Michalezyk et al. (2025) Evaluation and Attribution of a Warm Winter Bias over Arctic Sea Ice in a Climate Model

⚠️ Warning: This summary was generated from the abstract only, as the full text was not available.

Identification

• Journal: Journal of Climate
• Year: 2025
• Date: 2025-11-25
• Authors: Nicolas Michalezyk, Guillaume Gastineau, Martin Vancoppenolle, Clément Rousset
• DOI: 10.1175/jcli-d-24-0482.1

Research Groups

Institut Pierre Simon Laplace (IPSL)

Short Summary

This study evaluates near-surface air temperature biases in the IPSL-CM6A-LR climate model over Arctic sea ice, revealing a persistent winter warm bias ranging from +0.4 °C to +3.1 °C, primarily attributed to excessive poleward atmospheric heat transport and underestimated summertime sea ice cover in the coupled configuration.

Objective

• To evaluate the near-surface air temperature biases over Arctic sea ice in the atmosphere-only and coupled configurations of the IPSL-CM6A-LR climate model.
• To understand the origin of these biases through an energy budget analysis.

Study Configuration

• Spatial Scale: Pan-Arctic perennial ice zone, Arctic sea ice.
• Temporal Scale: 1980–2014 (35 years), focusing on winter periods.

Methodology and Data

• Models used: IPSL-CM6A-LR (atmosphere-only and fully coupled configurations).
• Data sources:
  • ERA5 reanalysis (with a linear correction applied for known Arctic winter warm bias).
  • In situ measurements.
  • Satellite-based remote sensing products.
  • Pan-Arctic energy budget analysis.

Main Results

• A winter warm bias over Arctic sea ice is evident in both model configurations:
  • Atmosphere-only IPSL-CM6A-LR: +0.4 °C warm bias.
  • Fully coupled IPSL-CM6A-LR: +3.1 °C warm bias.
• This warm bias is primarily attributed to excess poleward atmospheric heat transport.
• In the coupled model, the bias is further amplified by an underestimated summertime sea ice cover, despite a deficit in net oceanic heat transport.

Contributions

• Quantified the magnitude of winter near-surface air temperature biases in the IPSL-CM6A-LR model over Arctic sea ice using a robust multi-observational dataset evaluation, including a corrected ERA5 reference.
• Identified excessive poleward atmospheric heat transport as the primary driver of the warm bias in both model configurations.
• Highlighted the additional amplification of the bias in the coupled model due to underestimated summertime sea ice cover.
• Proposed a methodology for bias evaluation and understanding that can be applied in multimodel assessments to improve Arctic climate projections.

Funding

The paper does not explicitly list specific funding projects, programs, or reference codes.

Citation

@article{Michalezyk2025Evaluation,
  author = {Michalezyk, Nicolas and Gastineau, Guillaume and Vancoppenolle, Martin and Rousset, Clément},
  title = {Evaluation and Attribution of a Warm Winter Bias over Arctic Sea Ice in a Climate Model},
  journal = {Journal of Climate},
  year = {2025},
  doi = {10.1175/jcli-d-24-0482.1},
  url = {https://doi.org/10.1175/jcli-d-24-0482.1}
}