 |
| Titel |
Deriving snow hardness from density and its application to the 1-D snow cover model SNOWPACK |
| VerfasserIn |
F. Monti, J. Schweizer |
| Konferenz |
EGU General Assembly 2012
|
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 14 (2012) |
| Datensatznummer |
250069503
|
|
|
|
|
|
| Zusammenfassung |
| Estimating snow density (Ïs) based on snow hardness and grain type is often exploited
in snow science. In snow hydrology snow water equivalent (SWE) that strongly
depends on Ïs needs to be determined; in avalanche forecasting an appropriate
calculation of Ïs is crucial to assess the load on a possible weak layer. However,
collecting Ïs is time consuming and difficult to do for very thin layers, and thus a
parameterisation of Ïson hand hardness is useful. On the other hand, the 1D snow cover
model SNOWPACK derives snow hardness on simulated snow density. Recently, a new snow
settling parameterization was introduced in the model which affects the simulation
of density so that a new calibration is needed. We established a relation between
Ïsand hand hardness which is representative for various climatic regions of the
European Alps. Two data sets including 14’455 dry-snow layers with measured
density, grain type and hand hardness were used to relate density to hand hardness
for the major grain types. The data were collected in the surroundings of Davos
(Switzerland) and in the Veneto region (Italy), and cover different climatic regions and
elevations. We applied least square and robust regressions to explore the data. The
regression equations for both data sets were generally in reasonable agreement. The
data collected in the Veneto region showed a higher variance than those of Davos;
nevertheless the Veneto data was normally distributed and the mean values of Ïs and hand
hardness were highly correlated (R2 -¥ 0.9). Only for the grain type melt forms the
correlation was lower. The linear relations were then used for the model calibration of
SNOWPACK. First hardness simulations obtained with the different settings of the
model are promising as simulated hardness is in fair agreement with observed values |
|
|
|
|
|
|