Separating snow and ice melt using water stable isotopes and glacio-hydrological modelling: towards improving the application of isotope analyses in highly glacierized catchments

<p>Glacio-hydrological models are widely used for estimating current and future streamflow across spatial scales, utilizing various data sources, notably observed streamflow and snow and/or ice accumulation, as well as ablation observations. However, modelling highly glacierized catchments po...

Full description

Saved in:
Bibliographic Details
Main Authors: T. Müller, M. Fischer, S. N. Lane, B. Schaefli
Format: Article
Language:English
Published: Copernicus Publications 2025-01-01
Series:The Cryosphere
Online Access:https://tc.copernicus.org/articles/19/423/2025/tc-19-423-2025.pdf
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1832582887070760960
author T. Müller
T. Müller
M. Fischer
M. Fischer
S. N. Lane
B. Schaefli
B. Schaefli
B. Schaefli
author_facet T. Müller
T. Müller
M. Fischer
M. Fischer
S. N. Lane
B. Schaefli
B. Schaefli
B. Schaefli
author_sort T. Müller
collection DOAJ
description <p>Glacio-hydrological models are widely used for estimating current and future streamflow across spatial scales, utilizing various data sources, notably observed streamflow and snow and/or ice accumulation, as well as ablation observations. However, modelling highly glacierized catchments poses challenges due to data scarcity and complex spatio-temporal meteorological conditions, leading to input data uncertainty and potential misestimation of the contribution of snow and ice melt to streamflow. Some studies propose using water stable isotopes to estimate shares of rain, snow and ice in streamflow, yet the choice of the isotopic composition of these water sources significantly impacts results.</p> <p>This study presents a combined isotopic and glacio-hydrological model which provides catchment-integrated snow and ice melt isotopic compositions during an entire melting season. These isotopic compositions are then used to estimate the seasonal shares of snow and ice melt in streamflow for the Otemma catchment in the Swiss Alps. The model leverages available meteorological station data (air temperature, precipitation and radiation), ice mass balance data and snow cover maps to model and automatically calibrate the catchment-scale snow and ice mass balances. The isotopic module, building on prior work by <span class="cit" id="xref_text.1"><a href="#bib1.bibx2">Ala-Aho et al.</a> (<a href="#bib1.bibx2">2017</a><a href="#bib1.bibx2">a</a>)</span>, estimates seasonal isotopic compositions of precipitation, snow and ice. The runoff generation and transfer module relies on a combined routing and reservoir approach and is calibrated based on measured streamflow and isotopic data.</p> <p>Results reveal challenges in distinguishing snow and ice melt isotopic values in summer, rendering a reliable separation between the two sources difficult. The modelling of catchment-wide snowmelt isotopic composition proves challenging due to uncertainties in precipitation lapse rate, mass exchanges during rain-on-snow events and snow fractionation. The study delves into these processes and their impact on model results and suggests guidelines for future models. It concludes that water stable isotopes alone cannot reliably separate snow and ice melt shares for temperate alpine glaciers. However, combining isotopes with glacio-hydrological modelling enhances hydrologic parameter identifiability, in particular those related to runoff transfer to the stream, and improves mass balance estimations.</p>
format Article
id doaj-art-dacb3d2569484ea68820629d73c19c31
institution Kabale University
issn 1994-0416
1994-0424
language English
publishDate 2025-01-01
publisher Copernicus Publications
record_format Article
series The Cryosphere
spelling doaj-art-dacb3d2569484ea68820629d73c19c312025-01-29T07:16:20ZengCopernicus PublicationsThe Cryosphere1994-04161994-04242025-01-011942345810.5194/tc-19-423-2025Separating snow and ice melt using water stable isotopes and glacio-hydrological modelling: towards improving the application of isotope analyses in highly glacierized catchmentsT. Müller0T. Müller1M. Fischer2M. Fischer3S. N. Lane4B. Schaefli5B. Schaefli6B. Schaefli7Institute of Earth Surface Dynamics, University of Lausanne, Lausanne, SwitzerlandInstitute of Geography, University of Bern, Bern, SwitzerlandInstitute of Geography, University of Bern, Bern, SwitzerlandOeschger Centre for Climate Change Research, University of Bern, Bern, SwitzerlandInstitute of Earth Surface Dynamics, University of Lausanne, Lausanne, SwitzerlandInstitute of Earth Surface Dynamics, University of Lausanne, Lausanne, SwitzerlandInstitute of Geography, University of Bern, Bern, SwitzerlandOeschger Centre for Climate Change Research, University of Bern, Bern, Switzerland<p>Glacio-hydrological models are widely used for estimating current and future streamflow across spatial scales, utilizing various data sources, notably observed streamflow and snow and/or ice accumulation, as well as ablation observations. However, modelling highly glacierized catchments poses challenges due to data scarcity and complex spatio-temporal meteorological conditions, leading to input data uncertainty and potential misestimation of the contribution of snow and ice melt to streamflow. Some studies propose using water stable isotopes to estimate shares of rain, snow and ice in streamflow, yet the choice of the isotopic composition of these water sources significantly impacts results.</p> <p>This study presents a combined isotopic and glacio-hydrological model which provides catchment-integrated snow and ice melt isotopic compositions during an entire melting season. These isotopic compositions are then used to estimate the seasonal shares of snow and ice melt in streamflow for the Otemma catchment in the Swiss Alps. The model leverages available meteorological station data (air temperature, precipitation and radiation), ice mass balance data and snow cover maps to model and automatically calibrate the catchment-scale snow and ice mass balances. The isotopic module, building on prior work by <span class="cit" id="xref_text.1"><a href="#bib1.bibx2">Ala-Aho et al.</a> (<a href="#bib1.bibx2">2017</a><a href="#bib1.bibx2">a</a>)</span>, estimates seasonal isotopic compositions of precipitation, snow and ice. The runoff generation and transfer module relies on a combined routing and reservoir approach and is calibrated based on measured streamflow and isotopic data.</p> <p>Results reveal challenges in distinguishing snow and ice melt isotopic values in summer, rendering a reliable separation between the two sources difficult. The modelling of catchment-wide snowmelt isotopic composition proves challenging due to uncertainties in precipitation lapse rate, mass exchanges during rain-on-snow events and snow fractionation. The study delves into these processes and their impact on model results and suggests guidelines for future models. It concludes that water stable isotopes alone cannot reliably separate snow and ice melt shares for temperate alpine glaciers. However, combining isotopes with glacio-hydrological modelling enhances hydrologic parameter identifiability, in particular those related to runoff transfer to the stream, and improves mass balance estimations.</p>https://tc.copernicus.org/articles/19/423/2025/tc-19-423-2025.pdf
spellingShingle T. Müller
T. Müller
M. Fischer
M. Fischer
S. N. Lane
B. Schaefli
B. Schaefli
B. Schaefli
Separating snow and ice melt using water stable isotopes and glacio-hydrological modelling: towards improving the application of isotope analyses in highly glacierized catchments
The Cryosphere
title Separating snow and ice melt using water stable isotopes and glacio-hydrological modelling: towards improving the application of isotope analyses in highly glacierized catchments
title_full Separating snow and ice melt using water stable isotopes and glacio-hydrological modelling: towards improving the application of isotope analyses in highly glacierized catchments
title_fullStr Separating snow and ice melt using water stable isotopes and glacio-hydrological modelling: towards improving the application of isotope analyses in highly glacierized catchments
title_full_unstemmed Separating snow and ice melt using water stable isotopes and glacio-hydrological modelling: towards improving the application of isotope analyses in highly glacierized catchments
title_short Separating snow and ice melt using water stable isotopes and glacio-hydrological modelling: towards improving the application of isotope analyses in highly glacierized catchments
title_sort separating snow and ice melt using water stable isotopes and glacio hydrological modelling towards improving the application of isotope analyses in highly glacierized catchments
url https://tc.copernicus.org/articles/19/423/2025/tc-19-423-2025.pdf
work_keys_str_mv AT tmuller separatingsnowandicemeltusingwaterstableisotopesandglaciohydrologicalmodellingtowardsimprovingtheapplicationofisotopeanalysesinhighlyglacierizedcatchments
AT tmuller separatingsnowandicemeltusingwaterstableisotopesandglaciohydrologicalmodellingtowardsimprovingtheapplicationofisotopeanalysesinhighlyglacierizedcatchments
AT mfischer separatingsnowandicemeltusingwaterstableisotopesandglaciohydrologicalmodellingtowardsimprovingtheapplicationofisotopeanalysesinhighlyglacierizedcatchments
AT mfischer separatingsnowandicemeltusingwaterstableisotopesandglaciohydrologicalmodellingtowardsimprovingtheapplicationofisotopeanalysesinhighlyglacierizedcatchments
AT snlane separatingsnowandicemeltusingwaterstableisotopesandglaciohydrologicalmodellingtowardsimprovingtheapplicationofisotopeanalysesinhighlyglacierizedcatchments
AT bschaefli separatingsnowandicemeltusingwaterstableisotopesandglaciohydrologicalmodellingtowardsimprovingtheapplicationofisotopeanalysesinhighlyglacierizedcatchments
AT bschaefli separatingsnowandicemeltusingwaterstableisotopesandglaciohydrologicalmodellingtowardsimprovingtheapplicationofisotopeanalysesinhighlyglacierizedcatchments
AT bschaefli separatingsnowandicemeltusingwaterstableisotopesandglaciohydrologicalmodellingtowardsimprovingtheapplicationofisotopeanalysesinhighlyglacierizedcatchments