Item

Abstract

Numerical tide simulations for the Arctic Ocean under glacial conditions imply a macro- to megatidal regime in contrast to its present-day microtidal regime. Applying a barotropic ocean tide model, we study the sensitivity of this regime change driven by the semidiurnal M2 tide to a set of modeling parameters. We find that the near-resonant tidal oscillation system is sensitive to changes in the paleobathymetry due to glacial isostatic adjustment, as well as to the effect of ocean self-attraction and loading, resulting in an amplification of the dominant M2 tide by a factor of up to 4. Furthermore, the modeling framework is used to investigate the back effect of the Arctic resonance on the world oceans. This feedback contributes +289 GW of internal wave dissipation (13% of the global figure). The results are contextualized by an analytical model of cylindrical symmetry. This model illustrates the driving mechanism for the amplified glacial Arctic tide regime as an interplay of shelf and deep-ocean resonance at semidiurnal frequencies.