Published May 28, 2026 | Version v1

Climate Variability and West Antarctic Ice Sheet Collapse

  • 1. ROR icon Alfred-Wegener-Institut Helmholtz-Zentrum für Polar- und Meeresforschung

Description

Dataset: Climate Variability and West Antarctic Ice Sheet Collapse

Zenodo Data Repository

Authors:
Javier Blasco¹, Jan Swierczek-Jereczek²·³, Marisa Montoya²·³, Jorge Alvarez-Solas³, Alexander Robinson¹

Affiliations:
¹ Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Potsdam, Germany
² Department of Earth Physics and Astrophysics, Complutense University of Madrid, Madrid, Spain
³ Geosciences Institute, CSIC–UCM, Madrid, Spain

Model: Yelmo ice-sheet model v1.14
Domain: Antarctic Ice Sheet (AIS), 16 km resolution
Simulation period: 1990–3500 CE
Associated manuscript: Manuscript in preparation.

Overview

This dataset contains 1D timeseries statistics and 2D spatial snapshots from an ensemble of Antarctic ice-sheet simulations designed to quantify the role of climate variability on the timing and magnitude of West Antarctic Ice Sheet (WAIS) collapse. The ensemble applies five levels of deterministic atmospheric warming (ΔT = 4, 6, 8, 10, 12 K) combined with stochastic climate variability drawn from historical reanalysis (ORAS5/ERA5, 1990–2019). A parallel set of no-variability (NCV) runs provides the deterministic baseline for each scenario.

A sensitivity experiment isolating the contributions of oceanic (OCN) and atmospheric (ATM) variability components is also included for the ΔT = 10 K scenario.

Directory structure

1D_data/    — CSV timeseries (statistics across 100-member ensemble)
2D_data/    — NetCDF spatial snapshots at selected years

1D_data — CSV files

All CSV files cover the period 2020–3500 CE. Years are stored as floating-point values (e.g. 2020.0).

Ensemble statistics (with climate variability)

Columns: year, median, q25, q75, min, max

File pattern Variable Region Unit
slc_{region}_{dT}.csv Sea-level contribution (SLC) WAIS / EAIS / AIS m
ag_{region}_{dT}.csv Grounded-ice area WAIS / EAIS / AIS 10⁶ km²
  • {region} ∈ {wais, eais, ais}
  • {dT} ∈ {dT4, dT6, dT8, dT10, dT12}

Example: slc_wais_dT10.csv — WAIS sea-level contribution for ΔT = 10 K, ensemble spread.

No-variability deterministic runs (NCV baseline)

Columns: year, slc (SLC files) or year, area (area files)

File pattern Variable Region Unit
slc_{region}_{dT}_ncv.csv Sea-level contribution WAIS / EAIS / AIS m
ag_{region}_{dT}_ncv.csv Grounded-ice area WAIS / EAIS / AIS 10⁶ km²

SLR acceleration distribution

Per-member peak sea-level rise rate within the 2500–3500 CE window.

Columns: member_id, peak_year, peak_rate_mm_yr

File pattern Region
slr_accel_dist_{region}_{dT}.csv WAIS / EAIS / AIS

Forcing timeseries

NCV deterministic forcingforcing_atm_ncv.csv, forcing_ocn_ncv.csv
Columns: year, dT4, dT6, dT8, dT10, dT12
Atmospheric (ΔT_atm, K) and oceanic (ΔT_ocn, K) forcing anomalies for each dT scenario.

Ensemble variability forcingforcing_atm_var_dT{X}.csv, forcing_ocn_var_dT{X}.csv
Columns: year, median, q25, q75, min, max
Per-timestep statistics of the stochastic variability component across the 100-member ensemble.

Individual noise trajectoriesforcing_var_members.csv
Columns: year, atm_m1, ..., atm_m10, ocn_m1, ..., ocn_m10
First 10 ensemble members' variability trajectories (used for spaghetti plots).

WAIS volume flux (dVidt) — for Figures 3 and 4

File Description Columns
dvidt_wais_ncv.csv NCV dV/dt for all dT year, dT4, dT6, dT8, dT10, dT12
dvidt_wais_envelope_{dT}.csv Per-timestep envelope max across ensemble year, dv_max
dvidt_wais_peaks_{dT}.csv Per-member peak rate and year member_id, peak_year, peak_rate
dvidt_wais_envelope_ocn_dT10.csv OCN-only ensemble envelope year, dv_max
dvidt_wais_envelope_atm_dT10.csv ATM-only ensemble envelope year, dv_max
dvidt_wais_peaks_ocn_dT10.csv OCN-only per-member peak years member_id, peak_year
dvidt_wais_peaks_atm_dT10.csv ATM-only per-member peak years member_id, peak_year

Units: dV/dt in mm SLR / yr (conversion factor: −0.00247 m³/yr ice → mm SLR/yr)

2D_data — NetCDF files

All 2D files use the ANT-16KM polar stereographic grid.
Dimensions: x (316), y (316) — grid spacing 16 km.
Coordinates: xc, yc in km.

Figure 3: ice thickness anomaly and grounding at NCV peak year

Files: fig3_{dT}.nc — one file per scenario (dT6, dT8, dT10, dT12)

Variable Description Unit
mean_dH_anom Ensemble mean ice thickness anomaly minus NCV (H̄ᵥ − H_nv) m
std_dH Ensemble standard deviation of ice thickness anomaly m
mean_fgrnd Ensemble mean grounded fraction %
fgrnd_ncv NCV grounded fraction (binary 0/1)

Global attributes: scenario, peak_year (year of NCV peak dV/dt used as snapshot time), snap_year.

Figure 4: OCN/ATM sensitivity at fixed target years (ΔT = 10 K)

Files: fig4_dT10_yr{year}.nc — one file per target year (2800, 2900, 2950, 3000)

Variable Description Unit
mean_fgrnd_atm_ocn ATM+OCN ensemble mean grounded fraction %
mean_fgrnd_ocn OCN-only ensemble mean grounded fraction %
mean_fgrnd_atm ATM-only ensemble mean grounded fraction %
fgrnd_ncv NCV grounded fraction (binary 0/1)

Global attributes: dT, snap_year.

Note on grounded fraction: Values represent the fraction of ensemble members (0–100%) for which a given grid cell is grounded at the snapshot year. Values of 100% (shown as grey in figures) indicate that all members remain grounded — the ice sheet has not yet retreated at that location.

Ensemble design

Parameter Value
Ensemble size 100 members per scenario
Variability source Stochastic resampling from ORAS5/ERA5 1990–2019
Forcing scenarios ΔT_atm = 4, 6, 8, 10, 12 K (1pctCO2-equivalent ramp)
Ice-sheet model Yelmo v1.14, 16 km Antarctic domain
Ocean forcing ESM-derived thermal forcing (ORAS5 base + variability)
Sensitivity experiment OCN-only and ATM-only variability at ΔT = 10 K (100 members each)

License

Creative Commons Attribution 4.0 International (CC BY 4.0)
Please cite the associated manuscript when using this data.

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