Aker et al. (2026) Impact of climate forcing time step in an ice-sheet firn model

Identification

• Journal: ˜The œcryosphere
• Year: 2026
• Date: 2026-09-24
• Authors: Tesse E. A. van den Aker, Peter Kuipers Munneke, Willem Jan van de Berg, Walter Willem Immerzeel, M. R. van den Broeke
• DOI: 10.5194/tc-20-5475-2026

Research Groups

• Institute for Marine and Atmospheric Research, Utrecht University, Utrecht, the Netherlands
• Department of Physical Geography, Utrecht University, Utrecht, the Netherlands

Short Summary

This study investigates the impact of climate forcing time step on firn models, specifically focusing on the IMAU-FDM model. The results show that increasing the climate forcing time step leads to more pore space in the firn layer, with a significant increase in areas with limited melt and high accumulation.

Objective

• Investigate the effect of climate forcing time step on firn models
• Analyze the impact of different climate forcing time steps on firn pore space creation and depletion

Study Configuration

• Spatial Scale: Regional scale, focusing on the Antarctic Peninsula Ice Sheet (APIS) and southern Greenland Ice Sheet (GrIS)
• Temporal Scale: 1979-2023 for APIS and 1 September 1939-31 December 2023 for GrIS

Methodology and Data

• Models used: IMAU-FDM v1.2A (APIS) and IMAU-FDM v1.2G (GrIS)
• Data sources: RACMO2.3p2, dynamically downscaled ERA5 reanalysis data

Main Results

• Increasing climate forcing time step leads to more pore space in the firn layer
• Areas with limited melt and high accumulation show significant increases in 1FAC
• The diurnal cycle in the input data plays a crucial role in the creation of pore space
• Model parameterizations can become unsuitable when applied outside the physical conditions or climate forcing time step

Contributions

• This study highlights the importance of considering the climate forcing time step in firn models
• The results provide new insights into the processes governing firn pore space creation and depletion
• The findings have implications for ice sheet mass balance projections and vulnerability assessments

Funding

• This research was funded by the European Research Council (ERC) under grant agreement No. 716092

Citation

@article{Aker2026Impact,
  author = {Aker, Tesse E. A. van den and Munneke, Peter Kuipers and Berg, Willem Jan van de and Immerzeel, Walter Willem and Broeke, M. R. van den},
  title = {Impact of climate forcing time step in an ice-sheet firn model},
  journal = {˜The œcryosphere},
  year = {2026},
  doi = {10.5194/tc-20-5475-2026},
  url = {https://doi.org/10.5194/tc-20-5475-2026}
}