---
DOAJ_listed: '1'
OA_place: publisher
OA_type: gold
PlanS_conform: '1'
_id: '21915'
abstract:
- lang: eng
text: Hydrological models commonly use very simple snow accumulation and melt models
based on air temperature information, namely, a temperature threshold for snow
accumulation as well as for snowmelt, and a melt factor. This utility emerges
due to the simplicity, efficiency, and generally good performance of such models
if sufficient calibration information is available. At scales beyond single gauged
catchments, the estimation and evaluation of the temperature thresholds and the
melt factor has been difficult due to a lack of observations on snow accumulation
and melt. Using a recently published Northern Hemisphere snow water equivalent
dataset (NH-SWE) and co-located climate station observations of temperature and
precipitation (4736 stations across the Northern Hemisphere), this work estimates
melt factors and temperature thresholds for snow modelling based on station observations
and provides the first large-scale and long-term (1950–2023) evaluation of a simple
temperature-index snow model and its parameters across a diverse range of snow
climates. Our study reveals that the 0 °C as precipitation-phase threshold captures
most snowfall days (89 %) and the 0 °C as snowmelt initiation threshold captures
most snowmelt days (76 %). Adjusting large-scale uniform threshold values does
not consistently improve performance across all snow accumulation and melt metrics.
Estimated melt factors based on observations converge towards 3–5 mm (°C d)−1
for deeper snowpack climates (peak snow water equivalent >300 mm), but their estimation
may be more challenging for colder climates with shallower snowpacks (<300 mm),
conditions where the derived melt factors cover a wider range (1 to 12 mm (°C d)−1)
and a much higher interannual and spatial variability. The temperature-index snow
model performs consistently well, on average, across the available Northern Hemisphere
data set for estimating long-term mean values of seasonal snow cover onset, snowmelt
season onset, mean snow accumulation and snowmelt rates, but challenges may arise
due to biases in temperature records or solid precipitation undercatch. Peak snow
water equivalent is likely underestimated for deep or alpine snowpacks, while
it is likely overestimated for shallow snowpacks in the coldest and continental
climates. The best median performance of the temperature-index approach lies on
relatively shallow snowpacks in temperate climates. This study provides valuable
insights into temperature-threshold snowfall modelling and temperature-index melt
modelling for applications across diverse climates and environments, and the results
should help refine regional modelling approaches to enhance our understanding
of snowpack responses to global warming.
acknowledgement: 'AFB acknowledges funding from the UK''s Natural Environment Research
Council (NERC) CENTA2 doctoral training program, grant number NE/S007350/1. AFB
acknowledges support from the School of Geography, Earth and Environmental Science
research fund. The computations described in this paper were performed using the
University of Birmingham''s BlueBEAR HPC service, which provides a High Performance
Computing service to the University''s research community. See http://www.birmingham.ac.uk/bear
(last access: 15 December 2025) for more details. This research has been supported
by the Natural Environment Research Council (grant no. CENTA2 NE/S007350/1).'
article_processing_charge: Yes
article_type: original
author:
- first_name: Adrià
full_name: Fontrodona-Bach, Adrià
id: f06891fd-9f42-11ee-8632-a20971c43046
last_name: Fontrodona-Bach
- first_name: Bettina
full_name: Schaefli, Bettina
last_name: Schaefli
- first_name: Ross
full_name: Woods, Ross
last_name: Woods
- first_name: Joshua R.
full_name: Larsen, Joshua R.
last_name: Larsen
citation:
ama: Fontrodona-Bach A, Schaefli B, Woods R, Larsen JR. Estimating robust melt factors
and temperature thresholds for snow modelling across the Northern Hemisphere.
Hydrology and Earth System Sciences. 2026;30(9):2613-2636. doi:10.5194/hess-30-2613-2026
apa: Fontrodona-Bach, A., Schaefli, B., Woods, R., & Larsen, J. R. (2026). Estimating
robust melt factors and temperature thresholds for snow modelling across the Northern
Hemisphere. Hydrology and Earth System Sciences. Copernicus Publications.
https://doi.org/10.5194/hess-30-2613-2026
chicago: Fontrodona-Bach, Adrià, Bettina Schaefli, Ross Woods, and Joshua R. Larsen.
“Estimating Robust Melt Factors and Temperature Thresholds for Snow Modelling
across the Northern Hemisphere.” Hydrology and Earth System Sciences. Copernicus
Publications, 2026. https://doi.org/10.5194/hess-30-2613-2026.
ieee: A. Fontrodona-Bach, B. Schaefli, R. Woods, and J. R. Larsen, “Estimating robust
melt factors and temperature thresholds for snow modelling across the Northern
Hemisphere,” Hydrology and Earth System Sciences, vol. 30, no. 9. Copernicus
Publications, pp. 2613–2636, 2026.
ista: Fontrodona-Bach A, Schaefli B, Woods R, Larsen JR. 2026. Estimating robust
melt factors and temperature thresholds for snow modelling across the Northern
Hemisphere. Hydrology and Earth System Sciences. 30(9), 2613–2636.
mla: Fontrodona-Bach, Adrià, et al. “Estimating Robust Melt Factors and Temperature
Thresholds for Snow Modelling across the Northern Hemisphere.” Hydrology and
Earth System Sciences, vol. 30, no. 9, Copernicus Publications, 2026, pp.
2613–36, doi:10.5194/hess-30-2613-2026.
short: A. Fontrodona-Bach, B. Schaefli, R. Woods, J.R. Larsen, Hydrology and Earth
System Sciences 30 (2026) 2613–2636.
corr_author: '1'
date_created: 2026-05-24T22:01:32Z
date_published: 2026-05-04T00:00:00Z
date_updated: 2026-06-02T09:24:00Z
day: '04'
ddc:
- '550'
department:
- _id: FrPe
doi: 10.5194/hess-30-2613-2026
file:
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creator: dernst
date_created: 2026-06-02T09:22:26Z
date_updated: 2026-06-02T09:22:26Z
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language:
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month: '05'
oa: 1
oa_version: Published Version
page: 2613-2636
publication: Hydrology and Earth System Sciences
publication_identifier:
eissn:
- 1607-7938
issn:
- 1027-5606
publication_status: published
publisher: Copernicus Publications
quality_controlled: '1'
scopus_import: '1'
status: public
title: Estimating robust melt factors and temperature thresholds for snow modelling
across the Northern Hemisphere
tmp:
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legal_code_url: https://creativecommons.org/licenses/by/4.0/legalcode
name: Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)
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...