Avalanche danger level characteristics from field observations of snow instability
Avalanche danger levels are described in qualitative terms that mostly are not amenable to measurements or observations. However, estimating and improving forecast consistency and accuracy require descriptors that can be observed or measured. Therefore, we aim to characterize the avalanche danger le...
Published in: | The Cryosphere |
---|---|
Main Authors: | , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
Copernicus Publications
2021
|
Subjects: | |
Online Access: | https://doi.org/10.5194/tc-15-3293-2021 https://doaj.org/article/1a066d35af2142ee89956cdf989b2aca |
id |
ftdoajarticles:oai:doaj.org/article:1a066d35af2142ee89956cdf989b2aca |
---|---|
record_format |
openpolar |
spelling |
ftdoajarticles:oai:doaj.org/article:1a066d35af2142ee89956cdf989b2aca 2023-05-15T18:32:28+02:00 Avalanche danger level characteristics from field observations of snow instability J. Schweizer C. Mitterer B. Reuter F. Techel 2021-07-01T00:00:00Z https://doi.org/10.5194/tc-15-3293-2021 https://doaj.org/article/1a066d35af2142ee89956cdf989b2aca EN eng Copernicus Publications https://tc.copernicus.org/articles/15/3293/2021/tc-15-3293-2021.pdf https://doaj.org/toc/1994-0416 https://doaj.org/toc/1994-0424 doi:10.5194/tc-15-3293-2021 1994-0416 1994-0424 https://doaj.org/article/1a066d35af2142ee89956cdf989b2aca The Cryosphere, Vol 15, Pp 3293-3315 (2021) Environmental sciences GE1-350 Geology QE1-996.5 article 2021 ftdoajarticles https://doi.org/10.5194/tc-15-3293-2021 2022-12-31T06:43:57Z Avalanche danger levels are described in qualitative terms that mostly are not amenable to measurements or observations. However, estimating and improving forecast consistency and accuracy require descriptors that can be observed or measured. Therefore, we aim to characterize the avalanche danger levels based on expert field observations of snow instability. We analyzed 589 field observations by experienced researchers and forecasters recorded mostly in the region of Davos (Switzerland) during 18 winter seasons (2001–2002 to 2018–2019). The data include a snow profile with a stability test (rutschblock, RB) and observations on snow surface quality, drifting snow, signs of instability and avalanche activity. In addition, observers provided their estimate of the local avalanche danger level. A snow stability class ( very poor , poor , fair , good , very good ) was assigned to each profile based on RB score, RB release type and snowpack characteristics. First, we describe some of the key snowpack characteristics of the data set. In most cases, the failure layer included persistent grain types even after a recent snowfall. We then related snow instability data to the local avalanche danger level. For the danger levels 1–Low to 4–High , we derived typical stability distributions. The proportions of profiles rated poor and very poor clearly increased with increasing danger level. For our data set, the proportions were 5 %, 13 %, 49 % and 63 % for the danger levels 1–Low to 4–High , respectively. Furthermore, we related the local avalanche danger level to the occurrence of signs of instability such as whumpfs, shooting cracks and recent avalanches. The absence of signs of instability was most closely related to 1–Low and the presence of them to 3–Considerable . Adding the snow stability class and the 3 d sum of new snow depth improved the discrimination between the lower three danger levels. Still, 2–Moderate was not well described. Nevertheless, we propose some typical situations that approximately characterize each ... Article in Journal/Newspaper The Cryosphere Directory of Open Access Journals: DOAJ Articles The Cryosphere 15 7 3293 3315 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
Environmental sciences GE1-350 Geology QE1-996.5 |
spellingShingle |
Environmental sciences GE1-350 Geology QE1-996.5 J. Schweizer C. Mitterer B. Reuter F. Techel Avalanche danger level characteristics from field observations of snow instability |
topic_facet |
Environmental sciences GE1-350 Geology QE1-996.5 |
description |
Avalanche danger levels are described in qualitative terms that mostly are not amenable to measurements or observations. However, estimating and improving forecast consistency and accuracy require descriptors that can be observed or measured. Therefore, we aim to characterize the avalanche danger levels based on expert field observations of snow instability. We analyzed 589 field observations by experienced researchers and forecasters recorded mostly in the region of Davos (Switzerland) during 18 winter seasons (2001–2002 to 2018–2019). The data include a snow profile with a stability test (rutschblock, RB) and observations on snow surface quality, drifting snow, signs of instability and avalanche activity. In addition, observers provided their estimate of the local avalanche danger level. A snow stability class ( very poor , poor , fair , good , very good ) was assigned to each profile based on RB score, RB release type and snowpack characteristics. First, we describe some of the key snowpack characteristics of the data set. In most cases, the failure layer included persistent grain types even after a recent snowfall. We then related snow instability data to the local avalanche danger level. For the danger levels 1–Low to 4–High , we derived typical stability distributions. The proportions of profiles rated poor and very poor clearly increased with increasing danger level. For our data set, the proportions were 5 %, 13 %, 49 % and 63 % for the danger levels 1–Low to 4–High , respectively. Furthermore, we related the local avalanche danger level to the occurrence of signs of instability such as whumpfs, shooting cracks and recent avalanches. The absence of signs of instability was most closely related to 1–Low and the presence of them to 3–Considerable . Adding the snow stability class and the 3 d sum of new snow depth improved the discrimination between the lower three danger levels. Still, 2–Moderate was not well described. Nevertheless, we propose some typical situations that approximately characterize each ... |
format |
Article in Journal/Newspaper |
author |
J. Schweizer C. Mitterer B. Reuter F. Techel |
author_facet |
J. Schweizer C. Mitterer B. Reuter F. Techel |
author_sort |
J. Schweizer |
title |
Avalanche danger level characteristics from field observations of snow instability |
title_short |
Avalanche danger level characteristics from field observations of snow instability |
title_full |
Avalanche danger level characteristics from field observations of snow instability |
title_fullStr |
Avalanche danger level characteristics from field observations of snow instability |
title_full_unstemmed |
Avalanche danger level characteristics from field observations of snow instability |
title_sort |
avalanche danger level characteristics from field observations of snow instability |
publisher |
Copernicus Publications |
publishDate |
2021 |
url |
https://doi.org/10.5194/tc-15-3293-2021 https://doaj.org/article/1a066d35af2142ee89956cdf989b2aca |
genre |
The Cryosphere |
genre_facet |
The Cryosphere |
op_source |
The Cryosphere, Vol 15, Pp 3293-3315 (2021) |
op_relation |
https://tc.copernicus.org/articles/15/3293/2021/tc-15-3293-2021.pdf https://doaj.org/toc/1994-0416 https://doaj.org/toc/1994-0424 doi:10.5194/tc-15-3293-2021 1994-0416 1994-0424 https://doaj.org/article/1a066d35af2142ee89956cdf989b2aca |
op_doi |
https://doi.org/10.5194/tc-15-3293-2021 |
container_title |
The Cryosphere |
container_volume |
15 |
container_issue |
7 |
container_start_page |
3293 |
op_container_end_page |
3315 |
_version_ |
1766216577326252032 |