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| Titel |
Small scale variability of snow properties on Antarctic sea ice |
| VerfasserIn |
Nander Wever, Katherine Leonard, Stephan Paul, Hans-Werner Jacobi, Martin Proksch, Michael Lehning |
| Konferenz |
EGU General Assembly 2016
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| Medientyp |
Artikel
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| Sprache |
en
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 18 (2016) |
| Datensatznummer |
250129426
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| Publikation (Nr.) |
 EGU/EGU2016-9538.pdf |
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| Zusammenfassung |
| Snow on sea ice plays an important role in air-ice-sea interactions, as snow accumulation may
for example increase the albedo. Snow is also able to smooth the ice surface, thereby
reducing the surface roughness, while at the same time it may generate new roughness
elements by interactions with the wind. Snow density is a key property in many
processes, for example by influencing the thermal conductivity of the snow layer,
radiative transfer inside the snow as well as the effects of aerodynamic forcing
on the snowpack. By comparing snow density and grain size from snow pits and
snow micro penetrometer (SMP) measurements, highly resolved density and grain
size profiles were acquired during two subsequent cruises of the RV Polarstern
in the Weddell Sea, Antarctica, between June and October 2013. During the first
cruise, SMP measurements were done along two approximately 40 m transects
with a horizontal resolution of approximately 30 cm. During the second cruise,
one transect was made with approximately 7.5 m resolution over a distance of 500
m. Average snow densities are about 300 kg/m3, but the analysis also reveals a
high spatial variability in snow density on sea ice in both horizontal and vertical
direction, ranging from roughly 180 to 360 kg/m3. This variability is expressed by
coherent snow structures over several meters. On the first cruise, the measurements
were accompanied by terrestrial laser scanning (TLS) on an area of 50x50 m2. The
comparison with the TLS data indicates that the spatial variability is exhibiting
similar spatial patterns as deviations in surface topology. This suggests a strong
influence from surface processes, for example wind, on the temporal development of
density or grain size profiles. The fundamental relationship between variations
in snow properties, surface roughness and changes therein as investigated in this
study is interpreted with respect to large-scale ice movement and the mass balance. |
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