Global ocean/sea-ice simulations performed by the DRAKKAR Group show that (even partially) resolving mesoscale structures substantially enhances the simulated sea-level variability at interannual timescales, and brings it close to levels measured by altimetry. This increase is largely due to the emergence of an intrinsic low-frequency variability component that (i) has a strong imprint on various observed variables and oceanic climate indices, (ii) is not simulated by laminar ocean models used in most existing climate prediction systems, and (iii) has a chaotic character. Part of the interannual sea-level variability is thus not directly driven by interannual atmospheric variability. This article presents recent model results about the imprints of this poorly-known but significant intrinsic variability on satellite observations (sea-level anomalies, sea-surface temperature) and other climate indices (mixed layer depth, current transports, Atlantic meridional overturning circulation). Possible implications are then discussed.
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