Vignon et al. (2026) Intermediate-complexity parameterisation of blowing snow in the ICOLMDZ AGCM: development and first applications in Antarctica

Identification

• Journal: Geoscientific model development
• Year: 2026
• Date: 2026-01-08
• Authors: Étienne Vignon, Nicolas Chiabrando, Cécile Agosta, Charles Amory, Valentin Wiener, Justine Charrel, Thomas Dubos, Christophe Genthon
• DOI: 10.5194/gmd-19-239-2026

Research Groups

• Laboratoire de Météorologie Dynamique-IPSL, Sorbonne Université/CNRS/Ecole Normale Supérieure-PSL Université/Ecole Polytechnique-Institut Polytechnique de Paris, Paris, France
• Laboratoire des Sciences du Climat et de l’Environnement, LSCE/IPSL, CEA-CNRS-UVSQ, Université Paris-Saclay, Gif-sur-Yvette, France
• Univ. Grenoble Alpes/CNRS/IRD/G-INP/INRAE, Institut des Geosciences de l’Environnement, Grenoble, France
• Laboratoire de Physique et Chimie de l’Environnement et de l’Espace (LPC2E), Université d’Orléans, CNRS UMR7328, CNES, Orléans, France

Short Summary

This study develops and evaluates an intermediate-complexity blowing snow parameterization for the ICOLMDZ atmospheric general circulation model. The parameterization significantly modifies the Antarctic Surface Mass Balance (SMB), causing a decrease in net snow accumulation in escarpment regions and an increase along the coast.

Objective

• To develop and evaluate an intermediate-complexity blowing snow parameterization for the ICOLMDZ atmospheric general circulation model (AGCM), balancing physical detail with computational efficiency.
• To investigate the relevance and justification of accounting for blowing snow processes in global climate models, particularly their impact on the Antarctic surface mass balance (SMB) and polar hydrological cycle.

Study Configuration

• Spatial Scale:
  • Regional: Adélie Land, Antarctica, with a horizontal resolution of 20 km and 95 η vertical levels (first model level at approximately 8 m above ground level).
  • Global: Antarctic ice sheet, with a horizontal resolution of approximately 150 km (nbp = 60) and 95 η vertical levels.
• Temporal Scale:
  • Regional: 1 year (2011).
  • Global: 5 years (2000–2004).

Methodology and Data

• Models used:
  • ICOLMDZ AGCM (atmospheric component of the IPSL Coupled Model), comprising:
    • DYNAMICO icosahedral dynamical core.
    • LMDZ AGCM physics (CMIP7 version, based on CMIP6).
    • New TKE-l turbulent diffusion scheme (Vignon et al., 2024).
    • Intermediate-complexity blowing snow parameterization (developed in this study), treating blowing snow as an independent water species.
    • Simple snow scheme for land-ice surfaces (LMDZ model).
• Data sources:
  • In situ observations (Adélie Land, Antarctica):
    • D17 station (138.7° E, 67.4° S): Near-surface air temperature, humidity, wind speed (6 levels along a 7 m mast), and blowing snow horizontal mass flux (2G-FlowCapt™ sensor, 0-1 m above ground level).
    • D47 station (139.9° E, 66.7° S): Temperature, humidity, wind (automatic weather station at ~2.8 m for wind, ~2.2 m for T/RH), and blowing snow horizontal mass flux (two 2G-FlowCapt™ sensors, 0-1 m and 1-2 m above ground level).
    • SR50 acoustic depth sensor at D47 for surface elevation.
    • Processed dataset from Amory et al. (2020).
  • Reanalysis data:
    • ERA5 reanalysis (Hersbach et al., 2020) for sea surface temperature, sea-ice cover, lateral forcing (regional simulations), and nudging of wind components (global simulations).
  • Antarctic Surface Mass Balance (SMB) observations:
    • GLACIOCLIM-SAMBA dataset (Favier et al., 2013; updated by Wang et al., 2016).
    • Accumulation estimates from Medley et al. (2014) over the Amundsen Sea coast.
  • Topography data:
    • Schaffer and Timmermann (2016) dataset, based on Bedmap-2 product.

Main Results

• Regional Simulations (Adélie Land):
  • The model satisfactorily reproduces summer wind speed, temperature, and the timing of blowing snow events.
  • Blowing snow flux magnitudes are reasonably reproduced, though an underestimation at D47 coincides with underestimated wind speeds.
  • In winter, blowing snow intensity and occurrences are overestimated near the coast, correlating with a positive wind speed bias.
  • The model exhibits comparable performance to the regional atmospheric model MAR in simulating year-round blowing snow occurrences.
  • Blowing snow leads to a moderate near-surface cooling (due to latent heat of sublimation) and a pronounced humidification (locally exceeding 10% in relative humidity) in the boundary layer, extending offshore.
  • The presence of blowing snow clouds increases the yearly averaged downward longwave radiative flux at the surface, partially offset by a decrease in net shortwave flux and surface turbulent sensible heat flux, resulting in a limited net surface warming (e.g., +0.2 K at D47).
• Global Simulations (Antarctica):
  • An increase of several percent in total cloud cover and near-surface relative humidity is observed along the Antarctic periphery due to blowing snow sublimation.
  • The Antarctic SMB is significantly modified: an overall decrease in net snow accumulation is simulated in the escarpment region (due to surface snow erosion), and an increase is observed along the coast (due to blowing snow deposition and increased snowfall from weakened precipitation sublimation in the humidified boundary layer).
  • Local SMB differences can reach several tens of kilograms per square meter per year (kg m⁻² yr⁻¹).
  • The additional computational cost of activating the blowing snow parameterization is approximately 4%.

Contributions

• Development and implementation of an intermediate-complexity blowing snow parameterization for the ICOLMDZ AGCM, designed for numerical stability and low computational cost in global climate simulations.
• Comprehensive evaluation of the parameterization's performance in both regional (Adélie Land) and global Antarctic simulations against in situ observations.
• Quantification of the significant impact of blowing snow on the Antarctic surface mass balance (SMB), revealing distinct regional changes (decrease inland, increase coastal) and its influence on boundary layer thermodynamics and radiative fluxes.
• Introduction of a "double implicit" numerical treatment for blowing snow sublimation, enhancing stability for typical AGCM time steps.
• Provides strong arguments for the inclusion of blowing snow processes in global climate models, particularly for studies focusing on polar regions and cryosphere-atmosphere coupling.

Funding

• European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (grant no. 951596) through the AWACA project.
• DEPHY research group, funded by CNRS/INSU and Météo-France.
• PEPR TRACCS project (no. ANR-22-EXTR-0008) funded by the Agence Nationale de la Recherche – France 2030.
• HPC resources of IDRIS and TGCC under allocations gen15038, WUU AD010111116R2, and LMD AD010107632R3 attributed by GENCI (Grand Equipement National de Calcul Intensif).
• CALVA project (https://web.lmd.jussieu.fr/~cgenthon/SiteCALVA/) with support from the French polar Institute (IPEV project 1013).

Citation

@article{Vignon2026Intermediatecomplexity,
  author = {Vignon, Étienne and Chiabrando, Nicolas and Agosta, Cécile and Amory, Charles and Wiener, Valentin and Charrel, Justine and Dubos, Thomas and Genthon, Christophe},
  title = {Intermediate-complexity parameterisation of blowing snow in the ICOLMDZ AGCM: development and first applications in Antarctica},
  journal = {Geoscientific model development},
  year = {2026},
  doi = {10.5194/gmd-19-239-2026},
  url = {https://doi.org/10.5194/gmd-19-239-2026}
}