Brief communication: Arctic sea ice thickness internal variability and its changes under historical and anthropogenic forcing

Van Achter, Guillian [UCL] Ponsoni, Leandro [UCL] Massonnet, François [UCL] Fichefet, Thierry [UCL] Legat, Vincent [UCL]

We use model simulations from the CESM1-CAM5-BGC-LE dataset to characterise the Arctic sea ice thickness internal variability both spatially and temporally. These properties, and their stationarity, are investigated in three different contexts: (1) constant pre-industrial, (2) historical and (3) projected conditions. Spatial modes of variability show highly stationary patterns regardless of the forcing and mean state. A temporal analysis reveals two peaks of significant variability, and despite a non-stationarity on short timescales, they remain more or less stable until the first half of the 21st century, where they start to change once summerice-free events occur, after 2050.