nocturnal cooling, so that the strongest daytime convection is found during overcast conditions on the interior plateau. |
author2 |
Marine and Atmospheric Research Sub Dynamics Meteorology Dep Natuurkunde Afd Marine and Atmospheric Research |
format |
Article in Journal/Newspaper |
author |
van den Broeke, M.R. Reijmer, C.H. van As, D. Boot, W. |
spellingShingle |
van den Broeke, M.R. Reijmer, C.H. van As, D. Boot, W. Daily cycle of the surface energy balance in Antarctica and the influence of clouds |
author_facet |
van den Broeke, M.R. Reijmer, C.H. van As, D. Boot, W. |
author_sort |
van den Broeke, M.R. |
title |
Daily cycle of the surface energy balance in Antarctica and the influence of clouds |
title_short |
Daily cycle of the surface energy balance in Antarctica and the influence of clouds |
title_full |
Daily cycle of the surface energy balance in Antarctica and the influence of clouds |
title_fullStr |
Daily cycle of the surface energy balance in Antarctica and the influence of clouds |
title_full_unstemmed |
Daily cycle of the surface energy balance in Antarctica and the influence of clouds |
title_sort |
daily cycle of the surface energy balance in antarctica and the influence of clouds |
publishDate |
2006 |
url |
https://dspace.library.uu.nl/handle/1874/42857 |
geographic |
Antarctic The Antarctic |
geographic_facet |
Antarctic The Antarctic |
genre |
Antarc* Antarctic Antarctica Ice Shelf |
genre_facet |
Antarc* Antarctic Antarctica Ice Shelf |
op_relation |
0899-8418 https://dspace.library.uu.nl/handle/1874/42857 |
op_rights |
info:eu-repo/semantics/OpenAccess |
_version_ |
1772189143990796288 |