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| Titel |
Wind effects on snow cover in Pascua-Lama, Dry Andes of Chile |
| VerfasserIn |
Stef Lhermitte, Simon Gascoin, Christophe Kinnard, Kirsten Bortels, Glen E. Liston |
| Konferenz |
EGU General Assembly 2013
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 15 (2013) |
| Datensatznummer |
250081986
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| Zusammenfassung |
| We present the application of a distributed snow model (SnowModel) on the instrumented site
of Pascua-Lama in the Dry Andes (2600–5630 m above sea level, 29Ë S). A model
experiment was performed to assess the effect of wind on snow cover patterns. A particular
objective was to evaluate the role of blowing snow on the glacier formation. The model was
run using the data from 11 weather stations over a complete snow season. First, a
cross-validation of the meteorological variables interpolation model (MicroMet submodel)
was performed to evaluate the performance of the simulated meteorological forcing.
Secondly, two SnowModel simulations were set up: one without and the other with
the wind transport submodel (SnowTran-3D). Results from both simulations were
compared with in situ snow depth measurements and remotely sensed snow cover
data. The inclusion of SnowTran-3D does not change the fact that the model is
unable to capture the small-scale snow depth spatial variability (as captured by
in situ snow depth sensors). However, remote sensing data (MODIS daily snow
product) indicate that at broader scales the wind module produced an improved
representation of the snow distribution near the glaciers (2-D correlation coefficient
increased from R = 0.04 to R = 0.27). The model outputs show that a key process is the
sublimation of blowing snow, which amounts to 18% of the total ablation over the
whole study area, with a high spatial variability. The effect of snow drift is more
visible on the glaciers, where wind-transported snow accumulates preferentially.
Net deposition occurred for 43% of the glacier grid points, whereas it is only 23%
of non-glacier grid points located above the minimum glacier altitude (4475 m). |
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