The sea level rise of the 8.2 ka event simulated by the iCESM1.3

The 8.2 ka event can be a benchmark for present-day climate under the influence of freshwater release from ice-melt. However, the total volume of freshwater release of the 8.2 ka event remains controversial in reconstructions. Isotope-enabled Earth system models provide a critical tool for direct comparison with paleoclimate records, offering a potential resolution to these discrepancies. This study utilizes the isotope-embedded earth system model iCESM1.3 and employs the simplified freshwater release mode of “isosceles triangle-like” to quantitatively simulate the 8.2 ka event. The simulation of freshwater release starts at 8.3 ka BP and initially releases 2.5 Sverdrup (Sv) of freshwater in one year (analogous to the lake outburst, ~ 0.22 m). Meanwhile, using the release mode of “isosceles triangle-like”, the peak time of release has been set at 8.215 ka BP, with a peak release amount of 0.19 Sv (analogous to the ice-sheet saddle collapse, ~ 1.41 m). The simulation results have successfully reproduced the characteristics of the 8.2 ka event as recorded. This estimation of sea level rise by “isosceles triangle-like” mode is smaller than that of “rectangular pulses-like” mode. The direct isotope comparison between the simulation and records is promising to reconcile the disagreement among the data.