Sensitivity of basinwide meridional overturning to diapycnal diffusion and remote wind forcing in an idealized Atlantic southern Ocean geometry

• Main Authors: Barry A. Klinger, Sybren Drijfhout, Jochem Marotzke
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Published: 2003
• Subjects: Bilt; The Netherlands; Southern Ocean; North Atlantic Deep Water; North Atlantic
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.654.3360; http://eprints.soton.ac.uk/255/1/KLINGER_.MARTOZKE_JPO__S_2001.pdf

Recent numerical experiments indicate that the rate of meridional overturning as-sociated with North Atlantic Deep Water is controlled both by mixing and by windstress in the Southern Ocean, where the zonal periodicity of the domain alters the nature of the ow. We nd a simple approximate expression for meridional overturning as a solution to Gnanadesikan's (1999) cubic scale relation. We compare the predicted overturning to coarse-resolution numerical experiments with an idealized Atlantic-Ocean/Southern Ocean geometry. The scaling accurately predicts the sensitivity to forcing for experiments with a level model employing isopycnal diusion of temperature, salinity, and \layer thickness". A layer model produces similar results, increasing our condence in the numerics of both mod-els. Level model experiments with horizontal diusivity have similar qualitative behavior but somewhat dierent sensitivity to forcing. We highlight the dierence in meridional overturning induced by changes in wind-stress or vertical diusivity. Wind-driven circulation anomalies outside the region of wind-stress perturbation include strongly cross-isopycnal ow near the surface and approximately