Structure and dynamics of the summertime atmospheric boundary layer over the Antarctic plateau: 2. Heat, moisture, and momentum budgets
This paper presents the summertime budgets of heat, moisture and momentum in the atmospheric boundary layer at Kohnen base (75 000S, 0 040E, 2892 m above sea level), located in the interior of East Antarctica. For this purpose we performed a model simulation for clear-sky conditions and constant lar...
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ftunivutrecht:oai:dspace.library.uu.nl:1874/43677 2023-07-23T04:15:09+02:00 Structure and dynamics of the summertime atmospheric boundary layer over the Antarctic plateau: 2. Heat, moisture, and momentum budgets van As, D. van den Broeke, M.R. Marine and Atmospheric Research Afd Marine and Atmospheric Research Sub Dynamics Meteorology 2006 application/pdf https://dspace.library.uu.nl/handle/1874/43677 other unknown 2169-897X https://dspace.library.uu.nl/handle/1874/43677 info:eu-repo/semantics/EmbargoedAccess Article 2006 ftunivutrecht 2023-07-01T23:41:37Z This paper presents the summertime budgets of heat, moisture and momentum in the atmospheric boundary layer at Kohnen base (75 000S, 0 040E, 2892 m above sea level), located in the interior of East Antarctica. For this purpose we performed a model simulation for clear-sky conditions and constant large-scale forcing, using a high-resolution one-dimensional atmospheric model which has been validated by observations (see van As et al., 2006). Turbulent exchange is the dominant component in the heat budget, heating the daytime well-mixed layer by a maximum of 1.0 K h 1. Radiative heating and cooling are important, and are largest near the surface and just above and below the large temperature and humidity gradients of the nighttime stable layer. Vertical heat advection, which is introduced by the wind speed component along the slope, is the smallest heat-budget component in the atmospheric boundary layer, but becomes significant above it. The same is valid for vertical advection in the moisture budget, which is again dominated by turbulent exchange in the atmospheric boundary layer. The model generates solid precipitation (diamond dust) in the nighttime stable boundary layer. In the stable layer the temperature deficit with respect to the free atmosphere can be larger than 10 K, forcing a relatively large katabatic acceleration (up to 2.7ms 1 h 1). Katabatic forcing is chiefly opposed by turbulent momentum transfer (friction). The katabatic forcing decreases with height but is nonzero above the atmospheric boundary layer. In the nighttime stable layer we find a jet which is chiefly forced by katabatics, and in the residual layer above it we find alternating wind maxima and minima as a result of an inertial oscillation. Article in Journal/Newspaper Antarc* Antarctic Antarctica East Antarctica Utrecht University Repository Antarctic East Antarctica Kohnen ENVELOPE(0.000,0.000,-75.000,-75.000) The Antarctic |
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Open Polar |
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Utrecht University Repository |
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ftunivutrecht |
language |
unknown |
description |
This paper presents the summertime budgets of heat, moisture and momentum in the atmospheric boundary layer at Kohnen base (75 000S, 0 040E, 2892 m above sea level), located in the interior of East Antarctica. For this purpose we performed a model simulation for clear-sky conditions and constant large-scale forcing, using a high-resolution one-dimensional atmospheric model which has been validated by observations (see van As et al., 2006). Turbulent exchange is the dominant component in the heat budget, heating the daytime well-mixed layer by a maximum of 1.0 K h 1. Radiative heating and cooling are important, and are largest near the surface and just above and below the large temperature and humidity gradients of the nighttime stable layer. Vertical heat advection, which is introduced by the wind speed component along the slope, is the smallest heat-budget component in the atmospheric boundary layer, but becomes significant above it. The same is valid for vertical advection in the moisture budget, which is again dominated by turbulent exchange in the atmospheric boundary layer. The model generates solid precipitation (diamond dust) in the nighttime stable boundary layer. In the stable layer the temperature deficit with respect to the free atmosphere can be larger than 10 K, forcing a relatively large katabatic acceleration (up to 2.7ms 1 h 1). Katabatic forcing is chiefly opposed by turbulent momentum transfer (friction). The katabatic forcing decreases with height but is nonzero above the atmospheric boundary layer. In the nighttime stable layer we find a jet which is chiefly forced by katabatics, and in the residual layer above it we find alternating wind maxima and minima as a result of an inertial oscillation. |
author2 |
Marine and Atmospheric Research Afd Marine and Atmospheric Research Sub Dynamics Meteorology |
format |
Article in Journal/Newspaper |
author |
van As, D. van den Broeke, M.R. |
spellingShingle |
van As, D. van den Broeke, M.R. Structure and dynamics of the summertime atmospheric boundary layer over the Antarctic plateau: 2. Heat, moisture, and momentum budgets |
author_facet |
van As, D. van den Broeke, M.R. |
author_sort |
van As, D. |
title |
Structure and dynamics of the summertime atmospheric boundary layer over the Antarctic plateau: 2. Heat, moisture, and momentum budgets |
title_short |
Structure and dynamics of the summertime atmospheric boundary layer over the Antarctic plateau: 2. Heat, moisture, and momentum budgets |
title_full |
Structure and dynamics of the summertime atmospheric boundary layer over the Antarctic plateau: 2. Heat, moisture, and momentum budgets |
title_fullStr |
Structure and dynamics of the summertime atmospheric boundary layer over the Antarctic plateau: 2. Heat, moisture, and momentum budgets |
title_full_unstemmed |
Structure and dynamics of the summertime atmospheric boundary layer over the Antarctic plateau: 2. Heat, moisture, and momentum budgets |
title_sort |
structure and dynamics of the summertime atmospheric boundary layer over the antarctic plateau: 2. heat, moisture, and momentum budgets |
publishDate |
2006 |
url |
https://dspace.library.uu.nl/handle/1874/43677 |
long_lat |
ENVELOPE(0.000,0.000,-75.000,-75.000) |
geographic |
Antarctic East Antarctica Kohnen The Antarctic |
geographic_facet |
Antarctic East Antarctica Kohnen The Antarctic |
genre |
Antarc* Antarctic Antarctica East Antarctica |
genre_facet |
Antarc* Antarctic Antarctica East Antarctica |
op_relation |
2169-897X https://dspace.library.uu.nl/handle/1874/43677 |
op_rights |
info:eu-repo/semantics/EmbargoedAccess |
_version_ |
1772189146711851008 |