A Flexible Snow Model (FSM 2.1.1) including a forest canopy

Essery, Richard; Mazzotti, Giulia; Barr, Sarah; Jonas, Tobias; Quaife, Tristan; Rutter, Nick

doi:https://doi.org/10.5194/gmd-18-3583-2025

Articles | Volume 18, issue 12

https://doi.org/10.5194/gmd-18-3583-2025

© Author(s) 2025. This work is distributed under
the Creative Commons Attribution 4.0 License.

https://doi.org/10.5194/gmd-18-3583-2025

© Author(s) 2025. This work is distributed under
the Creative Commons Attribution 4.0 License.

Articles | Volume 18, issue 12

Model description paper

|

18 Jun 2025

Model description paper |

| 18 Jun 2025

A Flexible Snow Model (FSM 2.1.1) including a forest canopy

Richard Essery, Giulia Mazzotti, Sarah Barr, Tobias Jonas, Tristan Quaife, and Nick Rutter

Data sets

Snow-Vegetation-Atmosphere Interactions over Heterogeneous Landscapes Project: Vegetation and meteorological observations at the Abisko site Richard Essery et al. http://catalogue.ceda.ac.uk/uuid/6947880b98d32e249a8638ebe768efd2/

Snow-Vegetation-Atmosphere Interactions over Heterogeneous Landscapes Project: Vegetation and Meteorological Observations at the Sodankyla Site Richard Essery et al. http://catalogue.ceda.ac.uk/uuid/9c8c86ed78ae4836a336d45cbb6a757c/

Northern Hemisphere blended snow extent and snow mass time series L. Mudryk https://doi.org/10.18164/cc133287-1a07-4588-b3b8-40d714edd90e

MODIS/Terra+Aqua BRDF/Albedo Model Parameters Daily L3 Global -- 500m V061 C. Schaaf and Z. Wang https://doi.org/10.5067/MODIS/MCD43A1.061

IMS Daily Northern Hemisphere Snow and Ice Analysis at 1 km, 4 km, and 24 km resolutions US National Ice Center https://doi.org/10.7265/N52R3PMC

Model code and software

FSM version 2.1.1 revision for Geophysical Model Development paper Richard Essery https://doi.org/10.5281/zenodo.14950260

Scripts to produce figures for FSM 2.1.1 paper revision to GMD Richard Essery https://doi.org/10.5281/zenodo.14950395

Short summary

How forests influence accumulation and melt of snow on the ground is of long-standing interest, but uncertainty remains in how best to model forest snow processes. We developed the Flexible Snow Model version 2 to quantify these uncertainties. In a first model demonstration, how unloading of intercepted snow from the forest canopy is represented is responsible for the largest uncertainty. Global mapping of forest distribution is also likely to be a large source of uncertainty in existing models.