Journal cover Journal topic
Natural Hazards and Earth System Sciences An interactive open-access journal of the European Geosciences Union
Journal topic

Journal metrics

IF value: 3.102
IF3.102
IF 5-year value: 3.284
IF 5-year
3.284
CiteScore value: 5.1
CiteScore
5.1
SNIP value: 1.37
SNIP1.37
IPP value: 3.21
IPP3.21
SJR value: 1.005
SJR1.005
Scimago H <br class='widget-line-break'>index value: 90
Scimago H
index
90
h5-index value: 42
h5-index42
Preprints
https://doi.org/10.5194/nhess-2019-433
© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.
https://doi.org/10.5194/nhess-2019-433
© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.

  04 Mar 2020

04 Mar 2020

Review status
A revised version of this preprint was accepted for the journal NHESS and is expected to appear here in due course.

Sensitivity of modeled snow stability data to meteorological input uncertainty

Bettina Richter1, Alec van Herwijnen1, Mathias W. Rotach2, and Jürg Schweizer1 Bettina Richter et al.
  • 1WSL Institute for Snow and Avalanche Research SLF, Davos, Switzerland
  • 2Institute for Atmospheric and Cryospheric Sciences, University of Innsbruck, Innsbruck, Austria

Abstract. To perform spatial snow cover simulations for numerical avalanche forecasting, interpolation and downscaling of meteorological data are required, which introduce uncertainties. The repercussions of these uncertainties on modeled snow stability remain mostly unknown. We therefore assessed the contribution of meteorological input uncertainty on modeled snow stability by performing a global sensitivity analysis. We used the numerical snow cover model SNOWPACK to simulate two snow instability metrics, i.e. the skier stability index and the critical crack length, for a field site equipped with an automatic weather station providing the necessary input for the model. Uncertainty ranges for meteorological forcing covered typical differences observed within a distance of 2 km and an elevation change of 200 m. Three different scenarios were investigated to better assess the influence of meteorological forcing on snow stability during a) the weak layer formation period, b) the slab formation period, and c) the weak layer and slab formation period. For each scenario, 14 000 simulations were performed, by introducing quasi-random uncertainties to the meteorological input. Results showed that a weak layer formed in 99.7 % of the simulations, indicating that the weak layer formation was very robust due to the prolonged dry period. For scenario a), modeled grain size of the weak layer was mainly sensitive to precipitation, while the shear strength of the weak layer was sensitive to most input variables, especially air temperature. Once the weak layer existed (case b), precipitation was the most prominent driver for snow stability. The sensitivity analysis highlighted that for all scenarios, the two stability metrics were mostly sensitive precipitation. Precipitation determined the load of the slab, which in turn influenced weak layer properties. For case b) and c), the two stability metrics showed contradicting behaviors. With increasing precipitation, i.e. deep snowpacks, the skier stability index decreased (less stable). In contrast, the critical crack length increased with increasing precipitation. With regard to spatial simulations of snow stability, the high sensitivity on precipitation suggests that accurate precipitation patterns are necessary to obtain realistic snow stability patterns. With regard to spatial simulations of snow stability, the high sensitivity on precipitation suggests that accurate precipitation patterns are necessary to obtain realistic snow stability patterns.

Bettina Richter et al.

Interactive discussion

Status: closed
Status: closed
AC: Author comment | RC: Referee comment | SC: Short comment | EC: Editor comment
Printer-friendly Version - Printer-friendly version Supplement - Supplement

Interactive discussion

Status: closed
Status: closed
AC: Author comment | RC: Referee comment | SC: Short comment | EC: Editor comment
Printer-friendly Version - Printer-friendly version Supplement - Supplement

Bettina Richter et al.

Bettina Richter et al.

Viewed

Total article views: 353 (including HTML, PDF, and XML)
HTML PDF XML Total BibTeX EndNote
267 74 12 353 15 14
  • HTML: 267
  • PDF: 74
  • XML: 12
  • Total: 353
  • BibTeX: 15
  • EndNote: 14
Views and downloads (calculated since 04 Mar 2020)
Cumulative views and downloads (calculated since 04 Mar 2020)

Viewed (geographical distribution)

Total article views: 288 (including HTML, PDF, and XML) Thereof 287 with geography defined and 1 with unknown origin.
Country # Views %
  • 1
1
 
 
 
 

Cited

Saved

No saved metrics found.

Discussed

No discussed metrics found.
Latest update: 17 Sep 2020
Publications Copernicus
Download
Short summary
We investigated the sensitivity of modeled snow instability to uncertainties in meteorological input, typically found in complex terrain. The formation of the weak layer was very robust due to the long dry period, indicated a widespread avalanche problem. Once a weak layer has formed, precipitation mostly determined slab and weak layer properties and hence, snow instability. When spatially assessing snow instability for avalanche forecasting, accurate precipitation patterns have to be known.
We investigated the sensitivity of modeled snow instability to uncertainties in meteorological...
Citation
Altmetrics