 |
| Titel |
Thermal energy in dry snow avalanches |
| VerfasserIn |
W. Steinkogler, B. Sovilla, M. Lehning |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
1994-0416
|
| Digitales Dokument |
URL |
| Erschienen |
In: The Cryosphere ; 9, no. 5 ; Nr. 9, no. 5 (2015-09-17), S.1819-1830 |
| Datensatznummer |
250116850
|
| Publikation (Nr.) |
 copernicus.org/tc-9-1819-2015.pdf |
|
|
|
|
|
| Zusammenfassung |
| Avalanches can exhibit many different flow regimes from powder clouds to
slush flows. Flow regimes are largely controlled by the properties of the
snow released and entrained along the path. Recent investigations showed the
temperature of the moving snow to be one of the most important factors
controlling the mobility of the flow. The temperature of an avalanche is
determined by the temperature of the released and entrained snow but also
increases by frictional processes with time. For three artificially released
avalanches, we conducted snow profiles along the avalanche track and in the
deposition area, which allowed quantifying the temperature of the eroded snow
layers. This data set allowed to calculate the thermal balance, from release
to deposition, and to discuss the magnitudes of different sources of thermal
energy of the avalanches. For the investigated dry avalanches, the thermal
energy increase due to friction was mainly depending on the effective
elevation drop of the mass of the avalanche with a warming of approximately
0.3 °C per 100 vertical metres. Contrarily, the temperature change due to
entrainment varied for the individual avalanches, from −0.08 to
0.3 °C, and depended on the temperature of the snow along the path
and the erosion depth. Infrared radiation thermography (IRT) was used to
assess the surface temperature before, during and just after the avalanche
with high spatial resolution. This data set allowed to identify the warmest
temperatures to be located in the deposits of the dense core. Future research
directions, especially for the application of IRT, in the field of thermal
investigations in avalanche dynamics are discussed. |
| |
|
| Teil von |
|
|
|
|
|
|
|
|