Intrinsic Variability of Sea Level from Global Ocean Simulations: Spatiotemporal Scales

• DOI: 10.1175/jcli-d-14-00554.1
• Publication Date: 2014-12-18T16:18:19Z
• Authors: Guillaume Sérazin; Thierry Penduff; Sandy Grégorio; Bernard Barnier; Jean-Marc Molines; Laurent Terray
• Keywords: Ocean dynamics

Abstract In high-resolution ocean general circulation models (OGCMs), as in process-oriented models, a substantial amount of interannual to decadal variability is generated spontaneously by oceanic nonlinearities: that is, without any the atmospheric forcing at these time scales. The authors investigate temporal and spatial scales which this intrinsic has strongest imprints on sea level anomalies (SLAs) using ° global OGCM, comparing “hindcast” driven full range with its counterpart forced repeated climatological seasonal cycle. Outputs from both simulations are compared within distinct frequency–wavenumber bins. fully hindcast shown reproduce observed distribution magnitude low-frequency SLA very accurately. small-scale ( L < 6°) variance all scales, barely sensitive almost entirely origin. high-frequency (mesoscale) part have identical geographical distributions, supporting hypothesis nonlinear inverse cascade transferring kinetic energy high low frequencies. large-scale > 12°) mostly related over most ocean, but it remain largely three eddy-active regions: Gulf Stream, Kuroshio, Antarctic Circumpolar Current (ACC). Compared ¼° predecessor, authors’ OGCM yield stronger variability, mesoscale