The leaky funnel model, a metaphor of the ventilation of the World Ocean as simulated in an OGCM
Mouchet, A.; Deleersnijder, E. (2008). The leaky funnel model, a metaphor of the ventilation of the World Ocean as simulated in an OGCM. Tellus, Ser. A, Dyn. meteorol. oceanogr. 60(4): 761-774. dx.doi.org/10.1111/j.1600-0870.2008.00322.x In: Tellus. Series A: Dynamic Meteorology and Oceanography. Blackwell: Copenhagen. ISSN 0280-6495; e-ISSN 1600-0870, more | |
Abstract | It is seen that an idealized model may suggest an appropriate scaling of the water age in the World Ocean, which is a measure of the ventilation rate. We use a 1-D advection-diffusion model in which the deep ocean is represented as a leaky funnel, allowing recirculation towards the surface. The analytical solutions to the steady-state problem are readily obtained. The three parameters of the leaky funnel model are estimated in such a way that the behaviour of the domain-averaged water age be as similar as possible to that derived from a 3-D model in a series of sensitivity runs. The agreement between both sets of mean ages is excellent, with a linear correlation coefficient very close to unity. A good agreement is also found for the age of radioactive tracers and the associated radioages. The parameters of the leaky funnel model have a clear physical meaning, that is, the order of magnitude of the horizontal velocity, the mean length of water parcel trajectories in the deep ocean, and a horizontal diffusivity scale. The values of all of them turn out to be consistent with our current knowledge of the World Ocean circulation. |
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