A linear thermohaline oscillator driven by stochastic atmospheric forcing
Abstract
The interdecadal variability of a stochastically forced four-box model of the oceanic meridional thermohaline circulation (THC) is described and compared to the THC variability in the coupled ocean-atmosphere GCM of Delworth, Manabe, and Stouffer (1993). The box model is placed in a linearly stable thermally dominant mean state under mixed boundary conditions. A linear stability analysis of this state reveals one damped oscillatory THC mode in addition to purely damped modes. The variability of the model under a moderate amount of stochastic forcing, meant to emulate the random variability of the atmosphere affecting the coupled model's interdecadal THC variability, is studied. A linear interpretation, in which the damped oscillatory mode is of primary importance, is sufficient for understanding the mechanism accounting for the stochastically forced variability. Direct comparison of the variability in the box model and coupled GCM reveals common qualitative aspects. Such a comparison supports, although does not verify, the hypothesis that the coupled model's THC variability can be interpreted as the result of atmospheric weather exciting a linear damped oscillatory THC mode.
Keywords
Cite
@article{arxiv.ao-sci/9502002,
title = {A linear thermohaline oscillator driven by stochastic atmospheric forcing},
author = {Stephen M. Griffies and Eli Tziperman},
journal= {arXiv preprint arXiv:ao-sci/9502002},
year = {2016}
}
Comments
Paper accepted by Journal of Climate. This is a Latex source file. Figures are included in an adjacent uuencoded file. Directions for uncompressing are pre-pended to the figures. User may wish to obtain postscript version from http://www.gfdl.gov/~smg/pointers/geo_physics_abstracts/GT.html Revisions are merely due to changes in e-print submission format; paper's content has not changed.